ORIGINAL ARTICLE
The Journal of Nursing Research h VOL. 23, NO. 1, MARCH 2015
Revision and Validation of a Scale to Assess Pregnancy Stress Chung-Hey Chen PhD, RN, Professor, Institute of Allied Health Sciences and Department of Nursing, National Cheng Kung University.
ABSTRACT Background: Pregnancy is a potentially stressful event. Prenatal stress alters maternal endocrine and immune systems, has been implicated in the etiology of prenatal complications or postnatal psychiatric disorders, and may adversely affect fetal health. The 30-item Pregnancy Stress Rating Scale (PSRS), initially developed in 1983 by Chen and colleagues, is the only measure to date designed specifically to evaluate prenatal stress. Purpose: The purpose of this study was to reconsider and revise the 30-item PSRS and validate the new PSRS. Methods: A cross-sectional design was used. Adding new items of pregnancy stress generated from clinical experience and expert recommendations resulted in a 40-item revised PSRS that was more reflective of current social conditions. Three hundred pregnant women, recruited from the antenatal clinic of a medical center in southern Taiwan, completed the revised PSRS to assess its internal consistency, testYretest reliability, construct validity, and convergent and discriminate validity. Results: The final 36-item PSRS (PSRS36) was derived by deleting four items with relatively low itemYtotal correlation coefficients or factor loadings. The resultant 36-item scale showed good internal consistency (! = .92) and 2-week testYretest reliability (r = .82). Factor analysis confirmed construct validity and suggested five prenatal stress dimensions, which explained 52.17% of the total variance. Convergent and discriminate validities were indicated by significant correlations among the PSRS36, Perceived Stress Scale, and Interpersonal Support Evaluation List. Conclusions: The PSRS36 is a psychometrically sound and practical tool for nurses and other healthcare providers to assess prenatal stress and to examine intervention protocols in Taiwanese prenatal women. More research is recommended to determine whether the PSRS36 may be used in other racial-ethnic groups.
(Beydoun & Saftlas, 2008). Growing evidence relates prenatal maternal stress to increases in serum levels of corticotrophinreleasing hormone, adrenocorticotropic hormone, and cortisol. Increases in these three hormones activate proinflammatory cytokine (Interleukin 6) production in the expectant mother’s immune system (Coussons-Read, Okun, & Nettles, 2007; Ruiz & Avant, 2005). Maternal stress hormones are also transmitted across the placenta and thus affect the fetal development of the hypothalamicYpituitaryYadrenal axis, limbic system, and the prefrontal cortex (Van den Bergh, Mulder, Mennes, & Glover, 2005). These prenatal stress-related biological changes may lead to unfavorable outcomes in pregnancy such as spontaneous abortion, preterm birth, low birth weight (Hobel, Goldstein, & Barrett, 2008; Mulder et al., 2002), developmental delays (Ruiz & Avant, 2005), temperamental and behavioral problems in toddlers (Gutteling et al., 2005), and postpartum mood disorder (Beydoun & Saftlas, 2008). It is therefore important to have an appropriate instrument to measure women’s prenatal stress. In 1983, Chen and colleagues developed the first Pregnancy Stress Rating Scale (PSRS) to measure a wide range of concerns unique to pregnant women. This 30-item instrument measures the perceptions of respondents to a variety of stressful concerns on a 5-point Likert scale ranging from 0 (definitely no) to 4 (very severe). Chen and colleagues tested the PSRS with 250 Taiwanese subjects in their third trimester of pregnancy (Chen, Yu, & Hwang, 1983). Three categories of psychological stressors were identified through factor analysis: (a) navigating safely through pregnancy, labor, and delivery; (b) identifying with the maternal role; and (c) coping with altered body structure, image, and function. These three factors were then used in further studies (Chen, Chen, & Huang, 1989; Chen, Huang, & Ke, 1991).
KEY WORDS: pregnancy stress, prenatal care, instrument development.
Introduction Pregnancy is a stressful event (Affonso & Mayberry, 1990; Van den Bergh, Mulder, Mennes, & Glover, 2005). Belief in the noxious health effects of prenatal maternal stress has been widespread since the age of Hippocrates, although intensive research in this area did not emerge until the early 1970s
Accepted for publication: February 17, 2014 *Address correspondence to: Chung-Hey Chen, No. 1, University Road, Tainan City 70101, Taiwan, ROC. Tel: +886 (6) 235-3535 ext. 5846; Fax: +886 (6) 237-7550; E-mail: [email protected] Cite this article as: Chen, C. H. (2015). Revision and validation of a scale to assess pregnancy stress. The Journal of Nursing Research, 23(1), 25Y32. doi:10.1097/jnr.0000000000000047
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The PSRS has been widely used in Mandarin-speaking societies to assess stress in pregnant women. Taiwanese investigators Kuo, Lee, Lee, and Liu (2002) found primary stressors for women receiving assisted reproductive techniques (ARTS) to be (in order of eigenvalue) as follows: (a) the health and safety of mother and child, (b) physical figure and activity changes, and (c) and maternal role identification. They found a significantly lower psychological stress response to maternal role identification in the assisted reproductive techniques group than the control group. Wang, Chung, Chou, and Chiang (2006) identified the top three stressors for Southeast Asian immigrant mothers living in Taiwan to be the normalcy, safe delivery, and health of their infants. Wang (2008) used the PSRS to track pregnancy stress in 200 Taiwanese mothers during each trimester and a follow-up infant temperament questionnaire at 4-month postpartum. She found no significant difference in PSRS scores from each trimester between mothers of infants with a difficult temperament and those infants whose temperament was calmer. At least three investigators have used the PSRS in China. For example, Liu, Guo, and Yuan (2006) used the scale on 206 pregnant women in Beijing and found their main stressor to be the concern about the health and safety of the mother and the fetus. The Chinese version of the PSRS was the first scale designed to measure stress unique to the pregnancy experience in Taiwan, including potentially stressful pregnancy-related events and anticipated events during the labor, delivery, and immediate postpartum periods. English-language instruments designed to measure stress include the Perceived Stress Scale (PSS), life events inventory, and perceived stress questionnaire, each of which focus on major life events; the daily hassles scale, which focuses on cumulative minor stressors; and combinations of these instruments (Fliege et al., 2005; Ruiz & Fullerton, 1999). Life event measures use a global definition of stress and thus offer little opportunity to be prescriptive about stressors or develop interventions (Ruiz & Avant, 2005; Ruiz & Fullerton, 1999). Therefore, more definitive measures of prenatal stress are needed to extend our understanding of this issue and suggest effective interventions. Changes in society significantly influence perceived prenatal stressors. The 1983 PSRS, designed to explore prenatal stress in Taiwanese women, thus may need updating to fit today’s social conditions. Significant Taiwanese social changes that a revised scale should consider include (a) the larger percentage of immigrant mothers receiving maternal care in Taiwan (Lee, Chen, & Chen, 2010), (b) comparatively greater concern with body weight management during both prenatal and postnatal periods, (c) the decreased prevalence of extended families, (d) change in venue preference for postpartum care (the traditional practice of ‘‘doing-the-month’’) from the home to privately run postpartum service centers, and (e) the breastfeeding policy promoted by the Taiwan Ministry of Health and Welfare. This study was thus designed to update and revise the Chinese 30-item PSRS to reflect current social conditions and the impact of these conditions on today’s prenatal population in Taiwan. 26
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Methods A cross-sectional study was used to revise the Chinese version of PSRS and test its psychometric properties.
Participants The investigator recruited a convenience sample of 300 prenatal women from the antenatal clinic of a medical center in Tainan, southern Taiwan, over a 6-month period. Inclusion criteria were as follows: (a) over 18 years old, (b) over 17 weeks since last menses, (c) expected to have uncomplicated vaginal deliveries, (d) able to read Chinese, and (e) willing to participate in this study. Pregnant women who had experienced a fetal death or stillbirth were excluded. A sample size of 300 is adequate for factor analysis (Winter, Dodou, & Wieringa, 2009). The institutional review board of the target medical center approved the research protocol.
Measures Demographic data Participant demographic data that were collected included age, educational level, employment status, social class, gravidity, type of pregnancy, baby’s gender, feelings about the baby’s gender, prenatal complications, and marital satisfaction. The Index of Status Position was used to stratify social class (Lin, 1978). The social class of a nuclear family unit was estimated by combining the couple’s information on education and occupation. The Index of Status Position classifies social status into levels 1Y5. In this study, levels 1 and 2 were categorized as upper class, level 3 was categorized as middle class, and levels 4 and 5 were categorized as lower class. Revised pregnancy stress rating scale Chen and colleagues initially developed the 30-item Chinese version of PSRS to measure perceived prenatal stress in mothers in 1983. The preface to the PSRS provided to respondents is as follows: ‘‘The statements listed below describe pregnancy related stressors. You are asked to rate your CURRENT degree of concern, worry, or/and distress about pregnancy-related changes by indicating definitely no, mild, moderate, severe, or very severe in the appropriate column.’’ For this study, a 37-item revised PSRS was drafted that included seven new items (anticipated stressors during labor, delivery, and immediate postpartum) addressing social conditions and concerns/ worries currently prevalent among Taiwanese prenatal mothers. These new items included ‘‘deciding who will help take care of the baby,’’ ‘‘elder children expressing jealousy or dislike of the fetus,’’ ‘‘husband absence during labor,’’ ‘‘doctor attitudes during labor and delivery,’’ ‘‘nurse attitudes during labor and delivery,’’ ‘‘ability to breastfeed successfully,’’ and ‘‘returning to prenatal body shape and weight during the postnatal period.’’ Five experts critiqued the revised PSRS for item clarity and relevance. Two experts were specialists in maternity nursing
Pregnancy Stress Rating Scale
(one senior nursing faculty and one clinical supervisor), and three were obstetricians. Two pregnant women assessed the face validity of the revised scale. On the basis of expert recommendations, several items were reworded, and three new items were added, including ‘‘Adherence to pregnancy taboos is troublesome,’’ ‘‘I worry whether fetal movement is normal,’’ and ‘‘I have diminished sleep quality.’’ These revisions resulted in a revised 40-item instrument. Items were rated on a 5-point Likert scale ranging from 0 (definitely no) to 4 (very severe). The sum total of all item scores provided the prenatal stress score; higher values indicated higher perceived prenatal stress.
Perceived stress scale The 10-item PSS measures current stress caused by the respondent’s perceived diminished capacity to control or cope with life events (Cohen & Williamson, 1988). The PSS was used to determine how closely its measurements paralleled the revised PSRS for the same construct. The Chinese version of PSS had adequate testYretest reliability (r = .81, over a 2-week interval; Chen, Tseng, Wang, & Lee, 1994) and good internal consistency (Cronbach’s ! = .83Y.84; Chang, Chen, & Huang, 2008; Ko, Chang, & Chen, 2010). Internal consistency reliability (Cronbach’s !) was .87 in this study. Interpersonal support evaluation list Social support was measured using the 16-item Interpersonal Support Evaluation List (ISEL; Cohen, Mermelstein, Kamarch, & Hoberman, 1985). The scale measures four types of social support: tangible, appraisal, self-esteem, and belonging. Item scores range from 0 to 3, and higher scores indicate higher perceived social support. The Chinese version of the ISEL Short Form has adequate convergent validity (r = .55 with the Social Support Index), internal consistency (! = .81), and testYretest reliability (r = .77; Chen et al., 1994; Hung, Tsai, Ko, & Chen, 2013). In this study, internal consistency was adequate (! = .85).
Data Analysis Data were analyzed using SPSS for Windows version 17.0 (SPSS, Inc., Chicago, IL, USA). ItemYtotal correlation was conducted to evaluate items for retention in the scale. The criteria for deleting items were itemYtotal correlation of less than .30 (Polit & Beck, 2011). Cronbach’s ! was calculated to analyze the internal consistency reliability, and Pearson productYmoment correlation coefficient was used to demonstrate evidence of testYretest reliability. The construct validity for the new PSRS was evaluated using exploratory factor analysis. The following criteria were used: (a) the factor loading was greater than .30, (b) each dimension had an eigenvalue of 1 or more followed by a scree test, and (c) at least three items in each factor (Munro, 2005; Netemeyer, Bearden, & Sharma, 2003; Pett, Lackey, & Sullivan, 2003). The scale score distribution and its ceiling effect and floor effect were examined (McHorney, Ware, Rachel Lu, & Sherbourne, 1994). Pearson’s correlation coefficient was employed to test the convergent and discriminate validity. All results were considered significant at p G .05.
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Results Three hundred Taiwanese prenatal women completed the revised PSRS. The average age of participants was 31.6 T 4.1 years (range = 18Y44 years); most (n = 255, 85%) held a junior college degree or higher, 68.3% held full-time employment, slightly more than half (n = 155, 51.7%) were of high socioeconomic status, and just over one third (n = 110, 36.7%) were middle class. All (n = 300, 100%) were married, and most (n = 221, 73.7%) expressed satisfaction with married life. Table 1 shows the participants’ demographic characteristics. ItemYtotal correlations for the 40-item revised PSRS ranged from .13 to .68. Two items, ‘‘frequent uterus contractions and tightening’’ and ‘‘older children express jealousy or dislike of the fetus,’’ were removed as the itemYtotal correlation coefficients for these two fell below the threshold of .30 (Chiou, 2010). An exploratory factor analysis of the revised 38-item PSRS using an eigenvalue of 1.00 or greater as the cutoff point for factor extraction combined with a scree test was then conducted (Pett et al., 2003). This analysis indicated that a fivedimension model in which each dimension retains three or more items with salient loadings of more than .30 would be TABLE 1.
Participant Demographic Characteristics (N = 300) Variable
n
%
Education eSenior high school 9Senior high school
45 255
15.0 85.0
Occupation Employed Housewife
205 95
68.3 31.7
Socioeconomic status High Middle Low
155 110 35
51.7 36.7 11.6
Type of pregnancy Planned Unplanned
205 95
68.3 31.7
Baby gender Boy Girl Twin or unknown
126 126 48
42.0 42.0 16.0
Feelings about the baby’s gender Meets preference Does not meet preference No opinion
105 32 163
35.0 10.7 54.3
Prenatal complications No Yes
278 22
92.7 7.3
Marital satisfaction Satisfied Acceptable Dissatisfied
221 78 1
73.7 26.0 0.3
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best (Netemeyer et al., 2003). Two items were subsequently removed (‘‘I worry having a child will force me to stop working’’ and ‘‘Having a child will decrease my interest in social contacts and activities’’) because factor loadings fell below the threshold of .30 in all dimensions. The revised 36-item PSRS (PSRS36) was then subjected to a forced five-factor principal axis analysis followed by a Varimax rotation. Correlation matrix quality was high, as measured using KaiserYMeyerYOlkin (.88). A significant Bartlett test of sphericity (Chi-square = 5594.08, p G .001) justified the use of factor analysis as a
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dimension-reducing procedure. Table 2 shows factorial solutions (eigenvalues ranged from 1.56 to 10.28) and rotated loadings. Assignment of items to factors was mutually exclusive. The five-factor solution accounted for 52.17% of variance, with each factor accounting, respectively, for 28.54%, 7.33%, 6.57%, 5.39%, and 4.34% of the total variance for prenatal stress variables. The summed scores for the five factors formed the global PSRS36 score (range = 0Y144). As shown in Table , factor analysis was used to confirm the construct validity of the PSRS. Results supported the five
TABLE 2.
Principal Axis Factor Analysis of Pregnancy Stress Rating Scale Item Degree of Concern, Worry, or/and Distress
ITC Factor Loading
Factor 1: Stress from seeking safe passage for mother and child through pregnancy, labor, and delivery 1. Abnormal or difficult birth 2. Safe labor and delivery for my sake 3. Safe delivery for my baby’s sake 4. Doctor may not arrive on time at delivery 5. Premature labor 6. Doctor attitudes during labor and delivery 7. Nurse attitudes during labor and delivery 8. Husband’s absence during labor 9. Unbearable labor pain
.653 .669 .665 .637 .591 .709 .725 .566 .611
.784 .746 .744 .743 .738 .722 .707 .603 .519
Factor 2: Stress from baby care and changing family relationships 1. Breast or bottle feed my baby 2. Ability to breastfeed successfully 3. Ability to raise my baby successfully 4. Naming my baby 5. Sexual activity during pregnancy 6. Loss of free time after birth 7. Acceptance of the child by significant others 8. Increased financial burden 9. Support from family members or husband
.628 .640 .669 .514 .506 .494 .321 .530 .352
.695 .676 .618 .617 .565 .506 .442 .416 .361
Factor 3: Stress from maternal role identification 1. Baby’s appearance 2. Baby’s birth weight 3. Baby’s gender 4. Baby’s health 5. Concern about status of fetal movement 6. Adhering to traditional pregnancy mores 7. Maternal behavior influencing the fetus 8. Preparation of clothes and newborn supplies for baby
.496 .535 .434 .593 .588 .391 .427 .526
.671 .647 .560 .549 .548 .516 .501 .469
Factor 4: Stress from social support seeking 1. Finding a qualified baby-sitter 2. Deciding who will help take care of the baby 3. Choosing a place to ‘‘do-the-month’’ 4. Arranging for someone to handle housework during labor
.313 .449 .524 .465
.798 .789 .758 .692
Factor 5: Stress from altered physical appearance and function 1. Altered body shape during pregnancy 2. Controlling weight during pregnancy 3. Mobility difficulties due to altered body shape 4. Returning to prenatal body shape and weight during postnatal period 5. Dark brown areas appearing on the skin 6. Sleep quality
.400 .356 .332 .566 .409 .454
.740 .708 .666 .563 .554 .339
Note. ITC = itemYtotal correlation.
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factors as appropriate dimensions of prenatal stress: Factor 1, stress from seeking safe passage for mother and child through pregnancy, labor, and delivery (e.g., worry about ‘‘abnormal or difficult birth,’’ ‘‘safe labor and delivery for my sake,’’ ‘‘safe delivery for my baby’s sake’’); Factor 2, stress from baby care and changing family relationships (e.g., worry about ‘‘breast or bottle feed my baby,’’ ‘‘ability to breastfeed successfully,’’ ‘‘ability to raise my baby successfully’’); Factor 3, stress from maternal role identification (e.g., worry about ‘‘baby’s appearance,’’ ‘‘baby’s birth weight,’’ ‘‘baby’s gender’’); Factor 4, stress from social support seeking (e.g., worry about ‘‘finding a qualified baby-sitter,’’ ‘‘deciding who will help take care of the baby,’’ ‘‘choosing a place to do-the-month’’); Factor 5, stress from altered physical appearance and function (e.g., worry about ‘‘altered body shape during pregnancy,’’ ‘‘controlling weight during pregnancy,’’ ‘‘mobility difficulties due to altered body shape’’). The 300 pregnant women earned an average PSRS36 score of 53.96 T 21.04 (range = 10Y111). Moreover, 0.3% of the sample achieved the lowest score, and 1% achieved the highest score; the PSRS36 had trivial ceiling and floor effects. The alpha for each subscale of the PSRS36 was adequate, ranging from .73 to .91 (DeVellis, 2003). The PSRS36 had good internal consistency (Cronbach’s ! = .92), and 2-week testYretest reliability was .82 (n = 30), indicating stable PSRS36 responses. PSRS36 scores were positively correlated with PSS (r = .40, p G .001) and negatively correlated with ISEL (r = j.27, p G .001), supporting convergent and discriminate validities.
Discussion The original 1983 PSRS (Chen et al., 1983) was revised, and its dimensional structure was tested on a sample of prenatal women in Taiwan. The researcher expanded the questionnaire from 30 to 36 items. The PSRS36 achieved satisfactory psychometric characteristics in terms of reliability, construct validity, and convergent and discriminate validity. The PSRS36 addresses the five distinct prenatal stress dimensions of seeking safe passage for mother and child, baby care and changing family relationships, maternal role identification, social support seeking, and altered physical appearance and functions. The acceptable alpha coefficients (.73Y.91) for the five subscales indicated that five strong factors were formed in PSRS36, thus providing evidence of internal consistency and reliability and providing initial evidence of construct validity for a developing scale (Munro, 2005). The second and fourth dimensions were new additions that were not part of the original threedimension PSRS. The first dimension considers maternal safety in terms of physical well-being and the survival of both mother and child. The second dimension relates to anticipatory competence with regard to mothering, acceptance of the child by significant others, bonding with the child, and contemplations on the changing relationships between mother and child and other family members. The third dimension addresses the prenatal mother’s concerns about her baby’s appearance, gender, and
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well-being and the inherent conflicts that arise between fantasized ‘‘perfect’’ outcomes and dreaded ‘‘problem’’ outcomes. The fourth dimension addresses ‘‘nesting behavior’’ and the prenatal mother’s concerns related to providing a good home for her unborn child. The fifth dimension addresses the prenatal mother’s concerns related to altered physical appearance and functions and perceived loss of control over body functions. Considerations of the consequential basis of instrument interpretation cannot ignore the influence of social values and theoretical interpretations (Messick, 1980). Four items significantly associated with Taiwan-specific sociocultural systems were concentrated in the three dimensions of baby care and changing family relationships (Factor 2), maternal role identification (Factor 3), and social support seeking (Factor 4). These four items were ‘‘naming my baby,’’ ‘‘maternal behavior influencing the fetus,’’ ‘‘adhering to traditional pregnancy mores,’’ and ‘‘choosing a place to ‘do-the-month.’’’ An infant’s name, together with the time of birth, is believed to be crucial to ensuring her or his good fortune in life (Chang & Chen, 2005; Hung, 2006). Choosing an appropriate name for an infant before she or he is born is an activity that usually involves the extended family and potentially conflicting opinions. ‘‘Naming my baby’’ was thus included as a prenatal stress scale item on the PSRS36. Cultural rituals and social taboos heavily influence pregnancy and childbirth behavior (Lee et al., 2009), and these events may cause stress to women. A Hong Kong study found that all prenatal women surveyed followed at least one or more traditional prescription/proscription during pregnancy to avoid pregnancy loss or mishap and that about one quarter felt they had lost some freedom, were unhappy about such restrictions, and faced stress from intergenerational conflicts in this regard (Lee et al., 2009). Similarly, although many women in Taiwan are uncertain about the efficacy of these traditional mores, most choose to follow at least some as precautions against miscarriage, birth defects, and other imperfections (Chou, 2002; Lee et al., 2009) as well as to attract good fortune. It is observed that some prenatal women in Taiwan still adhere to ‘‘prenatal education’’ behaviors that include actively adjusting mind and mood to enhance embryo health and passively obeying dietary and behavioral taboos during pregnancy to nurture a ‘‘good’’ baby. The various prescriptions and proscriptions required when following these practices may intensify prenatal stress (Geller, 2004). Therefore, ‘‘maternal behavior influencing the fetus’’ and ‘‘adhering to traditional pregnancy mores’’ were two prenatal stress items in the PSRS36. Pregnant women may experience anticipated or floating stress about the future situation during the ‘‘doing-the-month’’ postpartum period. In the month after childbirth, Taiwanese mothers typically receive extra attention and support from the family and are allowed to rest. Their mothers, mothersin-law, sisters, and other female relatives are regarded as natural helpers during the ‘‘doing-the-month’’ postpartum period (Chen & Liu, 1995). Although living with her parents-in-law during this period is the traditional norm, care provided in 29
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these close quarters may exacerbate the often sensitive and easily conflictive relationship between the new mother and her mother-in-law (Chen & Liu, 1995). Although offering assistance during difficult times, the mother-in-law may also express criticism or disapproval of the postpartum behavior of her daughter-in-law, particularly in relation to infant care (Chen & Liu, 1995). Regarding the place for ‘‘doing the month,’’ postpartum service centers are an emerging institution in Taiwan offering an alternative to new mothers. Their popularity in recent years has grown because of the increased prevalence of nuclear families, decline of extended family households, and decreased availability of family support. Prenatal women in Taiwan thus worry about identifying a helper for their postpartum month and finding a suitable place to ‘‘do-the-month.’’ ‘‘Choosing a place to ‘do-the-month’’’ was thus included as a prenatal stress scale item on the PSRS36. The limitations of this study are that the revised PSRS36 was tested on prenatal women older than 18 years who were in the second or third trimester and who anticipated uncomplicated vaginal deliveries. Therefore, the revised PSRS36 may not be generalized to populations of prenatal women who do not meet these criteria. Despite this limitation, the results of this study highlight the significance of PSRS36 in providing a more appropriate scale to measure the unique pregnancy stress faced by expectant mothers in Taiwan. The psychometric qualities of the PSRS36 have important clinical and research implications. Nurses and other healthcare providers should assess psychological stress in prenatal women and provide care appropriate to the specific stressors involved to ensure the well-being of both mother and fetus through pregnancy, labor, and delivery. Accurately assessing stress in prenatal women may be useful not only to help these women cope with stress but also to guide the development of prenatal stress interventions such as stress prevention/resilience-building programs and support groups. Because some items on the PSRS36 are associated with Taiwanese cultural rituals and social taboos, further research is needed to assess the applicability of this scale to other ethnic groups and whether modification is necessary for use outside Taiwan and Taiwanese communities.
Acknowledgments This study was supported by a grant from the National Science Council of Taiwan. I am grateful to Dr. Carol Shieh, Associate Professor of Indiana University (United States), for ChineseY English translation validity check; to Professor Graeme Smith of Edinburgh Napier University (United Kingdom) for his editorial assistance with the PSRS36; and to the staff and the pregnant women who participated in the study.
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Beydoun, H., & Saftlas, A. S. (2008). Physical and mental health outcomes of prenatal maternal stress in human and animal studies: A review of recent evidence. Paediatric and Perinatal Epidemiology, 22(5), 438Y466. doi:10.1111/j.1365-3016.2008.00951.x Chang, M. Y., Chen, C. H., & Huang, K. F. (2008). Effects of music therapy on psychological health of women during pregnancy. Journal of Clinical Nursing, 17(19), 2580Y2587. doi:10.1111/j.13652702.2007.02064.x Chang, S. C., & Chen, C. H. (2005). Effects of music therapy on women’s physiologic measures, anxiety, and satisfaction during Cesarean delivery. Research in Nursing & Health, 28(6), 453Y461. doi:10 .1002/nur.20102 Chen, C. H., Chen, H. M., & Huang, T. H. (1989). Stressors associated with pregnancy as perceived by pregnant women during three trimesters. The Kaohsiung Journal of Medical Sciences, 5(9), 505Y509. Chen, C. H., Huang, H. L., & Ke, J. K. (1991). Psychological stressors perceived by high-risk and normal pregnant women during third trimester. The Journal of Nursing, 38(2), 91Y97. (Original work published in Chinese) Chen, C. H., & Liu, C. Y. (1995). Chinese culture and postpartum depression. The Journal of Nursing, 42(1), 91Y94. doi:10.6224/ JN.42.1.91 (Original work published in Chinese) Chen, C. H., Tseng, Y. F., Wang, S. Y., & Lee, J. N. (1994). The prevalence and predictors of postpartum depression. The Journal of Nursing Research, 2(3), 263Y274. Chen, C. H., Yu, Y. M., & Hwang, K. K. (1983). Psychological stressors perceived by pregnant women during their third trimester. Formosan Journal of Public Health, 10(1), 88Y98. (Original work published in Chinese) Chiou, H. J. (2010). Quantitative research and statistical analysis. Taipei City, Taiwan, ROC: Wu-Nan Books. Chou, C. H. (2002). Contemporary maternal infant care. In C. H. Chen, C. H. Chou, U. L. Chung, T. Y. Lee, S. W. Teng, & W. S. Chen (Eds.), Maternal newborn nursing (pp. 5Y17). Taipei, Taiwan, ROC: National Open University. (Original work published in Chinese) Cohen, S., Mermelstein, R., Kamarch, T., & Hoberman, H. M. (1985). Measuring the functional components of social support. In I. G. Sarason & B. R. Sarason (Eds.), Social support: Theory, research and applications (pp. 73Y94). Boston, MA: Martinus Nijhoff. doi:10.1007/978-94-009-5115-0_5 Cohen, S., & Williamson, G. M. (1988). Perceived stress in a probability sample of the United States. In S. Spacapan & S. Oskamp (Eds.), The social psychology of health (pp. 31Y67). Thousand Oaks, CA: Sage Publications. Coussons-Read, M. E., Okun, M. L., & Nettles, C. D. (2007). Psychosocial stress increases inflammatory markers and alters cytokine production across pregnancy. Brain, Behavior, and Immunity, 21(3), 343Y350. doi:10.1016/j.bbi.2006.08.006 DeVellis, R. F. (2003). Scale development: Theory and applications (2nd ed.). London, UK: Sage. Fliege, H., Rose, M., Arck, P., Walter, O. B., Kocalevent, R. D., Weber, C., & Klapp, B. F. (2005). The Perceived Stress Questionnaire (PSQ) reconsidered: Validation and reference values from different clinical and healthy adult samples. Psychosomatic Medicine, 67, 78Y88. doi:10.1097/01.psy.0000151491.80178.78 Geller, P. A. (2004). Pregnancy as a stressful life event. CNS Spectrums, 9(3), 188Y197.
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Gutteling, B. M., de Weerth, C., Willemsen-Swinkels, S. H., Huizink, A. C., Mulder, E. J., Visser, G. H., & Buitelaar, J. K. (2005). The effects of prenatal stress on temperament and problem behavior of 27-month-old toddlers. European Child & Adolescent Psychiatry, 14, 41Y51. doi:10.1007/s00787-005-0435-1 Hobel, C. J., Goldstein, A., & Barrett, E. S. (2008). Psychosocial stress and pregnancy outcome. Clinical Obstetrics and Gynecology, 51(2), 333Y348. doi:10.1097/GRF.0b013e31816f2709 Hung, C. H. (2006). Revalidation of the postpartum stress scale. Journal of Clinical Nursing, 15, 718Y725. doi:10.1111/j.13652702.2006.01609.x Hung, H. M., Tsai, P. S., Ko, S. H., & Chen, C. H. (2013). Patterns and predictors of sleep quality in Taiwanese pregnant women. MCN: The American Journal of Maternal/Child Nursing, 38(2), 95Y101. doi:10.1097/NMC.0b013e3182659345 Ko, S. H., Chang, S. C., & Chen, C. H. (2010). A comparative study of sleep quality between pregnant and non-pregnant Taiwanese women. Journal of Nursing Scholarship, 42(1), 23Y30. doi:10.1111/ j.1547-5069.2009.01326.x Kuo, B. J., Lee, L. J., Lee, S. H., & Liu, C. H. (2002). Psychological stress and its related factors during first trimester pregnancy in women who received assisted reproductive techniques. Chung Shan Medical Journal, 13(1), 69Y79. (Original work published in Chinese) Lee, D. T. S., Ngai, I. S. L., Ng, M. M. T., Lok, I. H., Yip, A. S. K., & Chung, T. K. H. (2009). Antenatal taboos among Chinese women in Hong Kong. Midwifery, 25(2), 104Y113. doi:10.1016/j.midw.2007 .01.008 Lee, L. C., Chen, J. Y., & Chen, C. H. (2010). Immigrant women and postpartum depression. The Journal of Nursing, 57(1), 106Y111. doi:10.6224/JN.57.1.106 (Original work published in Chinese) Lin, T. (1978). Psychiatry and society. Taipei, Taiwan, ROC: Chi-Tsung. (Original work published in Chinese) Liu, Y. S., Guo, M., & Yuan, X. H. (2006). Study on psychological press of pregnant women and analysis of correlative factors. Modern Nursing, 12(30), 2852Y2854. (Original work published in Chinese) McHorney, C. A., Ware, J. E., Rachel Lu, J. F., & Sherbourne, C. D. (1994). The MOS 36-Item Short-Form Health Survey (SF-36): III. Tests of data quality, scaling assumptions, and reliability across diverse patient groups. Medical Care, 32(1), 40Y66. Messick, S. (1980). Test validity and the ethics of assessment.
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American Psychologist, 35(11), 1012Y1027. doi:10.1037//0003066X.35.11.1012 Mulder, E. J. H., Robles de Medina, P. G., Huizink, A. C., Van den Bergh, B. R. H., Buitelaar, J. K., & Visser, G. H. A. (2002). Prenatal maternal stress: Effects on pregnancy and the unborn child. Early Human Development, 70, 3Y14. doi:10.1016/S03783782(02)00075-0 Munro, B. H. (2005). Statistical methods for health care research (5th ed.). Philadelphia, PA: Lippincott Williams & Wilkins. Netemeyer, R. G., Bearden, W. O., & Sharma, S. (2003). Scaling procedures: Issues and applications. London, UK: Sage. Pett, M. A., Lackey, N. R., & Sullivan, J. J. (2003). Making sense of factor analysis: The use of factor analysis for instrument development in health care research. California, CA: Sage. Polit, D. F., & Beck, C. T. (2011). Nursing research: Generating and assessing evidence for nursing practice (9th ed.). Philadelphia, PA: Lippincott Williams & Wilkins. Ruiz, R. J., & Avant, K. C. (2005). Effects of maternal prenatal stress on infant outcomes: A synthesis of the literature. Advances in Nursing Science, 28(4), 345Y355. Ruiz, R. J., & Fullerton, J. T. (1999). The measurement of stress in pregnancy. Nursing and Health Sciences, 1(1), 19Y25. doi:10.1046/ j.1442-2018.1999.00004.x Van den Bergh, B. R. H., Mulder, E. J. H., Mennes, M., & Glover, V. (2005). Antenatal maternal anxiety and stress and the neurobehavioral development of the fetus and child: links and possible mechanisms: A review. Neuroscience and Biobehavioral Reviews, 29, 237Y258. doi:10.1016/j.neubiorev.2004.10.007 Wang, H. H., Chung, U. L., Chou, P. H., & Chiang, Y. P. (2006). Physical and mental pressure: A survey on pregnant women in Taiwan who originally came from Southeast Asia. Journal of Health Management, 4(1), 89Y101. (Original work published in Chinese) Wang, P. L. (2008). A study of the pregnancy stress perceived by 11 mothers of difficult infants. Journal of Taipei Municipal University of Education, 39(1), 123Y160. (Original work published in Chinese) Winter, J. C. F., Dodou, D., & Wieringa, P. A. (2009). Exploratory factor analysis with small sample sizes. Multivariate Behavioral Research, 44(2), 147Y181. doi:10.1080/00273170902794206
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懷孕壓力量表
VOL. 23, NO. 1, MARCH 2015
懷孕壓力量表之修訂與驗證 陳彰惠 國立成功大學健康照護科學研究所暨護理學系教授
背 景
懷孕是生活壓力事件之一 ，孕期壓力會造成母體荷爾蒙和免疫系統的改變 ，導致孕期 合併症或產後精神障礙 ，且有可能影響胎兒健康。本作者於 1983 年所發表之 30 題「孕 期壓力量表」，是目前全球唯一測量懷孕相關壓力之量表。
目 的
本研究旨在重新思考和修訂「懷孕壓力量表」 ，並驗證更新版本之信度和效度。
方 法
本研究採用橫斷式研究設計 ，依據臨床經驗和專家意見增加新題數 ，編製一份符合社 會現況之 40 題新版「懷孕壓力量表」 。樣本來源為南部地區某一醫學中心之產前門診 ， 共收集有效樣本 300 位孕婦完成問卷填寫 ，以檢定其內部一致性 、再測信度 、建構效 度 、聚合效度和辨別效度。
結 果
新版「懷孕壓力量表」經項目分析和因素分析後 ，由 40 題減為 36 題 ，此 36 題中文版具 有良好的內部一致性（α = .92）和 2 週再測信度（r = .82）。進行因素分析的結果證實其 建構效度 ，萃取出五個因素可解釋 52.17% 的總變異量。本量表與壓力知覺量表和社會 支持量表有顯著相關 ，可顯示其聚合效度和辨別效度。
結 論
36 題新版「懷孕壓力量表」經由驗證後 ，針對測量現代台灣婦女之孕期壓力程度是一份 可信 、有效與實用的量表 ，可作為未來具高度壓力的孕婦介入措施之成效測量工具。 建議將此量表譯成英文 ，並檢定其在西方社會的適用性。
關鍵詞：懷孕壓力、孕期照護、量表發展。
接受刊載：103年2月17日 通訊作者地址：陳彰惠 70101台南市大學路1號 電話：（06）2353535－5846 E-mail: [email protected]
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Revision and Validation of a Scale to Assess Pregnancy Stress Chung-Hey Chen PhD, RN, Professor, Institute of Allied Health Sciences and Department of Nursing, National Cheng Kung University.
ABSTRACT Background: Pregnancy is a potentially stressful event. Prenatal stress alters maternal endocrine and immune systems, has been implicated in the etiology of prenatal complications or postnatal psychiatric disorders, and may adversely affect fetal health. The 30-item Pregnancy Stress Rating Scale (PSRS), initially developed in 1983 by Chen and colleagues, is the only measure to date designed specifically to evaluate prenatal stress. Purpose: The purpose of this study was to reconsider and revise the 30-item PSRS and validate the new PSRS. Methods: A cross-sectional design was used. Adding new items of pregnancy stress generated from clinical experience and expert recommendations resulted in a 40-item revised PSRS that was more reflective of current social conditions. Three hundred pregnant women, recruited from the antenatal clinic of a medical center in southern Taiwan, completed the revised PSRS to assess its internal consistency, testYretest reliability, construct validity, and convergent and discriminate validity. Results: The final 36-item PSRS (PSRS36) was derived by deleting four items with relatively low itemYtotal correlation coefficients or factor loadings. The resultant 36-item scale showed good internal consistency (! = .92) and 2-week testYretest reliability (r = .82). Factor analysis confirmed construct validity and suggested five prenatal stress dimensions, which explained 52.17% of the total variance. Convergent and discriminate validities were indicated by significant correlations among the PSRS36, Perceived Stress Scale, and Interpersonal Support Evaluation List. Conclusions: The PSRS36 is a psychometrically sound and practical tool for nurses and other healthcare providers to assess prenatal stress and to examine intervention protocols in Taiwanese prenatal women. More research is recommended to determine whether the PSRS36 may be used in other racial-ethnic groups.
(Beydoun & Saftlas, 2008). Growing evidence relates prenatal maternal stress to increases in serum levels of corticotrophinreleasing hormone, adrenocorticotropic hormone, and cortisol. Increases in these three hormones activate proinflammatory cytokine (Interleukin 6) production in the expectant mother’s immune system (Coussons-Read, Okun, & Nettles, 2007; Ruiz & Avant, 2005). Maternal stress hormones are also transmitted across the placenta and thus affect the fetal development of the hypothalamicYpituitaryYadrenal axis, limbic system, and the prefrontal cortex (Van den Bergh, Mulder, Mennes, & Glover, 2005). These prenatal stress-related biological changes may lead to unfavorable outcomes in pregnancy such as spontaneous abortion, preterm birth, low birth weight (Hobel, Goldstein, & Barrett, 2008; Mulder et al., 2002), developmental delays (Ruiz & Avant, 2005), temperamental and behavioral problems in toddlers (Gutteling et al., 2005), and postpartum mood disorder (Beydoun & Saftlas, 2008). It is therefore important to have an appropriate instrument to measure women’s prenatal stress. In 1983, Chen and colleagues developed the first Pregnancy Stress Rating Scale (PSRS) to measure a wide range of concerns unique to pregnant women. This 30-item instrument measures the perceptions of respondents to a variety of stressful concerns on a 5-point Likert scale ranging from 0 (definitely no) to 4 (very severe). Chen and colleagues tested the PSRS with 250 Taiwanese subjects in their third trimester of pregnancy (Chen, Yu, & Hwang, 1983). Three categories of psychological stressors were identified through factor analysis: (a) navigating safely through pregnancy, labor, and delivery; (b) identifying with the maternal role; and (c) coping with altered body structure, image, and function. These three factors were then used in further studies (Chen, Chen, & Huang, 1989; Chen, Huang, & Ke, 1991).
KEY WORDS: pregnancy stress, prenatal care, instrument development.
Introduction Pregnancy is a stressful event (Affonso & Mayberry, 1990; Van den Bergh, Mulder, Mennes, & Glover, 2005). Belief in the noxious health effects of prenatal maternal stress has been widespread since the age of Hippocrates, although intensive research in this area did not emerge until the early 1970s
Accepted for publication: February 17, 2014 *Address correspondence to: Chung-Hey Chen, No. 1, University Road, Tainan City 70101, Taiwan, ROC. Tel: +886 (6) 235-3535 ext. 5846; Fax: +886 (6) 237-7550; E-mail: [email protected] Cite this article as: Chen, C. H. (2015). Revision and validation of a scale to assess pregnancy stress. The Journal of Nursing Research, 23(1), 25Y32. doi:10.1097/jnr.0000000000000047
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The PSRS has been widely used in Mandarin-speaking societies to assess stress in pregnant women. Taiwanese investigators Kuo, Lee, Lee, and Liu (2002) found primary stressors for women receiving assisted reproductive techniques (ARTS) to be (in order of eigenvalue) as follows: (a) the health and safety of mother and child, (b) physical figure and activity changes, and (c) and maternal role identification. They found a significantly lower psychological stress response to maternal role identification in the assisted reproductive techniques group than the control group. Wang, Chung, Chou, and Chiang (2006) identified the top three stressors for Southeast Asian immigrant mothers living in Taiwan to be the normalcy, safe delivery, and health of their infants. Wang (2008) used the PSRS to track pregnancy stress in 200 Taiwanese mothers during each trimester and a follow-up infant temperament questionnaire at 4-month postpartum. She found no significant difference in PSRS scores from each trimester between mothers of infants with a difficult temperament and those infants whose temperament was calmer. At least three investigators have used the PSRS in China. For example, Liu, Guo, and Yuan (2006) used the scale on 206 pregnant women in Beijing and found their main stressor to be the concern about the health and safety of the mother and the fetus. The Chinese version of the PSRS was the first scale designed to measure stress unique to the pregnancy experience in Taiwan, including potentially stressful pregnancy-related events and anticipated events during the labor, delivery, and immediate postpartum periods. English-language instruments designed to measure stress include the Perceived Stress Scale (PSS), life events inventory, and perceived stress questionnaire, each of which focus on major life events; the daily hassles scale, which focuses on cumulative minor stressors; and combinations of these instruments (Fliege et al., 2005; Ruiz & Fullerton, 1999). Life event measures use a global definition of stress and thus offer little opportunity to be prescriptive about stressors or develop interventions (Ruiz & Avant, 2005; Ruiz & Fullerton, 1999). Therefore, more definitive measures of prenatal stress are needed to extend our understanding of this issue and suggest effective interventions. Changes in society significantly influence perceived prenatal stressors. The 1983 PSRS, designed to explore prenatal stress in Taiwanese women, thus may need updating to fit today’s social conditions. Significant Taiwanese social changes that a revised scale should consider include (a) the larger percentage of immigrant mothers receiving maternal care in Taiwan (Lee, Chen, & Chen, 2010), (b) comparatively greater concern with body weight management during both prenatal and postnatal periods, (c) the decreased prevalence of extended families, (d) change in venue preference for postpartum care (the traditional practice of ‘‘doing-the-month’’) from the home to privately run postpartum service centers, and (e) the breastfeeding policy promoted by the Taiwan Ministry of Health and Welfare. This study was thus designed to update and revise the Chinese 30-item PSRS to reflect current social conditions and the impact of these conditions on today’s prenatal population in Taiwan. 26
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Methods A cross-sectional study was used to revise the Chinese version of PSRS and test its psychometric properties.
Participants The investigator recruited a convenience sample of 300 prenatal women from the antenatal clinic of a medical center in Tainan, southern Taiwan, over a 6-month period. Inclusion criteria were as follows: (a) over 18 years old, (b) over 17 weeks since last menses, (c) expected to have uncomplicated vaginal deliveries, (d) able to read Chinese, and (e) willing to participate in this study. Pregnant women who had experienced a fetal death or stillbirth were excluded. A sample size of 300 is adequate for factor analysis (Winter, Dodou, & Wieringa, 2009). The institutional review board of the target medical center approved the research protocol.
Measures Demographic data Participant demographic data that were collected included age, educational level, employment status, social class, gravidity, type of pregnancy, baby’s gender, feelings about the baby’s gender, prenatal complications, and marital satisfaction. The Index of Status Position was used to stratify social class (Lin, 1978). The social class of a nuclear family unit was estimated by combining the couple’s information on education and occupation. The Index of Status Position classifies social status into levels 1Y5. In this study, levels 1 and 2 were categorized as upper class, level 3 was categorized as middle class, and levels 4 and 5 were categorized as lower class. Revised pregnancy stress rating scale Chen and colleagues initially developed the 30-item Chinese version of PSRS to measure perceived prenatal stress in mothers in 1983. The preface to the PSRS provided to respondents is as follows: ‘‘The statements listed below describe pregnancy related stressors. You are asked to rate your CURRENT degree of concern, worry, or/and distress about pregnancy-related changes by indicating definitely no, mild, moderate, severe, or very severe in the appropriate column.’’ For this study, a 37-item revised PSRS was drafted that included seven new items (anticipated stressors during labor, delivery, and immediate postpartum) addressing social conditions and concerns/ worries currently prevalent among Taiwanese prenatal mothers. These new items included ‘‘deciding who will help take care of the baby,’’ ‘‘elder children expressing jealousy or dislike of the fetus,’’ ‘‘husband absence during labor,’’ ‘‘doctor attitudes during labor and delivery,’’ ‘‘nurse attitudes during labor and delivery,’’ ‘‘ability to breastfeed successfully,’’ and ‘‘returning to prenatal body shape and weight during the postnatal period.’’ Five experts critiqued the revised PSRS for item clarity and relevance. Two experts were specialists in maternity nursing
Pregnancy Stress Rating Scale
(one senior nursing faculty and one clinical supervisor), and three were obstetricians. Two pregnant women assessed the face validity of the revised scale. On the basis of expert recommendations, several items were reworded, and three new items were added, including ‘‘Adherence to pregnancy taboos is troublesome,’’ ‘‘I worry whether fetal movement is normal,’’ and ‘‘I have diminished sleep quality.’’ These revisions resulted in a revised 40-item instrument. Items were rated on a 5-point Likert scale ranging from 0 (definitely no) to 4 (very severe). The sum total of all item scores provided the prenatal stress score; higher values indicated higher perceived prenatal stress.
Perceived stress scale The 10-item PSS measures current stress caused by the respondent’s perceived diminished capacity to control or cope with life events (Cohen & Williamson, 1988). The PSS was used to determine how closely its measurements paralleled the revised PSRS for the same construct. The Chinese version of PSS had adequate testYretest reliability (r = .81, over a 2-week interval; Chen, Tseng, Wang, & Lee, 1994) and good internal consistency (Cronbach’s ! = .83Y.84; Chang, Chen, & Huang, 2008; Ko, Chang, & Chen, 2010). Internal consistency reliability (Cronbach’s !) was .87 in this study. Interpersonal support evaluation list Social support was measured using the 16-item Interpersonal Support Evaluation List (ISEL; Cohen, Mermelstein, Kamarch, & Hoberman, 1985). The scale measures four types of social support: tangible, appraisal, self-esteem, and belonging. Item scores range from 0 to 3, and higher scores indicate higher perceived social support. The Chinese version of the ISEL Short Form has adequate convergent validity (r = .55 with the Social Support Index), internal consistency (! = .81), and testYretest reliability (r = .77; Chen et al., 1994; Hung, Tsai, Ko, & Chen, 2013). In this study, internal consistency was adequate (! = .85).
Data Analysis Data were analyzed using SPSS for Windows version 17.0 (SPSS, Inc., Chicago, IL, USA). ItemYtotal correlation was conducted to evaluate items for retention in the scale. The criteria for deleting items were itemYtotal correlation of less than .30 (Polit & Beck, 2011). Cronbach’s ! was calculated to analyze the internal consistency reliability, and Pearson productYmoment correlation coefficient was used to demonstrate evidence of testYretest reliability. The construct validity for the new PSRS was evaluated using exploratory factor analysis. The following criteria were used: (a) the factor loading was greater than .30, (b) each dimension had an eigenvalue of 1 or more followed by a scree test, and (c) at least three items in each factor (Munro, 2005; Netemeyer, Bearden, & Sharma, 2003; Pett, Lackey, & Sullivan, 2003). The scale score distribution and its ceiling effect and floor effect were examined (McHorney, Ware, Rachel Lu, & Sherbourne, 1994). Pearson’s correlation coefficient was employed to test the convergent and discriminate validity. All results were considered significant at p G .05.
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Results Three hundred Taiwanese prenatal women completed the revised PSRS. The average age of participants was 31.6 T 4.1 years (range = 18Y44 years); most (n = 255, 85%) held a junior college degree or higher, 68.3% held full-time employment, slightly more than half (n = 155, 51.7%) were of high socioeconomic status, and just over one third (n = 110, 36.7%) were middle class. All (n = 300, 100%) were married, and most (n = 221, 73.7%) expressed satisfaction with married life. Table 1 shows the participants’ demographic characteristics. ItemYtotal correlations for the 40-item revised PSRS ranged from .13 to .68. Two items, ‘‘frequent uterus contractions and tightening’’ and ‘‘older children express jealousy or dislike of the fetus,’’ were removed as the itemYtotal correlation coefficients for these two fell below the threshold of .30 (Chiou, 2010). An exploratory factor analysis of the revised 38-item PSRS using an eigenvalue of 1.00 or greater as the cutoff point for factor extraction combined with a scree test was then conducted (Pett et al., 2003). This analysis indicated that a fivedimension model in which each dimension retains three or more items with salient loadings of more than .30 would be TABLE 1.
Participant Demographic Characteristics (N = 300) Variable
n
%
Education eSenior high school 9Senior high school
45 255
15.0 85.0
Occupation Employed Housewife
205 95
68.3 31.7
Socioeconomic status High Middle Low
155 110 35
51.7 36.7 11.6
Type of pregnancy Planned Unplanned
205 95
68.3 31.7
Baby gender Boy Girl Twin or unknown
126 126 48
42.0 42.0 16.0
Feelings about the baby’s gender Meets preference Does not meet preference No opinion
105 32 163
35.0 10.7 54.3
Prenatal complications No Yes
278 22
92.7 7.3
Marital satisfaction Satisfied Acceptable Dissatisfied
221 78 1
73.7 26.0 0.3
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best (Netemeyer et al., 2003). Two items were subsequently removed (‘‘I worry having a child will force me to stop working’’ and ‘‘Having a child will decrease my interest in social contacts and activities’’) because factor loadings fell below the threshold of .30 in all dimensions. The revised 36-item PSRS (PSRS36) was then subjected to a forced five-factor principal axis analysis followed by a Varimax rotation. Correlation matrix quality was high, as measured using KaiserYMeyerYOlkin (.88). A significant Bartlett test of sphericity (Chi-square = 5594.08, p G .001) justified the use of factor analysis as a
Chung-Hey Chen
dimension-reducing procedure. Table 2 shows factorial solutions (eigenvalues ranged from 1.56 to 10.28) and rotated loadings. Assignment of items to factors was mutually exclusive. The five-factor solution accounted for 52.17% of variance, with each factor accounting, respectively, for 28.54%, 7.33%, 6.57%, 5.39%, and 4.34% of the total variance for prenatal stress variables. The summed scores for the five factors formed the global PSRS36 score (range = 0Y144). As shown in Table , factor analysis was used to confirm the construct validity of the PSRS. Results supported the five
TABLE 2.
Principal Axis Factor Analysis of Pregnancy Stress Rating Scale Item Degree of Concern, Worry, or/and Distress
ITC Factor Loading
Factor 1: Stress from seeking safe passage for mother and child through pregnancy, labor, and delivery 1. Abnormal or difficult birth 2. Safe labor and delivery for my sake 3. Safe delivery for my baby’s sake 4. Doctor may not arrive on time at delivery 5. Premature labor 6. Doctor attitudes during labor and delivery 7. Nurse attitudes during labor and delivery 8. Husband’s absence during labor 9. Unbearable labor pain
.653 .669 .665 .637 .591 .709 .725 .566 .611
.784 .746 .744 .743 .738 .722 .707 .603 .519
Factor 2: Stress from baby care and changing family relationships 1. Breast or bottle feed my baby 2. Ability to breastfeed successfully 3. Ability to raise my baby successfully 4. Naming my baby 5. Sexual activity during pregnancy 6. Loss of free time after birth 7. Acceptance of the child by significant others 8. Increased financial burden 9. Support from family members or husband
.628 .640 .669 .514 .506 .494 .321 .530 .352
.695 .676 .618 .617 .565 .506 .442 .416 .361
Factor 3: Stress from maternal role identification 1. Baby’s appearance 2. Baby’s birth weight 3. Baby’s gender 4. Baby’s health 5. Concern about status of fetal movement 6. Adhering to traditional pregnancy mores 7. Maternal behavior influencing the fetus 8. Preparation of clothes and newborn supplies for baby
.496 .535 .434 .593 .588 .391 .427 .526
.671 .647 .560 .549 .548 .516 .501 .469
Factor 4: Stress from social support seeking 1. Finding a qualified baby-sitter 2. Deciding who will help take care of the baby 3. Choosing a place to ‘‘do-the-month’’ 4. Arranging for someone to handle housework during labor
.313 .449 .524 .465
.798 .789 .758 .692
Factor 5: Stress from altered physical appearance and function 1. Altered body shape during pregnancy 2. Controlling weight during pregnancy 3. Mobility difficulties due to altered body shape 4. Returning to prenatal body shape and weight during postnatal period 5. Dark brown areas appearing on the skin 6. Sleep quality
.400 .356 .332 .566 .409 .454
.740 .708 .666 .563 .554 .339
Note. ITC = itemYtotal correlation.
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Pregnancy Stress Rating Scale
factors as appropriate dimensions of prenatal stress: Factor 1, stress from seeking safe passage for mother and child through pregnancy, labor, and delivery (e.g., worry about ‘‘abnormal or difficult birth,’’ ‘‘safe labor and delivery for my sake,’’ ‘‘safe delivery for my baby’s sake’’); Factor 2, stress from baby care and changing family relationships (e.g., worry about ‘‘breast or bottle feed my baby,’’ ‘‘ability to breastfeed successfully,’’ ‘‘ability to raise my baby successfully’’); Factor 3, stress from maternal role identification (e.g., worry about ‘‘baby’s appearance,’’ ‘‘baby’s birth weight,’’ ‘‘baby’s gender’’); Factor 4, stress from social support seeking (e.g., worry about ‘‘finding a qualified baby-sitter,’’ ‘‘deciding who will help take care of the baby,’’ ‘‘choosing a place to do-the-month’’); Factor 5, stress from altered physical appearance and function (e.g., worry about ‘‘altered body shape during pregnancy,’’ ‘‘controlling weight during pregnancy,’’ ‘‘mobility difficulties due to altered body shape’’). The 300 pregnant women earned an average PSRS36 score of 53.96 T 21.04 (range = 10Y111). Moreover, 0.3% of the sample achieved the lowest score, and 1% achieved the highest score; the PSRS36 had trivial ceiling and floor effects. The alpha for each subscale of the PSRS36 was adequate, ranging from .73 to .91 (DeVellis, 2003). The PSRS36 had good internal consistency (Cronbach’s ! = .92), and 2-week testYretest reliability was .82 (n = 30), indicating stable PSRS36 responses. PSRS36 scores were positively correlated with PSS (r = .40, p G .001) and negatively correlated with ISEL (r = j.27, p G .001), supporting convergent and discriminate validities.
Discussion The original 1983 PSRS (Chen et al., 1983) was revised, and its dimensional structure was tested on a sample of prenatal women in Taiwan. The researcher expanded the questionnaire from 30 to 36 items. The PSRS36 achieved satisfactory psychometric characteristics in terms of reliability, construct validity, and convergent and discriminate validity. The PSRS36 addresses the five distinct prenatal stress dimensions of seeking safe passage for mother and child, baby care and changing family relationships, maternal role identification, social support seeking, and altered physical appearance and functions. The acceptable alpha coefficients (.73Y.91) for the five subscales indicated that five strong factors were formed in PSRS36, thus providing evidence of internal consistency and reliability and providing initial evidence of construct validity for a developing scale (Munro, 2005). The second and fourth dimensions were new additions that were not part of the original threedimension PSRS. The first dimension considers maternal safety in terms of physical well-being and the survival of both mother and child. The second dimension relates to anticipatory competence with regard to mothering, acceptance of the child by significant others, bonding with the child, and contemplations on the changing relationships between mother and child and other family members. The third dimension addresses the prenatal mother’s concerns about her baby’s appearance, gender, and
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well-being and the inherent conflicts that arise between fantasized ‘‘perfect’’ outcomes and dreaded ‘‘problem’’ outcomes. The fourth dimension addresses ‘‘nesting behavior’’ and the prenatal mother’s concerns related to providing a good home for her unborn child. The fifth dimension addresses the prenatal mother’s concerns related to altered physical appearance and functions and perceived loss of control over body functions. Considerations of the consequential basis of instrument interpretation cannot ignore the influence of social values and theoretical interpretations (Messick, 1980). Four items significantly associated with Taiwan-specific sociocultural systems were concentrated in the three dimensions of baby care and changing family relationships (Factor 2), maternal role identification (Factor 3), and social support seeking (Factor 4). These four items were ‘‘naming my baby,’’ ‘‘maternal behavior influencing the fetus,’’ ‘‘adhering to traditional pregnancy mores,’’ and ‘‘choosing a place to ‘do-the-month.’’’ An infant’s name, together with the time of birth, is believed to be crucial to ensuring her or his good fortune in life (Chang & Chen, 2005; Hung, 2006). Choosing an appropriate name for an infant before she or he is born is an activity that usually involves the extended family and potentially conflicting opinions. ‘‘Naming my baby’’ was thus included as a prenatal stress scale item on the PSRS36. Cultural rituals and social taboos heavily influence pregnancy and childbirth behavior (Lee et al., 2009), and these events may cause stress to women. A Hong Kong study found that all prenatal women surveyed followed at least one or more traditional prescription/proscription during pregnancy to avoid pregnancy loss or mishap and that about one quarter felt they had lost some freedom, were unhappy about such restrictions, and faced stress from intergenerational conflicts in this regard (Lee et al., 2009). Similarly, although many women in Taiwan are uncertain about the efficacy of these traditional mores, most choose to follow at least some as precautions against miscarriage, birth defects, and other imperfections (Chou, 2002; Lee et al., 2009) as well as to attract good fortune. It is observed that some prenatal women in Taiwan still adhere to ‘‘prenatal education’’ behaviors that include actively adjusting mind and mood to enhance embryo health and passively obeying dietary and behavioral taboos during pregnancy to nurture a ‘‘good’’ baby. The various prescriptions and proscriptions required when following these practices may intensify prenatal stress (Geller, 2004). Therefore, ‘‘maternal behavior influencing the fetus’’ and ‘‘adhering to traditional pregnancy mores’’ were two prenatal stress items in the PSRS36. Pregnant women may experience anticipated or floating stress about the future situation during the ‘‘doing-the-month’’ postpartum period. In the month after childbirth, Taiwanese mothers typically receive extra attention and support from the family and are allowed to rest. Their mothers, mothersin-law, sisters, and other female relatives are regarded as natural helpers during the ‘‘doing-the-month’’ postpartum period (Chen & Liu, 1995). Although living with her parents-in-law during this period is the traditional norm, care provided in 29
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these close quarters may exacerbate the often sensitive and easily conflictive relationship between the new mother and her mother-in-law (Chen & Liu, 1995). Although offering assistance during difficult times, the mother-in-law may also express criticism or disapproval of the postpartum behavior of her daughter-in-law, particularly in relation to infant care (Chen & Liu, 1995). Regarding the place for ‘‘doing the month,’’ postpartum service centers are an emerging institution in Taiwan offering an alternative to new mothers. Their popularity in recent years has grown because of the increased prevalence of nuclear families, decline of extended family households, and decreased availability of family support. Prenatal women in Taiwan thus worry about identifying a helper for their postpartum month and finding a suitable place to ‘‘do-the-month.’’ ‘‘Choosing a place to ‘do-the-month’’’ was thus included as a prenatal stress scale item on the PSRS36. The limitations of this study are that the revised PSRS36 was tested on prenatal women older than 18 years who were in the second or third trimester and who anticipated uncomplicated vaginal deliveries. Therefore, the revised PSRS36 may not be generalized to populations of prenatal women who do not meet these criteria. Despite this limitation, the results of this study highlight the significance of PSRS36 in providing a more appropriate scale to measure the unique pregnancy stress faced by expectant mothers in Taiwan. The psychometric qualities of the PSRS36 have important clinical and research implications. Nurses and other healthcare providers should assess psychological stress in prenatal women and provide care appropriate to the specific stressors involved to ensure the well-being of both mother and fetus through pregnancy, labor, and delivery. Accurately assessing stress in prenatal women may be useful not only to help these women cope with stress but also to guide the development of prenatal stress interventions such as stress prevention/resilience-building programs and support groups. Because some items on the PSRS36 are associated with Taiwanese cultural rituals and social taboos, further research is needed to assess the applicability of this scale to other ethnic groups and whether modification is necessary for use outside Taiwan and Taiwanese communities.
Acknowledgments This study was supported by a grant from the National Science Council of Taiwan. I am grateful to Dr. Carol Shieh, Associate Professor of Indiana University (United States), for ChineseY English translation validity check; to Professor Graeme Smith of Edinburgh Napier University (United Kingdom) for his editorial assistance with the PSRS36; and to the staff and the pregnant women who participated in the study.
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American Psychologist, 35(11), 1012Y1027. doi:10.1037//0003066X.35.11.1012 Mulder, E. J. H., Robles de Medina, P. G., Huizink, A. C., Van den Bergh, B. R. H., Buitelaar, J. K., & Visser, G. H. A. (2002). Prenatal maternal stress: Effects on pregnancy and the unborn child. Early Human Development, 70, 3Y14. doi:10.1016/S03783782(02)00075-0 Munro, B. H. (2005). Statistical methods for health care research (5th ed.). Philadelphia, PA: Lippincott Williams & Wilkins. Netemeyer, R. G., Bearden, W. O., & Sharma, S. (2003). Scaling procedures: Issues and applications. London, UK: Sage. Pett, M. A., Lackey, N. R., & Sullivan, J. J. (2003). Making sense of factor analysis: The use of factor analysis for instrument development in health care research. California, CA: Sage. Polit, D. F., & Beck, C. T. (2011). Nursing research: Generating and assessing evidence for nursing practice (9th ed.). Philadelphia, PA: Lippincott Williams & Wilkins. Ruiz, R. J., & Avant, K. C. (2005). Effects of maternal prenatal stress on infant outcomes: A synthesis of the literature. Advances in Nursing Science, 28(4), 345Y355. Ruiz, R. J., & Fullerton, J. T. (1999). The measurement of stress in pregnancy. Nursing and Health Sciences, 1(1), 19Y25. doi:10.1046/ j.1442-2018.1999.00004.x Van den Bergh, B. R. H., Mulder, E. J. H., Mennes, M., & Glover, V. (2005). Antenatal maternal anxiety and stress and the neurobehavioral development of the fetus and child: links and possible mechanisms: A review. Neuroscience and Biobehavioral Reviews, 29, 237Y258. doi:10.1016/j.neubiorev.2004.10.007 Wang, H. H., Chung, U. L., Chou, P. H., & Chiang, Y. P. (2006). Physical and mental pressure: A survey on pregnant women in Taiwan who originally came from Southeast Asia. Journal of Health Management, 4(1), 89Y101. (Original work published in Chinese) Wang, P. L. (2008). A study of the pregnancy stress perceived by 11 mothers of difficult infants. Journal of Taipei Municipal University of Education, 39(1), 123Y160. (Original work published in Chinese) Winter, J. C. F., Dodou, D., & Wieringa, P. A. (2009). Exploratory factor analysis with small sample sizes. Multivariate Behavioral Research, 44(2), 147Y181. doi:10.1080/00273170902794206
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懷孕壓力量表
VOL. 23, NO. 1, MARCH 2015
懷孕壓力量表之修訂與驗證 陳彰惠 國立成功大學健康照護科學研究所暨護理學系教授
背 景
懷孕是生活壓力事件之一 ，孕期壓力會造成母體荷爾蒙和免疫系統的改變 ，導致孕期 合併症或產後精神障礙 ，且有可能影響胎兒健康。本作者於 1983 年所發表之 30 題「孕 期壓力量表」，是目前全球唯一測量懷孕相關壓力之量表。
目 的
本研究旨在重新思考和修訂「懷孕壓力量表」 ，並驗證更新版本之信度和效度。
方 法
本研究採用橫斷式研究設計 ，依據臨床經驗和專家意見增加新題數 ，編製一份符合社 會現況之 40 題新版「懷孕壓力量表」 。樣本來源為南部地區某一醫學中心之產前門診 ， 共收集有效樣本 300 位孕婦完成問卷填寫 ，以檢定其內部一致性 、再測信度 、建構效 度 、聚合效度和辨別效度。
結 果
新版「懷孕壓力量表」經項目分析和因素分析後 ，由 40 題減為 36 題 ，此 36 題中文版具 有良好的內部一致性（α = .92）和 2 週再測信度（r = .82）。進行因素分析的結果證實其 建構效度 ，萃取出五個因素可解釋 52.17% 的總變異量。本量表與壓力知覺量表和社會 支持量表有顯著相關 ，可顯示其聚合效度和辨別效度。
結 論
36 題新版「懷孕壓力量表」經由驗證後 ，針對測量現代台灣婦女之孕期壓力程度是一份 可信 、有效與實用的量表 ，可作為未來具高度壓力的孕婦介入措施之成效測量工具。 建議將此量表譯成英文 ，並檢定其在西方社會的適用性。
關鍵詞：懷孕壓力、孕期照護、量表發展。
接受刊載：103年2月17日 通訊作者地址：陳彰惠 70101台南市大學路1號 電話：（06）2353535－5846 E-mail: [email protected]
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