Primiparous Outcomes and Future Pregnancy Health Behaviors Felix A. Okah, MD, MS; Jinwen Cai, MD Objective: To examine the impact of repeat, G2, and outcomes of first, G1, (previous livebirth, PLB, or stillbirth, PSB) pregnancies on health-compromising behaviors (HCB). Methods: Retrospective cohort study of 137,374 pregnancies in Kansas City, MO, 1990 through 2009, using birth certificate database. Results: Overall HCB rate was 17% and increased with G2 and PSB (G1=12% v G2-PLB=21% v G2-PSB=29%, p < .001). Compared to G2-PLB, the odds of HCB increased for G2-
P
regnancy provides a unique opportunity for interventions in a woman’s overall health and education about maternal, fetal, and pediatric health effects of her health behaviors.1 Utilizing this window of educational opportunities is important because studies show that with increasing numbers of live births a woman is less likely to practice health-promoting behaviors and more likely to engage in health-compromising behaviors during pregnancy.2-5 One report showed that women with phenylketonuria are less compliant with dietary restrictions in pregnancies that follow a successful live birth.2 Similarly, others have demonstrated lower levels of physical activity and exercise, fewer and later attendance to prenatal care, and higher levels of alcohol consumption as a function of increasing numbers of pregnancies when compared to the initial ones (primiparous).3-5 The underlying reasons for these trends are unclear, and suggest that women may become increasingly less concerned about the health consequences of their behaviors following a previous live birth. The observation may also reflect optimism for a positive outcome among those who have had a previous pregnancy. Smoking, currently the most widely practiced health-compromising behavior during pregnancy, is associated with significant perinatal morbidity
Felix A. Okah, Professor, Children’s Mercy Hospitals and Clinics, University of Missouri Kansas City School of Medicine, Kansas City, MO. Jinwen Cai, Statistician, Health Department, Kansas City, MO. Correspondence Dr Okah; [email protected]
316
PSB (OR=1.42; 95%CI 1.10, 1.82) and decreased for G1 (0.54; 0.52, 0.56). Conclusion: Women are more likely to engage in HCB during their second pregnancy, especially those who lose their first pregnancy. This finding is evidence for promoting effective inter-conception health care at post-partum and primary care visits. Key words: health behaviors, parity, pregnancy Am J Health Behav. 2014;38(2)316-320 DOI: http://dx.doi.org/10.5993/AJHB.38.2.17
and mortality.6 Equally important are the behavioral associations; smokers are more likely than others to engage in multiple other health-compromising behaviors such as alcohol consumption and illicit drug use, both of which compromise the fetus, mother-child interaction, and subsequent infant growth and development.7,8 Therefore, it is important to understand which factors are associated with the trend towards less healthy behaviors following a successful live birth. It is possible that women who are pregnant for the first time initially exercise caution that they dispensed with following a live birth outcome for them and others, especially if they or those others engaged in health compromising behaviors. We speculate that a “good” outcome may diminish fear of adverse consequences from these behaviors during a subsequent pregnancy. If true, concern for and the outcome of the first pregnancy (primigravida or G1) rather than the fact of a repeat pregnancy (gravida 2 or G2) may be the determining factor for a woman’s initial and subsequent pregnancy health behaviors. To clarify the role of primiparous (first birth) outcomes, we conducted a retrospective cohort study of only women with first (gravida 1 or G1) and second pregnancies (gravida 2 or G2) who had a live (G2- PLB) or stillbirth (G2-PSB) to test the hypothesis that G1 (first-pregnancy) and G2-PSB (second pregnancy, first-pregnancy lost) are less likely than G2-PLB (second pregnancy, first-pregnancy live birth) to engage in health-compromising behaviors. METHODS This is a retrospective cohort study of health-
Okah & Cai
Table 1 Demographic and Behavioral Characteristics of 137,374 Pregnancies by Gravidity and Outcome of a Previous Pregnancy 1990 – 2009, Kansas City, MO Variables
All
Ga1
G2- PSBb
G2-PLBc
N = 137,374
48,743
577
88,054
12y
58126 (44%)
46%
38%
42%
White
63874 (47%)
51%
31%
44%
Black
52125 (38%)
34%
57%
40%
Hispanic
15574 (11%)
11%
7%
12%
Others
5774 (4%)
4%
5%
4%
Married
70302 (51%)
47%
40%
54%
Single
67001 (49%)
53%
60%
46%
Inadequate
17915 (14%)
10%
28%
17%
Intermediate
23611 (19%)
18%
13%
20%
Adequate
82693 (67%)
72%
59%
54%
23946 (17%)
12%
29%
21%
p
Age/Education, years (y) < .001
Race/Ethnicity < .001
Marital Status < .001
Prenatal Care < .001
Health Compromising Behaviors Yes
< .001
Note. a = gravida; b = previous stillbirth; c = previous live birth
compromising behaviors during 137,374 pregnancies after 20 weeks of gestation in Kansas City, MO, from January 1, 1990, through December 31, 2009. We obtained the data from computer files of vital statistics registration birth certificates containing information on the women’s physical, medical (including obstetric), demographics, and health-behavior characteristics. Complete information was abstracted on variables that have been shown previously by others to be associated with health compromising behaviors such as the woman’s age, educational attainment (12 years), marital status (single vs married), race/ethnicity (White vs Black vs Hispanic vs “Others”).9 The “Others” category consisted of Asians, Native American, and unidentified race). Other variables included prenatal care (Inadequate vs Intermediate vs Adequate),10 number of pregnancies (G1 vs G2), and outcomes of first pregnancy among gravida-2, live (PLB) vs stillbirth (PSB). Women’s age and educational attainment were combined into a composite variable because of the correlation of age with years of education. The outcome of interest, health-compromising be-
haviors, was a composite variable defined as engaging in tobacco or alcohol or drug use during pregnancy. Analyses were conducted using SPSS version 18 (IBM ® SPSS, IBM, Armonk, NY). Categorical variables were measured in percentages and compared by chi-square tests. Additional analyses included backward, step-wise (conditional) multivariable logistic regression with “health-compromising behaviors” as the outcome variable and the other variables as independent variables. Statistical significance for all analyses was p < .05.
Am J Health Behav.™ 2014;38(2):316-320
DOI:
RESULTS The cohort consisted of 137,374 pregnancies and the demographic and health-behavior characteristics by numbers of pregnancies and first-pregnancy outcomes (G-1, G-2-PSB, and G-2-PLB) are shown in Table 1. The rate of missing information on the individual variables of interest was 8% to 17%. Compared to the G-2 women, G-1 women were more likely to be teenagers, better educated adults, and to have received adequate prenatal care. Grav-
http://dx.doi.org/10.5993/AJHB.38.2.17
317
Primiparous Outcomes and Future Pregnancy Health Behaviors
Table 2 Model Predicting Health-Compromising Behaviors for 137,374 Pregnancies, 1990 – 2009, Kansas City, MO Variables in model
Adjusted odds ratio
(95% CI)
Gravity/Previous birth – Gravida 2- PLBa
1.00
Reference
Gravida 1
0.54
0.52, 0.56
Gravida 2– PSB
1.42
1.10, 1.82
Age/Education, (years, y) - >20 y/>12y
1.00
Reference
P
regnancy provides a unique opportunity for interventions in a woman’s overall health and education about maternal, fetal, and pediatric health effects of her health behaviors.1 Utilizing this window of educational opportunities is important because studies show that with increasing numbers of live births a woman is less likely to practice health-promoting behaviors and more likely to engage in health-compromising behaviors during pregnancy.2-5 One report showed that women with phenylketonuria are less compliant with dietary restrictions in pregnancies that follow a successful live birth.2 Similarly, others have demonstrated lower levels of physical activity and exercise, fewer and later attendance to prenatal care, and higher levels of alcohol consumption as a function of increasing numbers of pregnancies when compared to the initial ones (primiparous).3-5 The underlying reasons for these trends are unclear, and suggest that women may become increasingly less concerned about the health consequences of their behaviors following a previous live birth. The observation may also reflect optimism for a positive outcome among those who have had a previous pregnancy. Smoking, currently the most widely practiced health-compromising behavior during pregnancy, is associated with significant perinatal morbidity
Felix A. Okah, Professor, Children’s Mercy Hospitals and Clinics, University of Missouri Kansas City School of Medicine, Kansas City, MO. Jinwen Cai, Statistician, Health Department, Kansas City, MO. Correspondence Dr Okah; [email protected]
316
PSB (OR=1.42; 95%CI 1.10, 1.82) and decreased for G1 (0.54; 0.52, 0.56). Conclusion: Women are more likely to engage in HCB during their second pregnancy, especially those who lose their first pregnancy. This finding is evidence for promoting effective inter-conception health care at post-partum and primary care visits. Key words: health behaviors, parity, pregnancy Am J Health Behav. 2014;38(2)316-320 DOI: http://dx.doi.org/10.5993/AJHB.38.2.17
and mortality.6 Equally important are the behavioral associations; smokers are more likely than others to engage in multiple other health-compromising behaviors such as alcohol consumption and illicit drug use, both of which compromise the fetus, mother-child interaction, and subsequent infant growth and development.7,8 Therefore, it is important to understand which factors are associated with the trend towards less healthy behaviors following a successful live birth. It is possible that women who are pregnant for the first time initially exercise caution that they dispensed with following a live birth outcome for them and others, especially if they or those others engaged in health compromising behaviors. We speculate that a “good” outcome may diminish fear of adverse consequences from these behaviors during a subsequent pregnancy. If true, concern for and the outcome of the first pregnancy (primigravida or G1) rather than the fact of a repeat pregnancy (gravida 2 or G2) may be the determining factor for a woman’s initial and subsequent pregnancy health behaviors. To clarify the role of primiparous (first birth) outcomes, we conducted a retrospective cohort study of only women with first (gravida 1 or G1) and second pregnancies (gravida 2 or G2) who had a live (G2- PLB) or stillbirth (G2-PSB) to test the hypothesis that G1 (first-pregnancy) and G2-PSB (second pregnancy, first-pregnancy lost) are less likely than G2-PLB (second pregnancy, first-pregnancy live birth) to engage in health-compromising behaviors. METHODS This is a retrospective cohort study of health-
Okah & Cai
Table 1 Demographic and Behavioral Characteristics of 137,374 Pregnancies by Gravidity and Outcome of a Previous Pregnancy 1990 – 2009, Kansas City, MO Variables
All
Ga1
G2- PSBb
G2-PLBc
N = 137,374
48,743
577
88,054
12y
58126 (44%)
46%
38%
42%
White
63874 (47%)
51%
31%
44%
Black
52125 (38%)
34%
57%
40%
Hispanic
15574 (11%)
11%
7%
12%
Others
5774 (4%)
4%
5%
4%
Married
70302 (51%)
47%
40%
54%
Single
67001 (49%)
53%
60%
46%
Inadequate
17915 (14%)
10%
28%
17%
Intermediate
23611 (19%)
18%
13%
20%
Adequate
82693 (67%)
72%
59%
54%
23946 (17%)
12%
29%
21%
p
Age/Education, years (y) < .001
Race/Ethnicity < .001
Marital Status < .001
Prenatal Care < .001
Health Compromising Behaviors Yes
< .001
Note. a = gravida; b = previous stillbirth; c = previous live birth
compromising behaviors during 137,374 pregnancies after 20 weeks of gestation in Kansas City, MO, from January 1, 1990, through December 31, 2009. We obtained the data from computer files of vital statistics registration birth certificates containing information on the women’s physical, medical (including obstetric), demographics, and health-behavior characteristics. Complete information was abstracted on variables that have been shown previously by others to be associated with health compromising behaviors such as the woman’s age, educational attainment (12 years), marital status (single vs married), race/ethnicity (White vs Black vs Hispanic vs “Others”).9 The “Others” category consisted of Asians, Native American, and unidentified race). Other variables included prenatal care (Inadequate vs Intermediate vs Adequate),10 number of pregnancies (G1 vs G2), and outcomes of first pregnancy among gravida-2, live (PLB) vs stillbirth (PSB). Women’s age and educational attainment were combined into a composite variable because of the correlation of age with years of education. The outcome of interest, health-compromising be-
haviors, was a composite variable defined as engaging in tobacco or alcohol or drug use during pregnancy. Analyses were conducted using SPSS version 18 (IBM ® SPSS, IBM, Armonk, NY). Categorical variables were measured in percentages and compared by chi-square tests. Additional analyses included backward, step-wise (conditional) multivariable logistic regression with “health-compromising behaviors” as the outcome variable and the other variables as independent variables. Statistical significance for all analyses was p < .05.
Am J Health Behav.™ 2014;38(2):316-320
DOI:
RESULTS The cohort consisted of 137,374 pregnancies and the demographic and health-behavior characteristics by numbers of pregnancies and first-pregnancy outcomes (G-1, G-2-PSB, and G-2-PLB) are shown in Table 1. The rate of missing information on the individual variables of interest was 8% to 17%. Compared to the G-2 women, G-1 women were more likely to be teenagers, better educated adults, and to have received adequate prenatal care. Grav-
http://dx.doi.org/10.5993/AJHB.38.2.17
317
Primiparous Outcomes and Future Pregnancy Health Behaviors
Table 2 Model Predicting Health-Compromising Behaviors for 137,374 Pregnancies, 1990 – 2009, Kansas City, MO Variables in model
Adjusted odds ratio
(95% CI)
Gravity/Previous birth – Gravida 2- PLBa
1.00
Reference
Gravida 1
0.54
0.52, 0.56
Gravida 2– PSB
1.42
1.10, 1.82
Age/Education, (years, y) - >20 y/>12y
1.00
Reference
