HHS Public Access Author manuscript Author Manuscript
J Sports Med Phys Fitness. Author manuscript; available in PMC 2017 May 01. Published in final edited form as: J Sports Med Phys Fitness. 2017 May ; 57(5): 652–659. doi:10.23736/S0022-4707.17.06222-3.
Impact of physical activity during pregnancy on obstetric outcomes in obese women Rachel A. Tinius, PhD, ACSM-EP-C1, Alison G. Cahill, MD, MSCI2, and W. Todd Cade, PT, PhD1 1Program
in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri
Author Manuscript
2Department
of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis,
Missouri
Abstract Aim—Maternal obesity is associated with complications and adverse outcomes during the labor and delivery process. In pregnant women with a healthy body weight, maternal physical activity during pregnancy is associated with better obstetric outcomes; however, the effect of maternal physical activity during pregnancy on obstetric outcomes in obese women is not known. The purpose of the study was to determine the influence of self-reported physical activity levels on obstetric outcomes in pregnant obese women.
Author Manuscript
Methods—A retrospective chart review was performed on 48 active obese women and 48 inactive obese women (N=96) who received prenatal care and delivered at the medical center during the past five years. Obstetric and neonatal outcomes were compared between the active and inactive groups. Results—Obese women who were active during pregnancy spent less total time in labor (13.4 hours vs. 19.2 hours, p=0.048) and were less likely to request an epidural (92% vs. 100%, p=0.04). When stratified by parity, active multiparous women spent significantly less total time in labor compared to inactive multiparous (6.2 hours vs. 16.7 hours, p=0.018). There were no statistical differences between groups in rates of cesarean deliveries or neonatal outcomes. Conclusion—Maternal physical activity during pregnancy appears to improve obstetric outcomes in obese women, and this improvement may be more pronounced among multiparous women. Our finding is of particular importance as pregnant obese women are at higher risk for adverse and delivery outcomes.
Author Manuscript
Keywords exercise; cesarean delivery; obesity; epidural
Corresponding author: Rachel A. Tinius, PhD, ACSM-EP-C, School of Kinesiology, Recreation, and Sport, Western Kentucky University, 1906 College Heights Blvd, #11089, Bowling Green, KY 42101, Phone: 270-745-5026, Fax: 314-286-1410, [email protected]. Conflicts of Interest: The authors have no conflicts of interest to disclose.
Tinius et al.
Page 2
Author Manuscript
1. Introduction The medical and economic burden of obesity is a major public health concern. The prevalence of maternal obesity has dramatically increased with one in three women entering pregnancy obese1. Maternal obesity has been associated with a wide array of adverse maternal and neonatal outcomes2 including elevated risk for complications during the labor and delivery process including slower progression of labor, labor dysfunction, and medically necessary cesarean deliveries3,4.
Author Manuscript
Labor complications in obesity include increased total duration of labor5 and slower progression of the early part of the first stage of labor3,6,7. Prolonged time in labor increases the risk for a number of unfavorable outcomes such as operative deliveries, infections, and adverse neonatal outcomes8–10. Maternal obesity has also been associated with active labor dysfunction including arrest of dilation and fetal distress11, both of which contribute to the elevated rate of cesarean deliveries among obese women3,4. In the United States, the rate of cesarean deliveries dramatically rose by 53% from 1996 to 2007, reaching 32% of all deliveries12. The public health impact of excess cesarean deliveries is substantial as cesarean deliveries are expensive and increase the risk for other morbidities such as severe bleeding, infections, painful scarring, blood clots, bowel obstructions, readmissions to the hospital, and longer-lasting pain4. With maternal obesity significantly elevating risk for cesarean deliveries, identification of methods to reduce the number of cesarean deliveries and improve the labor and delivery process for obese women is critical13.
Author Manuscript
In normal-weight women, regular physical activity during pregnancy has been shown to lower the incidence of cesarean deliveries14–17. Similarly, maternal physical activity during pregnancy in normal-weight women is associated with shorter active labors14,16. However, the influence of physical activity on the labor and delivery process and obstetric outcomes in women with pre-pregnancy obesity is not known. Therefore, the purpose of the study was to
examine obstetric outcomes in pregnant obese women who self-reported being physically active during pregnancy versus pregnant obese women who did not. We hypothesized that maternal physical activity during pregnancy would reduce occurrence rate of cesarean sections in pregnant obese women. We secondarily hypothesized that physically active obese women would spend less total time in labor, less time pushing, and would have neonates with higher Apgar scores, healthier birth weights, and less incidence of neonatal complications.
Author Manuscript
2. Materials and Methods 2.1 Study procedures A retrospective chart review was performed on women who received prenatal care at the Washington University School of Medicine’s Women’s Health Center between May 2009 and May 2014. All women treated at this clinic had private insurance, thus, it was considered a moderate-to-high income clinic. The patient’s age, weight, height, body mass index, race, parity, delivery history, gestational weight gain, and pregnancy complications
J Sports Med Phys Fitness. Author manuscript; available in PMC 2017 May 01.
Tinius et al.
Page 3
Author Manuscript
were obtained from their prenatal charts. Pre-pregnancy body mass index (BMI) was determined by weight and height at their first prenatal appointment- typically between eight and nine weeks gestation. If a patient presented for care later than nine weeks gestation, prepregnancy weight was based on self-report. Physical activity information was gathered from health history questionnaires distributed by the clinic at initiation of prenatal care. Selfreported physical activity information was confirmed via personal telephone calls (at which time, participants provided informed consent to include their data in the study). If a woman was unable to confirm maintenance of questionnaire-reported physical activity levels (e.g. she reported she stopped exercising shortly after onset of pregnancy), that woman’s data were not included. During personal telephone calls, average frequency (number of times per week) and duration (length of typical sessions) of physical activity information was confirmed in order to calculate total minutes per week during their pregnancy. Mode of exercise was also confirmed via telephone calls. Information directly regarding the intensity of exercise was not collected, albeit mode (e.g. jogging vs. walking) does offer some information about intensity, and we suspect intensity may be more difficult to recall from physical activity session months or years ago compared to frequency and duration. Because the federal physical activity guidelines suggest 150 minutes of moderate physical activity per week18,19, 150minutes/week of structured/planned physical activity was used as the criteria for selecting physical activity for the study, and all reported activities have corresponding metabolic equivalent values that would classify them as at least moderate intensity20.
Author Manuscript Author Manuscript
Delivery records were used to obtain mode of delivery, gestation age at delivery, type of labor (spontaneous, induced, or augmented), total time in labor, time in stage 2 of labor (pushing), and additional information regarding the labor and delivery process. Neonatal Apgar scores, birth weight, birth length, head circumference, cord blood gases, and nursery disposition were obtained from delivery records. Inductions included in the study were medically-indicated (i.e. hypertension, gestational diabetes, macrosomnia, intrauterine growth restriction, or post-dates). 2.2 Subjects Inclusions for the study included ages 18–44, pre-pregnancy BMI greater than or equal to 30kg/m2, viable pregnancy with no identified fetal abnormalities, and 37 weeks gestation or greater at admission to labor and delivery. Exclusions for the present study were multiple gestation pregnancy, diabetes mellitus prior to pregnancy, chronic hypertension prior to pregnancy, prior cesarean delivery or a scheduled cesarean delivery for the present pregnancy, and use of tobacco, illegal drugs, or alcohol during the pregnancy being studied.
Author Manuscript
For inclusion into the active group, patients had to report participating in physical activity for ≥150 min/week via clinic administered surveys at the initiation of prenatal care. Because these surveys were taken at the initiation of prenatal care, all women who met these criteria were called by the study team to confirm the maintenance of physical activity throughout pregnancy. If a woman reported a reduction in physical activity to
J Sports Med Phys Fitness. Author manuscript; available in PMC 2017 May 01. Published in final edited form as: J Sports Med Phys Fitness. 2017 May ; 57(5): 652–659. doi:10.23736/S0022-4707.17.06222-3.
Impact of physical activity during pregnancy on obstetric outcomes in obese women Rachel A. Tinius, PhD, ACSM-EP-C1, Alison G. Cahill, MD, MSCI2, and W. Todd Cade, PT, PhD1 1Program
in Physical Therapy, Washington University School of Medicine, St. Louis, Missouri
Author Manuscript
2Department
of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis,
Missouri
Abstract Aim—Maternal obesity is associated with complications and adverse outcomes during the labor and delivery process. In pregnant women with a healthy body weight, maternal physical activity during pregnancy is associated with better obstetric outcomes; however, the effect of maternal physical activity during pregnancy on obstetric outcomes in obese women is not known. The purpose of the study was to determine the influence of self-reported physical activity levels on obstetric outcomes in pregnant obese women.
Author Manuscript
Methods—A retrospective chart review was performed on 48 active obese women and 48 inactive obese women (N=96) who received prenatal care and delivered at the medical center during the past five years. Obstetric and neonatal outcomes were compared between the active and inactive groups. Results—Obese women who were active during pregnancy spent less total time in labor (13.4 hours vs. 19.2 hours, p=0.048) and were less likely to request an epidural (92% vs. 100%, p=0.04). When stratified by parity, active multiparous women spent significantly less total time in labor compared to inactive multiparous (6.2 hours vs. 16.7 hours, p=0.018). There were no statistical differences between groups in rates of cesarean deliveries or neonatal outcomes. Conclusion—Maternal physical activity during pregnancy appears to improve obstetric outcomes in obese women, and this improvement may be more pronounced among multiparous women. Our finding is of particular importance as pregnant obese women are at higher risk for adverse and delivery outcomes.
Author Manuscript
Keywords exercise; cesarean delivery; obesity; epidural
Corresponding author: Rachel A. Tinius, PhD, ACSM-EP-C, School of Kinesiology, Recreation, and Sport, Western Kentucky University, 1906 College Heights Blvd, #11089, Bowling Green, KY 42101, Phone: 270-745-5026, Fax: 314-286-1410, [email protected]. Conflicts of Interest: The authors have no conflicts of interest to disclose.
Tinius et al.
Page 2
Author Manuscript
1. Introduction The medical and economic burden of obesity is a major public health concern. The prevalence of maternal obesity has dramatically increased with one in three women entering pregnancy obese1. Maternal obesity has been associated with a wide array of adverse maternal and neonatal outcomes2 including elevated risk for complications during the labor and delivery process including slower progression of labor, labor dysfunction, and medically necessary cesarean deliveries3,4.
Author Manuscript
Labor complications in obesity include increased total duration of labor5 and slower progression of the early part of the first stage of labor3,6,7. Prolonged time in labor increases the risk for a number of unfavorable outcomes such as operative deliveries, infections, and adverse neonatal outcomes8–10. Maternal obesity has also been associated with active labor dysfunction including arrest of dilation and fetal distress11, both of which contribute to the elevated rate of cesarean deliveries among obese women3,4. In the United States, the rate of cesarean deliveries dramatically rose by 53% from 1996 to 2007, reaching 32% of all deliveries12. The public health impact of excess cesarean deliveries is substantial as cesarean deliveries are expensive and increase the risk for other morbidities such as severe bleeding, infections, painful scarring, blood clots, bowel obstructions, readmissions to the hospital, and longer-lasting pain4. With maternal obesity significantly elevating risk for cesarean deliveries, identification of methods to reduce the number of cesarean deliveries and improve the labor and delivery process for obese women is critical13.
Author Manuscript
In normal-weight women, regular physical activity during pregnancy has been shown to lower the incidence of cesarean deliveries14–17. Similarly, maternal physical activity during pregnancy in normal-weight women is associated with shorter active labors14,16. However, the influence of physical activity on the labor and delivery process and obstetric outcomes in women with pre-pregnancy obesity is not known. Therefore, the purpose of the study was to
examine obstetric outcomes in pregnant obese women who self-reported being physically active during pregnancy versus pregnant obese women who did not. We hypothesized that maternal physical activity during pregnancy would reduce occurrence rate of cesarean sections in pregnant obese women. We secondarily hypothesized that physically active obese women would spend less total time in labor, less time pushing, and would have neonates with higher Apgar scores, healthier birth weights, and less incidence of neonatal complications.
Author Manuscript
2. Materials and Methods 2.1 Study procedures A retrospective chart review was performed on women who received prenatal care at the Washington University School of Medicine’s Women’s Health Center between May 2009 and May 2014. All women treated at this clinic had private insurance, thus, it was considered a moderate-to-high income clinic. The patient’s age, weight, height, body mass index, race, parity, delivery history, gestational weight gain, and pregnancy complications
J Sports Med Phys Fitness. Author manuscript; available in PMC 2017 May 01.
Tinius et al.
Page 3
Author Manuscript
were obtained from their prenatal charts. Pre-pregnancy body mass index (BMI) was determined by weight and height at their first prenatal appointment- typically between eight and nine weeks gestation. If a patient presented for care later than nine weeks gestation, prepregnancy weight was based on self-report. Physical activity information was gathered from health history questionnaires distributed by the clinic at initiation of prenatal care. Selfreported physical activity information was confirmed via personal telephone calls (at which time, participants provided informed consent to include their data in the study). If a woman was unable to confirm maintenance of questionnaire-reported physical activity levels (e.g. she reported she stopped exercising shortly after onset of pregnancy), that woman’s data were not included. During personal telephone calls, average frequency (number of times per week) and duration (length of typical sessions) of physical activity information was confirmed in order to calculate total minutes per week during their pregnancy. Mode of exercise was also confirmed via telephone calls. Information directly regarding the intensity of exercise was not collected, albeit mode (e.g. jogging vs. walking) does offer some information about intensity, and we suspect intensity may be more difficult to recall from physical activity session months or years ago compared to frequency and duration. Because the federal physical activity guidelines suggest 150 minutes of moderate physical activity per week18,19, 150minutes/week of structured/planned physical activity was used as the criteria for selecting physical activity for the study, and all reported activities have corresponding metabolic equivalent values that would classify them as at least moderate intensity20.
Author Manuscript Author Manuscript
Delivery records were used to obtain mode of delivery, gestation age at delivery, type of labor (spontaneous, induced, or augmented), total time in labor, time in stage 2 of labor (pushing), and additional information regarding the labor and delivery process. Neonatal Apgar scores, birth weight, birth length, head circumference, cord blood gases, and nursery disposition were obtained from delivery records. Inductions included in the study were medically-indicated (i.e. hypertension, gestational diabetes, macrosomnia, intrauterine growth restriction, or post-dates). 2.2 Subjects Inclusions for the study included ages 18–44, pre-pregnancy BMI greater than or equal to 30kg/m2, viable pregnancy with no identified fetal abnormalities, and 37 weeks gestation or greater at admission to labor and delivery. Exclusions for the present study were multiple gestation pregnancy, diabetes mellitus prior to pregnancy, chronic hypertension prior to pregnancy, prior cesarean delivery or a scheduled cesarean delivery for the present pregnancy, and use of tobacco, illegal drugs, or alcohol during the pregnancy being studied.
Author Manuscript
For inclusion into the active group, patients had to report participating in physical activity for ≥150 min/week via clinic administered surveys at the initiation of prenatal care. Because these surveys were taken at the initiation of prenatal care, all women who met these criteria were called by the study team to confirm the maintenance of physical activity throughout pregnancy. If a woman reported a reduction in physical activity to
