Getting active during pregnancy leads to improved obstetric outcomes

Pregnant women may do well to exercise at an adequate amount, as it lowers the likelihood of adverse obstetric outcomes independent of blood pressure (BP), according to a study presented at the Society for Maternal-Fetal Medicine (SMFM) 40th Annual Pregnancy Meeting.

The investigators performed a secondary analysis of nuMom2b* to investigate interactions between physical activity (PA), diet, blood pressure (BP) and other covariates. They looked at 3,627 nulliparous women, none of whom had stage 2 hypertension, taking antihypertensives and delivered at <22 weeks.

Based on the ACC/AHA classification, BP was normal in 2,943 women (81 percent), variable in 561 (15 percent) and elevated in 123 (3.4 percent). Women with high BP levels were more likely to have higher body mass index, pregestational diabetes, caesarean delivery and be prescribed activity restriction (AR).

The incidence of the primary composite outcome—defined as hypertensive disorders of pregnancy (HDP), small-for-gestational age, preterm birth, placental abruption and stillbirth—differed by BP status (p<0.001), occurring with greatest frequency in the group of women with elevated BP (33 percent), followed by the groups with transient BP (26 percent) and normal BP (17 percent). [SMFM 2020, abstract 1102]

A similar pattern of incidence was noted for HDP: 25 percent in the elevated BP group, 18 percent in the transient BP group and 8.5 percent in the normal BP group (p<0.001).

Multivariable logistic regression revealed an inverse association between the composite of adverse obstetric outcomes and adequate PA (defined as >150 minutes of moderate or >75 minutes of vigorous activity weekly at 22–30 weeks gestation). There was no significant interaction noted between BP group and PA.

Risk factors for adverse obstetric outcomes included variable BP, age >40 years, diabetes, AR and obesity. Diet was not included in the model, because only a single woman was compliant with a diet defined as meeting Alternative Healthy Eating Index criteria for moderation of sodium, refined grains and empty calories.

The results were consistent in an analysis excluding women with AR.

According to guidelines, women should engage in ≥150 minutes (for example, 30 minutes a day, five days a week) of moderate-intensity aerobic physical activity per week, such as brisk walking, during and after their pregnancy.  [https://www.cdc.gov/physicalactivity/basics/pregnancy/index.htm]

Doing regular exercise during pregnancy has several benefits, such as improving or maintaining physical fitness, managing weight, reducing the risk of gestational diabetes in obese women, and enhancing psychological well-being. [https://www.acog.org/Clinical-Guidance-and-Publications/Committee-Opinions/Committee-on-Obstetric-Practice/Physical-Activity-and-Exercise-During-Pregnancy-and-the-Postpartum-Period]