Prenatal Exercise and Pre-gestational Diseases: A Systematic Review and Meta-analysis

Objective: This study sought to examine the effect of prenatal exercise on birth outcomes in women with pre-gestational diseases, including chronic hypertension, type 1 diabetes, and type 2 diabetes.

Methods: A structured search of online databases up to June 8, 2018 was conducted. Studies of all designs and languages were included if they contained information on the population (pregnant women with pre-gestational diseases), intervention (subjective or objective measures of frequency, intensity, duration, volume, or type of exercise), comparator (no exercise or different frequency, intensity, duration, volume, or type of exercise), and outcome (birth weight, macrosomia [birth weight >4000 g], large for gestational age, low birth weight [<2500 g], small for gestational age [<10th percentile], Apgar score, preterm birth [<37 weeks], Caesarean section (CS), preeclampsia, and glycemic control).

Results: A total of five studies (n = 221 women) were included. Canadian Task Classification was designated as level I. "Low" to "very low" quality evidence revealed that prenatal exercise reduced the odds of CS by 55% in women with type 1 diabetes and chronic hypertension (OR 0.45; 95% CI 0.22-0.95, I² = 0%). The odds of low (<2500 g) or high (>4000 g) birth weight, Apgar score at 1 and 5 minutes, preeclampsia, and preterm birth were not different between women who exercised and those who did not.

Conclusion: Prenatal exercise reduced the odds of CS and did not increase the risk of adverse maternal or neonatal outcomes in mothers with pre-gestational medical conditions. Findings are based on limited evidence, thus suggesting a need for high-quality investigations on exercise in this population of women.