Miscarriage is an inability to complete the normal process of pregnancy and childbirth and represents a major concern for pregnant women that can be an emotionally devastating event. While it has been suggested that engaging in strenuous physical activity might be associated with an elevated risk of miscarriage, there is a recent systematic review that suggested that prenatal exercise is not associated with fetal mortality. The aim of this systematic review and meta-analysis (SR + MA) was to assess the effects of physical activity during pregnancy on the likelihood of experiencing a miscarriage (Registration No.: CRD42022370629). Thirteen randomized clinical trials (3728 pregnant women) were included. Meta-analyses were conducted with the dependent variable being the miscarriage ratio in each study. The total risk ratio (RR) sum was calculated using a random effects model. The I2 statistic was utilized to quantify the heterogeneity observed in the results. No significant association between exercise during pregnancy and the occurrence of miscarriage was found (RR = 0.83 95% CI = 0.83 (0.49-1.41); z = 0.69, p = 0.49; I2 = 0.00%, Heterogeneity p = 0.91). Results of the present SR + MA showed no increase in miscarriage risk in those who engaged in low- to moderate-intensity exercise compared to those who did not.
Keywords: exercise; miscarriage; physical activity; pregnancy.