Resistance training in pregnancy: systematic review and meta-analysis of pregnancy, delivery, fetal and pelvic floor outcomes and call to action.

Objective: Resistance training (RT) has wide-ranging health benefits that may extend to pregnancy. This systematic review aimed to evaluate the influence of RT as a sole intervention or as part of a multicomponent exercise programme on pregnancy, delivery, fetal and pelvic floor outcomes.

Design: A systematic review and meta-analysis were performed. Risk of bias was performed using the Johanna Briggs Institute risk of bias tool.

Data sources: Six databases were searched from inception to 15 March 2024.

Eligibility criteria: Studies were eligible for inclusion if pregnant individuals performed a RT intervention of any intensity, compared with usual care or a non-RT intervention. Outcomes included pregnancy outcomes (rates of gestational hypertension, pre-eclampsia, gestational diabetes and perinatal mood disorders), delivery outcomes (rates of caesarean section, perineal tearing, instrumented delivery and length of labour), fetal outcomes (birth mass, microsomia, macrosomia and gestational age) and rates of pelvic floor disorders.

Results: Overall, 50 studies (47 619 participants) from 14 countries were included in this review. There were 45 randomised controlled trials, 3 non-randomised interventions and 2 observational studies. Sixteen studies were considered low risk of bias, 27 studies were of moderate risk of bias and seven were classified as high risk of bias. Ninety per cent of studies were multicomponent programmes, and the dosage of RT interventions was generally low-to-moderate. Reporting of RT prescription, progression and use of appropriate loading guidance was poor. RT was associated with a reduction in the odds of gestational hypertension (OR 0.42, 95% CI 0.27 to 0.66; I²=0%), gestational diabetes (OR 0.62, 95% CI 0.48 to 0.79; I²=0%), perinatal mood disorders (OR 0.48, 95% CI 0.32 to 0.73; I²=0%) and macrosomia (OR 0.67, 95% CI 0.50 to 0.88; I²=23%) compared with control groups.

Conclusions: RT, alone or as part of a multicomponent intervention, has significant health benefits during pregnancy. As the majority of interventions are multicomponent, and the aerobic programmes are more appropriately dosed, understanding the impact of RT on the pregnant person is challenging, and studies using currently accepted RT guidelines for exercise dosage and progression are needed.