A systematic review of behavioral interventions to improve maternal outcomes for women in the United States at high risk for adverse pregnancy outcomes.

Introduction: Adverse pregnancy outcomes (APOs), including hypertensive disorders, gestational diabetes, and preterm birth, affect 10-20% of U.S. pregnancies and substantially increase long-term cardiovascular disease (CVD) risk. While behavioral interventions during pregnancy may reduce risk factors for APOs, evidence remains limited on which strategies are effective for high-risk women. This systematic review addresses this gap by examining patterns in intervention design, outcome reporting, and areas where research fails to meet the needs of at-risk pregnant populations. Methods: We searched PubMed and the Cochrane Central Register of Controlled Trials for articles published from January 1, 2005, to June 30, 2024. Following PRISMA guidelines, we included U.S.-based randomized controlled trials of behavioral interventions: diet, physical activity, sleep, mindfulness, or self-monitoring, delivered during pregnancy to women at high risk of APOs. See Supplemental Figure S4 for the PRISMA Checklist. Two reviewers independently performed screening, data extraction, and risk-of-bias assessment using the Cochrane Risk of Bias Tool. Results: Of 3,261 studies screened, 43 met inclusion criteria. Most interventions focused on individuals with prepregnancy overweight or obesity, often excluding those with other CVD risk factors. Thirty-six trials reported improvements in outcomes such as gestational weight gain (GWG), postpartum weight retention, blood pressure, or biomarkers. Interventions combining diet and physical activity showed the greatest benefit. However, only four trials demonstrated improvements in clinical outcomes like gestational diabetes, hypertensive disorders, or lipid profiles. Outcome measures and timelines varied widely, and few trials included postpartum follow-up or assessed outcomes beyond GWG. Discussion: Although behavioral interventions during pregnancy are growing in number, trials are limited by heterogeneous designs, narrow inclusion criteria, and inconsistent outcome reporting. The focus on GWG and exclusion of women with complex risk profiles reduce generalizability. Inclusive research with standardized outcomes is urgently needed to improve maternal health and reduce long-term CVD risk.