Physical Activity Interventions During Pregnancy: A Registry-Based Analysis of Completed Phase 4 Trials and Gaps in Maternal Functioning and Related Outcomes

Abstract

Physical activity during pregnancy is associated with numerous benefits for maternal and fetal health, yet its integration into routine prenatal care remains inconsistent. Understanding the current research landscape is essential to identify gaps and guide future interventions. This cross-sectional study aimed to characterize completed Phase 4 clinical trials registered on ClinicalTrials.gov that investigated physical activity as a primary intervention in pregnancy. Methods: A registry-based cross-sectional analysis was conducted using ClinicalTrials.gov. On March 20, 2025, a structured search was performed using the terms “pregnancy” and “exercise,” with filters applied to identify completed, interventional, Phase 4 trials. Trials were included if they involved physical activity interventions in pregnant populations. Extracted data included study design, sample size, intervention characteristics, and primary outcomes, which were summarized descriptively. Results: Of the 531,504 records screened, 1,667 trials involved both pregnancy and exercise. After applying the eligibility criteria, five completed Phase 4 trials were identified. Three trials focused on women with polycystic ovary syndrome, examining outcomes such as ovulation rates, pregnancy rates, insulin sensitivity, and cardiovascular health. The remaining two trials investigated gestational weight gain and maternal-fetal outcomes, including gestational diabetes, anemia, and birth weight. Interventions ranged from structured exercise programs to combined behavioral and pharmacologic strategies. Conclusion: The number of completed Phase 4 trials evaluating prenatal physical activity is limited and primarily concentrated on reproductive and metabolic outcomes in women with polycystic ovary syndrome. Research addressing broader maternal and neonatal outcomes, such as mental health, postpartum recovery, and infant development, remains sparse. Expanding clinical research in this area is essential to inform evidence-based prenatal care practices.