(747) Next Steps for Group Prenatal Care Research: Shifting from Intervention Design to Implementation Science

Despite evidence that group prenatal care (GPC) attendance ≥5 visits improves perinatal outcomes, recent negative trial results may reflect implementation challenges rather than intervention failure. This study analyzed the GPC engagement cascade to identify critical transition points where targeted implementation strategies may optimize intervention delivery.

Study Design:

We conducted a cross-sectional analysis of a multi-site randomized controlled trial from 2021-2025. The study was conducted at 6 sites: 2 academic institutions and 4 community health centers. Associations between GPC receipt (1^st visit attendance) and retention (≥ 5 visit attendance) rates were assessed using Pearson’s correlation coefficients. Sequential dropout rates were calculated as the proportion lost at each stage relative to the prior stage.

Results:

Of 526 eligible patients, 307 (58.4%) were recruited into the study and 205 were randomized to GPC.  Sequential dropout analysis showed: 41.6% (219/526) lost at recruitment, 26.8% (55/205) lost after randomization, and 34.0% (51/150) lost after initial attendance. First-visit attendance was revealed as the critical bifurcation point: Probability[P](optimal engagement|receipt) = 66.0% overall versus P(optimal engagement|no receipt) = 0%. Site-level correlation between receipt and retention was strong (r=0.88, p< 0.05), with receipt explaining 77% of variance in retention.

Conclusion:

Less than half of patients randomized to GPC achieve the 5-session threshold associated with improved pregnancy outcomes. The strong correlation between receipt and retention across sites, combined with conversion rates among first-time attendees, suggests that implementation quality—rather than intervention design—may determine trial outcomes.  Future research should prioritize testing strategies to optimize initial patient engagement, as dismissing GPC based on implementation failures would abandon a potentially effective intervention before distinguishing implementation challenges from intervention ineffectiveness.