Implementation effectiveness of an antenatal lifestyle intervention to optimize gestational weight gain in women with...

The objective of this study was to evaluate a lifestyle intervention implemented into routine antenatal care to optimize gestational weight gain (GWG) and outcomes using the Reach, Efficacy, Adoption, Implementation, and Maintenance (RE-AIM) framework.

This study was an embedded pragmatic behavioral intervention delivered by a health coach and supported by a physician over five sessions for women with a prepregnancy BMI between 25 and 43 kg/m² who were <23 weeks' gestation in an Australian maternity service. Both intervention and standard care received routine antenatal care. The primary outcome was effectiveness in reducing excess GWG, and the secondary outcomes were reach, adoption, implementation, and maintenance and maternal and neonatal outcomes using the RE-AIM framework.

For the "Reach" aspect, 90% of eligible women were included (N = 404; n = 202 intervention and n = 202 standard care). For the "Efficacy" aspect, there were no differences in proportion exceeding GWG recommendations or mean GWG between groups. Secondary analysis excluding women with gestational diabetes showed that a lower proportion of women in the intervention group had GWG above recommendations (β coefficient 0.51, 95% CI: 0.27 to 0.97; p = 0.04), with less GWG (β coefficient -1.93 kg, 95% CI: -3.63 to -0.24; p = 0.03). For the "Adoption" aspect, qualitative analysis of staff/participants demonstrated strong support for service. For the "Implementation" aspect, strong fidelity (implementation according to study plan) and staff/participant acceptability were observed. Finally, for the "Maintenance" aspect, the program has continued for 4 years with plans/funding for scale-up.

Lifestyle intervention did not alter the overall proportion with excess GWG or total GWG. Secondary analysis, excluding women with gestational diabetes mellitus, showed less GWG. This demonstrates implementation and maintenance of the intervention in routine antenatal care, generating new knowledge within the RE-AIM framework.