Evaluating the Impact of CenteringPregnancy Program Versus Individual Prenatal Care on Gestational Weight Gain

Introduction: The CenteringPregnancy (CP) program-proven to reduce preterm births-was modified to achieve more optimal gestational weight gain (GWG) by an intentional incorporation of nutrition education. We compared the effect of the modified CP program versus individual prenatal care (IPNC) on GWG. Methods: This observational study used linked birth certificate data and hospital discharge records of women who received prenatal care (PNC) in South Carolina Midlands' obstetric clinics between 2015 and 2019. Linear and multinomial logistic regressions were used to compare participants in CP (n = 568) versus IPNC on weight gain, measured by total GWG (delivery weight minus prepregnancy weight), weekly rate of weight gain, and meeting the Institute of Medicine's recommendations (inadequate, adequate, and excessive GWG). Nonrandom assignment to program was controlled by propensity scoring. Results: CP participants differed from IPNC participants in race, nulliparous, education, and type of health insurance, but not in parity or month PNC began (p-Value <0.05). CP and IPNC participants had a similar GWG experience: total GWG (coef(β) = -0.054; 95% confidence interval [CI] -0.78 to 0.6), total weekly weight gain (coef(β) = -0.004; 95% CI -0.03 to 0.03), total GWG category (inadequate GWG: RRR = 0.85, 95% CI 0.64-1.21, and excessive GWG: relative risk ratio (RRR) = 0.92, 95% CI 0.71-1.20 vs. adequate), and weekly weight gain category (inadequate GWG: RRR = 0.73, 95% CI 0.53-1.01, and excessive GWG: RRR = 0.83, 95% CI 0.61-1.13 vs. adequate). Conclusion: The CP program with an enhanced nutritional knowledge component was not associated with achieving recommended GWG. Further investigation is needed to explain the lack of impact.