Association Between Prenatal Multiple Micronutrient Supplementation and Pregnancy Outcomes; a Prospective Longitudinal Study in Parepare, Indonesia

Objectives: The study aims to investigate the effect of prenatal multiple micronutrient supplementation (MMS) on pregnancy outcomes in real-world setting, with variations in timing of MMS introduction and total number of MMS tablets consumed. Methods: During implementation of the MMS program in Parepare, Indonesia, we performed prospective longitudinal data collection. Of the 1216 pregnant women initially enrolled, 953 mother-child dyads had complete newborn data. Data on start of MMS (trimester), total MMS consumption, gestational age, birth weight, birth length, and delivery mode were collected. Associations between total MMS consumption and birth outcomes were assessed by binary logistic and cubic spline regression. Results: Among all newborns, 4.2% were born preterm, 16.0% were small for gestational age, and 5.7% had low birth weight (< 2500 gram). On average, women consumed 94.3 ± 43.0 MMS tablets (range 15-210 tablets). Approximately 54.5% started during first trimester (117.5 ± 39.0); 40.6% during second trimester (70.3 ± 28.1), while only 4.9% began during third trimester (36.4 ± 15.1). Analysis showed that for each additional tablet of MMS consumed, odds of preterm birth (OR =0.991 95% CI: 0.984, 0.999) and low birth weight (OR =0.992, 95% CI: 0.985, 0.999) decreased by 1%. No association was found with SGA birth (OR=0.998 95% CI: 0.994, 1.002). After adjustment for MMS start and anaemia status, results remained unchanged. Cubic splines revealed a linear association for LBW and a possible cut-off for preterm birth around 100 tablets. Conclusions: These results suggest that higher MMS adherence may reduce risk of preterm birth and low birth weight. With adherence to a minimal intake of 90 tablets, a risk reduction of approximately 50% could be achieved. Therefore, encouraging women to consume MMS according to the recommendations is necessary to obtain optimal benefits. These findings support the ongoing implementation of MMS and the need to focus on early introduction and adherence to MMS intake throughout pregnancy. Funding Sources: Indonesia Endowment Funds for Education (LPDP).