Impact of Prenatal Nutrition Interventions on Infant Longitudinal Growth: A Secondary Analysis of the Mumta Pregnant Women Trial in Pakistan

Objective To evaluate the effect of antenatal interventions on infant growth from birth till 12 months of age. Patients and Methods In the Mumta Pregnant Women (PW) trial conducted from July 22, 2019, to February 1, 2022, PW were randomly assigned (1:1:1:1) to one of 4 groups: control (standard antenatal care), balanced energy protein supplementation (BEP alone), BEP/azithromycin (AZ), or BEP/nicotinamide/choline. Infant growth trajectories were modeled using the broken stick method and k-means clustering for weight-for-age (WAZ), length-for-age (LAZ), and weight-for-length z-scores. Random effect models assessed the impact of interventions and covariates (maternal age, height, parity, and mode of delivery) on growth outcomes. Results From 1884 PW randomized, 1678 infants were born alive and included in this analysis (control n=410, BEP only n=418, BEP/AZ n=428, and BEP/choline/nicotinamide n=422). The mean growth trajectories revealed that the BEP/AZ arm had higher mean WAZ, LAZ, and weight-for-length scores compared with control. BEP/AZ arm had the highest proportion of infants in the thriving cluster across WAZ (control 34.4 % and BEP/AZ 35.5 %), and LAZ (control 31.7%, BEP/AZ 33.4%) measures. The odds of membership to the faltering cluster were reduced in the BEP/AZ arm based on WAZ (control 22.3%, BEP/AZ 15.7%), and LAZ measures (control 22.1%, BEP/AZ 17.7%) as compared with control. Across all measures, faltering was 4-fold higher in small-for-gestational-age infants and 2-fold higher among infants born to undernourished mothers. Conclusion Antenatal interventions, such as BEP and prophylactic AZ, may have the potential to support and sustain infant growth outcomes in low-resource settings. Trial Registration Clinicaltrials.gov Identifier: NCT04012177.