Effect of the Enhancing Nutrition and Antenatal Infection Treatment (ENAT) intervention on birth weight in Ethiopia: A cluster randomized controlled trial

Abstract

Background The Enhancing Nutrition and Antenatal Infection Treatment (ENAT) intervention was implemented in Ethiopia to improve newborn birth weight by strengthening the contents and quality of antenatal care (ANC), especially point-of-care testing for maternal infections. This study examined the effect of the ENAT intervention on birth weight. Methods We conducted a cluster randomized controlled trial of 22 clusters (health centers), randomized equally between 11 intervention and 11 control clusters. This study enrolled and followed pregnant women from ANC booking to the end of pregnancy or loss to follow-up. The primary outcome of this study was mean birth weight, and the incidence of low birth weight (LBW) was the secondary outcome. We presented univariate comparisons of outcomes between the intervention and control arms using cluster-adjusted t tests for mean birth weight and cluster-weighted chi-square tests for LBW. Multilevel analyses using random effects models were performed to adjust for clustering and individual-level covariates. Results We enrolled and followed up 4,868 and 4,821 pregnant women in the intervention and control arms, respectively, from March 2021-July 2022. During follow-up, 3445 and 3192 pregnant women delivered in the health centers, and birth weight measurements of their babies were recorded within 48 hours. The mean birth weight was 3,152 grams (standard deviation (SD) = 339.8 grams) in the intervention and 3,044 grams (SD = 353.8 grams) in the control arms (mean difference, 108 grams; 95% confidence interval (CI): 91.3-124.6; P = 0.000). Adjusting for clustering and several covariates, the mean birth weight remained significantly higher in the intervention arm than in the control arm (adjusted ß coef., 114.3; p = 0.011). The incidence of LBW was 4.7% and 7.3% in the intervention and control arms, respectively. The adjusted risk of LBW was significantly lower by 36% in the intervention arm than in the control arm (adjusted relative risk, 0.645; p = 0.027). Conclusion This study provided sufficient evidence of the effectiveness of the ENAT intervention in improving birth weight in the study population. The intervention demonstrated that an increase in birth weight can be attained by availing point-of-care testing and strengthening infection prevention within the ANC platform of public health facilities in a low-income setting. Trial Registration: The study was retrospectively registered at Pan African Clinical Trial Registry (PACTR) database dated 09/05/2023. The unique identification number for the registry is PACTR202305694761480. The PACTR is the WHO recognized clinical trials registry in Africa. It can be accessed at https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=25493.