Risk factors and neonatal/infant mortality risk of small-for-gestational-age and preterm birth in rural Nepal

Abstract

Objective: Our study seeks to elucidate risk factors for and mortality consequences of small-for-gestational-age (SGA) and preterm birth in rural Nepal. In contrast with previous literature, we distinguish the epidemiology of SGA and preterm birth from each other.

Methods: We analyzed data from a maternal micronutrient supplementation trial in rural Nepal (n = 4130). We estimated adjusted risk ratios (aRR) for risk factors of SGA and preterm birth, and aRRs for the associations between SGA/preterm birth and neonatal/infant mortality. We used mutually exclusive categories of term-appropriate-for-gestational-age (AGA), term-SGA, preterm-AGA, and preterm-SGA (with term-AGA as reference) in our analyses.

Results: Stunted (<145 cm) and wasted (<18.5 kg/m²) women both had increased risk of having term-SGA (aRR 1.36, 95% CI: 1.14-1.61, aRR 1.22, 95% CI: 1.09–1.36 respectively) and preterm-SGA (aRR 2.48, 95% CI: 1.29–4.74, aRR 1.99, 95% CI: 1.33–2.97 respectively), but not preterm-AGA births. Similar results were found for low maternal weight gain per gestational week. Those born preterm-SGA generally experienced the highest neonatal and infant mortality risk, although term-SGA and preterm-AGA newborns also had statistically significantly high mortality risks compared to term-AGA babies.

Conclusions: SGA and preterm birth have distinct risk factors and mortality patterns. Maternal chronic and acute malnutrition appear to be associated with SGA outcomes. Because of high SGA prevalence in South Asia and the increased neonatal and infant mortality risk associated with SGA, there is an urgent need to intervene with effective interventions.

• Maternal
• neonatal mortality
• preterm
• SGA

Acknowledgements

This study was carried out by the Nepal Nutrition Intervention Project-Sarlahi and the Center for Human Nutrition, Department of International Health of the Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA, in collaboration with the National Society for the Prevention of Blindness, Kathmandu, Nepal. Support was provided through Grant #614 (Global Control of Micronutrient Deficiency) from Bill and Melinda Gates Foundation, Seattle, WA, USA. The original antenatal micronutrient supplementation trial was conducted under the Micronutrients for Health Cooperative Agreement (CA) No. HRN-A-00-97-00015-00 and the Global Research Activity No. GHS-A-00-03-00019-00 between the Johns Hopkins University and the Office of Health, Infectious Diseases and Nutrition, United States Agency for International Development, Washington, DC, USA, with additional support from the Sight and Life Global Nutrition Research Institute, Baltimore, MD, USA. Funding for the analysis was provided by the Bill and Melinda Gates Foundation [810-2054] by a grant to the US Fund for UNICEF to support the activities of the Child Health Epidemiology Reference Group.

Declaration of interest

The authors report no declarations of interest.

Supplementary material avaiable online

Supplementary Tables S1, S2a and S2b, S3