Risk factors for neonatal mortality: an observational cohort study in Sarlahi district of rural southern Nepal

Abstract

Objectives: To assess the association between maternal characteristics, adverse birth outcomes (small-for-gestational-age (SGA) and/or preterm) and neonatal mortality in rural Nepal.

Design: This is a secondary observational analysis to identify risk factors for neonatal mortality, using data from a randomised trial to assess the impact of newborn massage with different oils on neonatal mortality in Sarlahi district, Nepal.

Setting: Rural Sarlahi district, Nepal.

Participants: 40 119 pregnant women enrolled from 9 September 2010 to 16 January 2017.

Main outcome: The outcome variable is neonatal death. Cox regression was used to estimate adjusted Hazard Ratios (aHRs) to assess the association between adverse birth outcomes and neonatal mortality.

Results: There were 32 004 live births and 998 neonatal deaths. SGA and/or preterm birth was strongly associated with increased neonatal mortality: SGA and preterm (aHR: 7.09, 95% CI: (4.44 to 11.31)), SGA and term/post-term (aHR: 2.12, 95% CI: (1.58 to 2.86)), appropriate-for-gestational-age/large-for-gestational-age and preterm (aHR: 3.23, 95% CI: (2.30 to 4.54)). Neonatal mortality was increased with a history of prior child deaths (aHR: 1.53, 95% CI: (1.24 to 1.87)), being a twin or triplet (aHR: 5.64, 95% CI: (4.25 to 7.48)), births at health posts/clinics or in hospital (aHR: 1.34, 95% CI: (1.13 to 1.58)) and on the way to facilities or outdoors (aHR: 2.26, 95% CI: (1.57 to 3.26)). Risk was lower with increasing maternal height from <145 cm to 145-150 cm (aHR: 0.78, 95% CI: (0.65 to 0.94)) to ≥150 cm (aHR: 0.57, 95% CI: (0.47 to 0.68)), four or more antenatal care (ANC) visits (aHR: 0.67, 95% CI: (0.53 to 0.86)) and education >5 years (aHR: 0.75, 95% CI: (0.62 to 0.92)).

Conclusion: SGA and/or preterm birth are strongly associated with increased neonatal mortality. To reduce neonatal mortality, interventions that prevent SGA and preterm births by promoting ANC and facility delivery, and care of high-risk infants after birth should be tested.

Trial registration number: NCT01177111.

Keywords: Epidemiology; Factor Analysis, Statistical; NEONATOLOGY; Primary Prevention; Public health; Risk Factors.

Figure 1

Flow diagram for participants in Nepal Oil Massage Study. *Data collection was halted for 6 weeks in December 2016. LB, Livebirth; SB, Stillbirth; GA, Gestational Age; LFUP, Lost to Follow Up.

Figure 2

Cumulative neonatal mortality curves by SGA/preterm excluding imputed data. AGA, appropriate-for-gestational-age; LGA, large-for-gestational-age; SGA, small-for-gestational-age.