Does Maternal Carbon Monoxide Exposure Determine Birth Outcomes? A Hospital Based Study in South-South Nigeria

Abstract

Background: Neonatal outcomes, such as birth weight and Apgar scores, are key indicators of intrauterine health and immediate postnatal adaptation. Several maternal and obstetric factors influence these outcomes; however, the role of environmental exposures, such as carbon monoxide (CO), remains insufficiently characterised. Aim: This study aimed to explore the association between maternal carbon monoxide exposure and neonatal outcomes. Methodology: This cross-sectional analytical study was conducted among 240 pregnant women at Rivers State University Teaching Hospital, Port Harcourt, between 2024 and 2025. Using consecutive sampling, maternal carbon monoxide exposure was measured with a Smokerlyzer® device, and neonatal outcomes, including birth weight and Apgar scores at 1 and 5 minutes, were recorded at delivery. Data were analysed using descriptive and inferential statistical methods, with significance set at p < 0.05. Results: The mean maternal CO level was low across the study population. Maternal CO was not significantly correlated with birth weight (p = 0.140) or Apgar scores (p > 0.05), and it was not significantly associated with birth weight in the regression analysis (p = 0.097). Conclusion: Maternal carbon monoxide exposure at the levels observed was not associated with adverse neonatal outcomes. This study was unable to detect effects within the narrow exposure range.