Evaluating the relationship of in utero nicotine exposure with hypoglycemia after delivery: An observational study

Abstract

Background: Hypoglycemia in neonates is common and contributes to 4.0-5.8% of neonatal intensive care unit (NICU) admissions. In utero nicotine exposure is underexplored as a potential contributor to neonatal hypoglycemia. Rat models have shown that in utero nicotine exposure can be associated with a reduction in pancreatic beta cell mass, leading to glucose dysregulation. The primary aim of this work is to study the risk of developing hypoglycemia after birth in a population of in utero nicotine-exposed neonates.

Methods: We conducted a retrospective matched cohort study that augmented an existing dataset of neonates admitted to a level IV NICU with household-based in utero nicotine exposure (N = 335). Neonates in the control group parents denied household smoking (N = 325), were born within a 6-month timeframe, and were within a birthweight of 50 grams of a nicotine-exposed neonate. Data reviewed included gestational age, growth parameters, maternal history of diabetes, and glucose levels within the first three hours of life per unit protocol.

Results: 660 neonates were included in the analysis. In utero nicotine exposure demonstrated a 94.3% posterior probability (PP) for greater hypoglycemia risk (RR = 1.185, 95% CrI = [0.953, 1.445]). A 94.6% PP was demonstrated when neonates who were small for gestational age, intrauterine growth-restricted, and born to diabetic mothers were excluded (n = 482; RR = 1.271, 95% CrI = [0.946, 1.669]).

Conclusion: Nicotine exposure in utero was found to be a potential risk factor for developing hypoglycemia after birth. Mechanisms of action should be explored, and additional research on in utero nicotine exposure risks should follow.

Keywords: Late preterm neonate; maternal substance use; neonatal hypoglycemia; neonatology; nicotine exposure.

Fig. 1.

Neonate Screening and Enrolment Disposition by Household-based Nicotine Exposure and Risks Factors for Hypoglycemia.

Fig. 2.

Hypoglycemia by Household Smoking Status in Full Sample & Subsample*. *Subsample analysis excluded three independent hypoglycemia risk factors (Intrauterine growth restriction, small for gestational age, and neonates born to diabetic mothers).