Does infant sex moderate the effects of cannabis use in pregnancy on newborn outcomes?

Abstract

Objectives Cannabis use may be associated with adverse infant outcomes. Approximately 3% of pregnant women in British Columbia report cannabis use. Animal models show deleterious neurological effects for male offspring exposed to cannabis. Sex-specific adverse outcomes associated with human maternal tobacco use have also been observed. We sought to investigate whether infant sex modifies the associations between cannabis use in pregnancy and preterm birth (<32 and <37 weeks), size for gestational age at birth (>90th and <10th percentiles), and major congenital anomalies. Methods Population-based data from British Columbia's Perinatal Data Registry, containing information on 99% of all births in BC, were analysed from 2012–2017. Associations between cannabis use in pregnancy and infant outcomes were identified using adjusted binomial and multinomial logistic regression modeling with an interaction term added to identify if outcomes differed by infant sex. Models were adjusted for concomitant substance use, maternal characteristics and conditions, and infant sex. Results We found statistically significant associations between cannabis use in pregnancy and preterm birth (<32 weeks: adjOR 1.3, 95% CI 1.02–1.8; <37 weeks: adjOR 1.3, 95% CI 1.2–1.5) and small-for-gestational-age births (adjOR 1.3, 95% CI 1.2–1.4) but not for major congenital anomalies (adjOR 1.1, 95% CI 0.92–1.4) after adjusting for covariates. These findings were not dependent on infant sex. Conclusions While cannabis use in pregnancy is associated with preterm birth and small for gestational age, these effects were not found to vary by infant sex, suggesting that infants exposed to cannabis in utero are equally susceptible irrespective of sex at birth. Cannabis use may be associated with adverse infant outcomes. Approximately 3% of pregnant women in British Columbia report cannabis use. Animal models show deleterious neurological effects for male offspring exposed to cannabis. Sex-specific adverse outcomes associated with human maternal tobacco use have also been observed. We sought to investigate whether infant sex modifies the associations between cannabis use in pregnancy and preterm birth (<32 and <37 weeks), size for gestational age at birth (>90th and <10th percentiles), and major congenital anomalies. Population-based data from British Columbia's Perinatal Data Registry, containing information on 99% of all births in BC, were analysed from 2012–2017. Associations between cannabis use in pregnancy and infant outcomes were identified using adjusted binomial and multinomial logistic regression modeling with an interaction term added to identify if outcomes differed by infant sex. Models were adjusted for concomitant substance use, maternal characteristics and conditions, and infant sex. We found statistically significant associations between cannabis use in pregnancy and preterm birth (<32 weeks: adjOR 1.3, 95% CI 1.02–1.8; <37 weeks: adjOR 1.3, 95% CI 1.2–1.5) and small-for-gestational-age births (adjOR 1.3, 95% CI 1.2–1.4) but not for major congenital anomalies (adjOR 1.1, 95% CI 0.92–1.4) after adjusting for covariates. These findings were not dependent on infant sex. While cannabis use in pregnancy is associated with preterm birth and small for gestational age, these effects were not found to vary by infant sex, suggesting that infants exposed to cannabis in utero are equally susceptible irrespective of sex at birth.