In utero cannabis exposure tied to adverse neonatal health outcomes

Maternal cannabis use during pregnancy appears to contribute to increased risk of adverse neonatal health outcomes, including low birth weight (LBW) and small for gestational age (SGA), as reported in a study.

The study included 364,924 parent-infant dyads, where the pregnant parent was screened for cannabis use as part of standard prenatal care. In utero cannabis exposure was defined as self-reported use of the substance at the outset of pregnancy and/or a positive urine toxicology test for cannabis at any time during pregnancy and self-reported frequency of use (daily, weekly, at least monthly, never, unknown; secondary).

Generalized estimating equation models adjusted for potential confounding factors were used to examine the association of in utero cannabis exposure with neonatal outcomes (ie, LBW, SGA, preterm birth, neonatal intensive care unit [NICU] admission, and infant respiratory support).

A total of 22,624 infants (6.2 percent) were exposed to cannabis in utero. In utero cannabis exposure was associated with greater likelihood of LBW (adjusted odds ratio [aOR], 1.20, 95 percent CI, 1.12–1.28), SGA (aOR, 1.24, 95 percent CI, 1.18–1.30), preterm birth (<37 weeks; aOR, 1.06, 95 percent CI, 1.00–1.13), and NICU admission (aOR, 1.06, 95 percent CI, 1.01–1.11).

A suggestive association was found for early preterm birth (<34 weeks; aOR, 1.11, 95 percent CI, 1.00–1.23; p=0.055) but not with respiratory support (aOR, 1.07, 95 percent CI, 0.97–1.18).

Dose-response analysis showed that the odds of LBW and SGA increased with increasing frequency of prenatal cannabis use by the pregnant parent.

Sensitivity analyses further supported the association for LBW and SGA only.

The findings highlight the need for clinicians to counsel individuals who are pregnant or considering pregnancy about the potential adverse neonatal health outcomes associated with prenatal cannabis use.