Concurrent prenatal cannabis, nicotine use tied to adverse maternal, neonatal outcomes

Key takeaways:

• Infant and neonatal death, small for gestational age and preterm birth increased with concurrent cannabis and nicotine use vs. nonuse.
• Severe maternal morbidity was highest for concurrent substance users.

Concurrent use of cannabis and nicotine during pregnancy vs. use of either substance alone was tied to increased risks for infant and neonatal death and maternal and neonatal morbidity, researchers reported.

“Numerous studies have demonstrated the detrimental effects of prenatal tobacco exposure, primarily nicotine exposure, on perinatal outcomes, including prematurity, low birth weight and stillbirth. Currently, there is a paucity of epidemiological data regarding the effects of combined prenatal exposure to both cannabis and nicotine products,” B. Adam Crosland, MD, MPH, department of obstetrics and gynecology in the division of maternal fetal medicine at Oregon Health & Science University, and colleagues wrote in JAMA Network Open. “Emerging evidence indicates that cannabis use exacerbates the negative impacts of nicotine product exposure, and dual abstinence may result in better outcomes following cessation.”

Crosland and colleagues conducted a retrospective population-based cohort study using linked hospital discharge data from the California Department of Health Care Access and Information and vital statistics data from the California Department of Public Health to identify 3,129,259 pregnant women (mean age, 29.3 years) from 2012 to 2019. All women had singleton pregnancies at gestational ages 23 to 42 weeks.

Primary outcomes were infant and neonatal death, small for gestational age infants and preterm birth.

Overall, 0.7% of women used cannabis, 1.8% used nicotine and 0.3% used both cannabis and nicotine in pregnancy.

Findings demonstrated that women who used cannabis or nicotine alone in pregnancy, compared with nonusers, had increased rates of infant (0.7% and 0.7% vs. 0.3%) and neonatal (0.3% and 0.3% vs. 0.2%) death, small for gestational age (14.3% and 13.7% vs. 8.5%) and preterm birth (12.2% and 12% vs. 6.6%).

Women who used both cannabis and nicotine in pregnancy, compared with nonusers, had increased risks for infant death (adjusted RR = 2.18; 95% CI, 1.82-2.62), neonatal death (aRR = 1.76; 95% CI, 1.36-2.28), small for gestational age (aRR = 1.94; 95% CI, 1.86-2.02) and preterm birth (aRR = 1.83; 95% CI, 1.75-1.91).

In addition, researchers observed higher rates of severe maternal morbidity among women who used cannabis alone (aRR = 1.33; 95% CI, 1.22-1.45), nicotine alone (aRR = 1.42; 95% CI, 1.34-1.5) and both cannabis and nicotine (aRR = 1.46; 95% CI, 1.29-1.64) compared with nonusers (2.3%, 2.1% and 2.6% vs. 1.3%; P < .001).

“Although the goal is abstinence from both cannabis and nicotine products in pregnancy, for patients who are unable to achieve this, our study suggests that at least cessation of one substance would still be beneficial and may help inform public health policy and clinician counseling,” the researchers wrote. “This underscores the urgent need for further studies to characterize the impact of prenatal cannabis and nicotine product co-exposure, especially the influence of potency, frequency and timing on short- and long-term maternal and offspring outcomes to better educate pregnant individuals on the potential harms of use."