Trends and adverse pregnancy and birth outcomes associated with stimulant-related disorder diagnosis

Background and aims

Stimulant-related disorders (SRD), or the continued misuse of illicit or prescribed stimulants, during pregnancy can have adverse health effects for mothers and infants. This study aimed to measure prevalence and trends of SRD diagnosis in pregnancy, and associations between SRD diagnosis and adverse maternal and infant health outcomes, among pregnant individuals in California.

Design

Retrospective cohort study.

Setting

California, USA.

Participants

Pregnant individuals from the Study of Outcomes in Mothers and Infants (SOMI) with singleton live births between 2012 and 2020 (n = 3 740 079).

Measurements

SRD diagnosis (excluding cocaine) and maternal (gestational diabetes, gestational hypertension [gHTN], severe maternal morbidity [SMM]) and infant (very preterm birth [gestational age <32 weeks], preterm birth [gestational age 32–37 weeks], neonatal intensive care unit [NICU] admission, small for gestational age [SGA]) outcomes were classified using International Classification of Disease (ICD) codes and vital statistics. Risk ratios were estimated with modified Poisson log linear regression that accounted for sibling pregnancies. Covariates included maternal sociodemographic characteristics, mental and physical health problems, nicotine use and co-occurrence of other diagnosed substance use disorders. Bias analyses were conducted to address unmeasured confounding and exposure misclassification.

Findings

SRD diagnosis among pregnant individuals increased from 2012 to 2020 (554 to 748 per 100 000 births). SRD diagnosis was associated with an increased risk of SMM (adjusted risk ratio [aRR] = 2.3; 95% confidence interval [CI] = 2.2–2.5), gHTN (aRR = 1.8; 95% CI = 1.7–1.9), very preterm birth (aRR = 2.2, 95% CI = 2.0–2.5), preterm birth (aRR = 2.1, 95% CI = 2.1–2.2) and NICU admission (aRR = 2.0, 95%CI = 1.9–2.0), and a decreased risk of gestational diabetes (aRR = 0.8; 95% CI = 0.8–0.9). SRD diagnosis was not associated with infants born SGA. Findings were generally robust to unmeasured confounding and misclassification of diagnosis.

Conclusions

Stimulant-related disorder diagnosis during pregnancy appears to be associated with an increased risk for select adverse maternal and infant health outcomes including severe maternal morbidity, gestational hypertension, very preterm birth, preterm birth and neonatal intensive care unit admission.