Person:

Hernandez-Diaz, Sonia

Objective: To provide absolute and relative risk estimates of neonatal abstinence syndrome (NAS) based on duration and timing of prescription opioid use during pregnancy in the presence or absence of additional NAS risk factors of history of opioid misuse or dependence, misuse of other substances, non-opioid psychotropic drug use, and smoking. Design: Observational cohort study. Setting: Medicaid data from 46 US states. Participants: Pregnant women filling at least one prescription for an opioid analgesic at any time during pregnancy for whom opioid exposure characteristics including duration of therapy: short term (<30 days) or long term (≥30 days); timing of use: early use (only in the first two trimesters) or late use (extending into the third trimester); and cumulative dose (in morphine equivalent milligrams) were assessed. Main outcome measure Diagnosis of NAS in liveborn infants. Results: 1705 cases of NAS were identified among 290 605 pregnant women filling opioid prescriptions, corresponding to an absolute risk of 5.9 per 1000 deliveries (95% confidence interval 5.6 to 6.2). Long term opioid use during pregnancy resulted in higher absolute risk of NAS per 1000 deliveries in the presence of additional risk factors of known opioid misuse (220.2 (200.8 to 241.0)), alcohol or other drug misuse (30.8 (26.1 to 36.0)), exposure to other psychotropic medications (13.1 (10.6 to 16.1)), and smoking (6.6 (4.3 to 9.6)) than in the absence of any of these risk factors (4.2 (3.3 to 5.4)). The corresponding risk estimates for short term use were 192.0 (175.8 to 209.3), 7.0 (6.0 to 8.2), 2.0 (1.5 to 2.6), 1.5 (1.0 to 2.0), and 0.7 (0.6 to 0.8) per 1000 deliveries, respectively. In propensity score matched analyses, long term prescription opioid use compared with short term use and late use compared with early use in pregnancy demonstrated greater risk of NAS (risk ratios 2.05 (95% confidence interval 1.81 to 2.33) and 1.24 (1.12 to 1.38), respectively). Conclusions: Use of prescription opioids during pregnancy is associated with a low absolute risk of NAS in the absence of additional risk factors. Long term use compared with short term use and late use compared with early use of prescription opioids are associated with increased NAS risk independent of additional risk factors.

Objective: To examine the teratogenic potential of statins. Design: Cohort study. Setting: United States. Participants: A cohort of 886 996 completed pregnancies linked to liveborn infants of women enrolled in Medicaid from 2000 to 2007. Methods: We examined the risk of major congenital malformations and organ specific malformations in offspring associated with maternal use of a statin in the first trimester. Propensity score based methods were used to control for potential confounders, including maternal demographic characteristics, obstetric and medical conditions, and use of other drugs. Results: 1152 (0.13%) women used a statin during the first trimester. In unadjusted analyses, the prevalence of malformations in the offspring of these women was 6.34% compared with 3.55% in those of women who did not use a statin in the first trimester (relative risk 1.79, 95% confidence interval 1.43 to 2.23). Controlling for confounders, particularly pre-existing diabetes, accounted for this increase in risk (1.07, 0.85 to 1.37). There were also no statistically significant increases in any of the organ specific malformations assessed after accounting for confounders. Results were similar across a range of sensitivity analyses. Conclusions: Our analysis did not find a significant teratogenic effect from maternal use of statins in the first trimester. However, these findings need to be replicated in other large studies, and the long term effects of in utero exposure to statins needs to be assessed, before use of statins in pregnancy can be considered safe.