Opioid analgesic use in first trimester increases risk of cleft palate

Abstract

Use of prescription opioid analgesics during the first trimester of pregnancy appears to increase the risk of cleft palate, but does not increase the risk of other congenital abnormalities, according to findings of a US study published in the BMJ. Nationwide Medicaid Analytic eXtract (MAX) data on 1 602 580 US Medicaid beneficiaries who were pregnant between 2000 and 2014, and IBM Health MarketScan Research Database (MarketScan) data on 1 177 676 commercially insured beneficiaries who were pregnant between 2003 and 2015, were used to investigate whether prescription opioid exposure during the first trimester increased the risk of congenital abnormalities. Opioid analgesics were dispensed for 4.4% of publicly insured and 1.1% of commercially insured pregnant women during the first trimester. The overall risk of congenital abnormalities was 41 per 1000 opioid-exposed pregnancies versus 32 per 1000 unexposed pregnancies in the MAX cohort, and 42 per 1000 versus 37 per 1000, respectively, in the MarketScan cohort. There were small increases in the pooled risks of overall congenital abnormalities (adjusted relative risk [aRR] 1.06; 95% CI 1.02, 1.10) and congenital heart defects (aRR 1.09; 95% CI 1.00, 1.18). Pooled estimates showed no significant increases in the risks of ventricular septal defect, atrial septal defect/patent foramen ovale, neural tube defect, clubfoot or oral cleft, but a significantly increased risk of cleft palate (aRR 1.62; 95% CI 1.23, 2.14). Overall, our findings suggest that prescription opioids used in early pregnancy are not associated with a substantial increase in risk for most of the malformation types considered, although clinicians should be aware of the potential for a small increase in the risk of oral clefts and counsel patients about this risk, said the authors.