CONTEXT
Opioid use and abuse have increased dramatically in recent years, particularly among women.
OBJECTIVES
We conducted a systematic review to evaluate the association between prenatal opioid use and congenital malformations.
DATA SOURCES
We searched Medline and Embase for studies published from 1946 to 2016 and reviewed reference lists to identify additional relevant studies.
STUDY SELECTION
We included studies that were full-text journal articles and reported the results of original epidemiologic research on prenatal opioid exposure and congenital malformations. We assessed study eligibility in multiple phases using a standardized, duplicate review process.
DATA EXTRACTION
Data on study characteristics, opioid exposure, timing of exposure during pregnancy, congenital malformations (collectively or as individual subtypes), length of follow-up, and main findings were extracted from eligible studies.
RESULTS
Of the 68 studies that met our inclusion criteria, 46 had an unexposed comparison group; of those, 30 performed statistical tests to measure associations between maternal opioid use during pregnancy and congenital malformations. Seventeen of these (10 of 12 case-control and 7 of 18 cohort studies) documented statistically significant positive associations. Among the case-control studies, associations with oral clefts and ventricular septal defects/atrial septal defects were the most frequently reported specific malformations. Among the cohort studies, clubfoot was the most frequently reported specific malformation.
LIMITATIONS
Variabilities in study design, poor study quality, and weaknesses with outcome and exposure measurement.
CONCLUSIONS
Uncertainty remains regarding the teratogenicity of opioids; a careful assessment of risks and benefits is warranted when considering opioid treatment for women of reproductive age.