Population studies have reported odds ratios for certain congenital anomalies associated with fetal opioid exposure in the range of which?

• A. 1.0 to 1.5
• B. 1.8 to 2.7
• C. 3 to 4
• D. 5 to 6

Answer: (B)

When looking at how fetal opioid exposure relates to congenital anomalies, studies that analyze populations often report odds ratios in the range of roughly 1.8 to 2.7. This means the odds of having a congenital anomaly are about 80% to 170% higher in opioid-exposed pregnancies compared with unexposed pregnancies. It signals a real but modest to moderate increase in risk rather than a dramatic one.

Interpreting these numbers, an odds ratio above 1 suggests increased risk, and because congenital anomalies are relatively rare, the odds ratio closely approximates the relative risk. Keep in mind that the exact figure varies by the specific anomaly and study design, and potential confounders—like tobacco or other substance use, SES, and prenatal care—can influence the magnitude.

Ranges like 1.0 to 1.5 would indicate only a small increase, while much higher ranges (3–4 or 5–6) imply a stronger association that isn’t as commonly observed across studies. Therefore, the range 1.8 to 2.7 best fits what population studies have reported for fetal opioid exposure.