Opioid analgesic use during pregnancy: a drug utilization cohort study in Catalonia

Background: The increasing use of opioids during pregnancy and their potential adverse effects on fetal development have raised public health concerns. This study aimed to investigate the opioid prescribing patterns among pregnant women in Catalonia, Spain. Materials and Methods: A retrospective drug-utilization study was conducted using the Information System for Research in Primary Care (SIDIAP) database, covering 75% of the Catalan population. Pregnancies in women aged 12-50 years between April 2011 and March 2020 were included. Opioid exposure was defined as at least one opioid prescription during pregnancy and was estimated through prevalence and cumulative incidence in pregnancy episodes and by trimester. We also examined pregnancy outcomes, exposure duration, and the use of non-opioid analgesics prior and concomitant to opioid therapy. Results: Among 41,398 pregnancies, 998 (2.41%) were exposed to prescribed opioids. Opioid prescribing increased over time, particularly since 2013 and mainly for non-cancer pain. Most exposures involved weak opioids (96.39%), with tramadol being the most frequently prescribed. Paracetamol use before or during opioid treatment was common, while NSAID use was less frequent. In over one-third of cases, opioid exposure exceeded 30 days, with even longer durations for those exposed to strong opioids. Conclusion: Our findings show a rise in opioid prescribing among pregnant women in Catalonia, primarily for non-cancer pain. Contradicting current guidelines, opioids were often prescribed without prior or concurrent NSAID use and with extended exposure durations. This underscores the need for pregnancy-specific pain management guidelines and stricter adherence to existing recommendations to minimize potential risks to the fetus.