Opioid use during pregnancy: a population-based cohort study.

We examined opioid use before and during pregnancy in a complete population-based cohort. METHODS: We examined opioid use in a cohort of all pregnant women in Manitoba, Canada, from 2001 to 2013. Opioid use was defined by prescriptions for opioids, converted to oral morphine equivalents (MEQ), during the 3 months before pregnancy and for each trimester. Given that the exposure per person may vary (because not all women complete all time periods), we determined a weighted number of pregnancies in each period. RESULTS: During the study period, 174 848 completed pregnancies were eligible for analysis (173 680 live births and 1168 stillbirths and intrauterine deaths), which represented a weighted value of 175 174 pregnancies. Among these pregnancies, 6.7% of the women filled opioid prescriptions in the 3 months before pregnancy. Use declined to 4.2% during the first trimester and further declined to 3.0% and 2.9% in the second and third trimesters, respectively. Over the study period, there was a modest increase in opioid use overall (from 7.3% to 7.7%). MEQ did not decline during pregnancy, and the mean MEQ increased significantly over the study period (from 284 mg to 1218 mg). Prescriptions for codeine were filled by 96.9% of the users, accounting for 66.2% of MEQ. INTERPRETATION: Although many of the women using opioids before pregnancy discontinued or reduced use of these drugs during pregnancy, the volume of opioids consumed by those who continued o...
Source: cmaj - Category: General Medicine Authors: Tags: CMAJ Open Source Type: research