Global Trends in Analgesic Opioid Use in Pregnancy: A Retrospective Cohort Study

Pain is common during pregnancy, yet there are few contemporary studies of opioid use in pregnancy. This study aimed to describe prescription analgesic opioid use during pregnancy across four regions: Oceania (New South Wales, Australia, and New Zealand), North America (Ontario, Canada, and United States), Northern Europe (Denmark, Finland, Iceland, Norway, Sweden, and United Kingdom), and East Asia (Hong Kong, South Korea, and Taiwan).

A common protocol was applied to population-based data to measure analgesic opioid dispensing or prescriptions during pregnancy before birth in 2000 to 2020. The populations captured included those with public and private insurance in the United States, a sample of primary care practices in the United Kingdom, and whole-of-population cohorts in the remainder of the locations. This study examined prevalence of use, defined as at least one dispensing or prescribing and estimated trends over time. Use by sociodemographic and pregnancy characteristics is described.

Among a total of 20,306,228 pregnancies, 1,115,853 (55 per 1,000) had at least one analgesic opioid dispensing or prescription, ranging from 4 per 1,000 in the United Kingdom to 191 per 1,000 in the U.S. publicly insured population. The greatest relative decrease in prevalence was observed in Hong Kong (prevalence ratio, 0.2; 95% CI, 0.1 to 0.2 between 2005 and 2020), and the greatest increase was in Iceland (prevalence ratio, 4.4; 95% CI, 3.7 to 5.2 between 2004 and 2017). Codeine and tramadol were among the three most prevalent opioids in most populations. In a sensitivity analysis defining opioid use as two or more opioid -dispensing or -prescribing events, the prevalence of opioid use across populations was 17 per 1,000.

In this large multinational study, wide global variation in the prevalence of analgesic opioid use in pregnancy was observed, yet patterns of use by sociodemographic and pregnancy characteristics were relatively consistent. Analgesic opioid use remained stable or downward trending over time in most, but not all, countries.