Opioid use during pregnancy: a population-based cohort study

Abstract

Background:Opioid use has increased dramatically in North America. The safety of opioids in pregnancy is uncertain, but they are associated with several fetal abnormalities and contribute to rising rates of neonatal abstinence syndrome. 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 opioid use did not decline during pregnancy. The increasing dosage and increased use of higher-potency opioids by pregnant women highlights the need for continued evaluation of and education about the benefits and risks of this practice. Abstract ResearchResearch CMAJ OPEN E518CMAJ OPEN, 5(2)

Opioid and Cannabis Use During Pregnancy and Breastfeeding in Relation to Sociodemographics and Mental Health Status: A Descriptive Study

“…Our prevalence estimate of opioid use during pregnancy (1.4%) is lower than the prevalence estimates by Falk et al [17] based on the percentage of women filling opioid prescriptions before and during pregnancy among a cohort of pregnant women in Manitoba. Falk et al [17] found that while almost 7% filled prescriptions for opioids in the 3 months before pregnancy, this declined to 4.2%, 3.0% and 2.9% in the first to third trimesters, respectively.…”

Use of opioids during pregnancy and effects of pregnancy outcomes

“…No differences were observed in the number of the purchases of opioids Previous studies, including both primiparous and multiparous women, have shown a wide range in the prevalence of opioid use during pregnancy; varying from 22% in southern parts of the United States to 6% in Norway and 5% in Sweden. 7,[9][10][11]14 Our study finding that 5% of primiparous Finnish women used opioid drugs during pregnancy is consistent with previous Scandinavian studies. 7,11 When focusing upon the time periods of the purchases of opioids, the study findings have been inconsistent.…”

“…However, no reduction was reported when morphine equivalent units were used to measure the use of opioids. 10 A Norwegian study reported less opioids purchases as pregnancy progressed, 11 while Swedish and US studies reported the opposite. 4,7,9 Codeine was the most commonly used opioid among pregnant Finnish primiparous women; 96% of women who used opioids used codeine.…”

“…This result is in an agreement with several previous studies. 4,10,11 However, in the United States, in pregnant women, hydrocodone and codeine are used equally common. 8,9 In some countries, including Finland, hydrocodone is not available and it is classified…”

“…4,8 Globally, the most commonly used opioids during pregnancy are hydrocodone and codeine. 4,[8][9][10][11] Several studies have shown that the use of opioids during pregnancy increases the risk for birth abnormalities such as neural tube defects, gastroschisis, congenital heart defects, clubfoot, and neonatal abstinence syndrome. 8,[12][13][14] However, data on use of opioids during pregnancy and delivery outcomes is scarce.…”