///2019 Abstract Details
2019 Abstract Details2019-07-13T07:45:15-05:00

Prescription Opioid Use After Vaginal Delivery and Subsequent Persistent Opioid Use and Misuse

Abstract Number: BP-01
Abstract Type: Original Research

Brian T Bateman MD, MSc1 ; Yanmin Zhu PhD2; Loreen Staub MD3; Sonia Hernandez-Diaz MD, DrPH4; Krista F Huybrechts MS, PhD5

Introduction: Prior studies show that approximately 30% of women in the United States fill an opioid prescription after vaginal delivery (1,2), making this a common source of exposure to opioids in young women. Limited evidence is available regarding the impact of prescription opioid use after vaginal delivery on the risk of subsequent persistent opioid use and misuse.

Methods: We assembled a nationwide cohort of Medicaid beneficiaries who delivered vaginally between 2009 and 2013 and who were not chronic opioid users or diagnosed with an opioid use disorder during pregnancy. We required continuous Medicaid enrollment from at least 90 days before to 365 days after vaginal delivery. We identified prescription opioid dispensings within 7 days of the date of delivery. Persistent opioid use (primary outcome) was defined as >=10 opioid fills or >120 days' supply dispensed from 30 to 365 days after the date of delivery. Newly recorded diagnoses of opioid use disorder (secondary outcome) were ascertained during the same interval.

We conducted logistic regression after propensity-score (PS) 1:1 matching to control for potentially confounding conditions including maternal demographics, comorbidities, and vaginal delivery complications. To control for potentially unmeasured confounders, we performed an instrumental variable analysis (IVA) using a 2-stage least squares approach. To define the instrument, facilities were ranked within region according to their opioid dispensing rate after vaginal delivery and divided into deciles (rate of opioid dispensing in the bottom decile was 4.5% vs. 76.6% in the top decile).

Results: Among 226,995 vaginal deliveries, 29.9% had an opioid dispensing within 7 days of delivery. Overall, 3,113 of the 67,954 (4.6%) prescription opioid exposed vs. 1,445 of the 159,041 (0.9%) unexposed met criteria for persistent opioid use during the year of follow-up, for an unadjusted odds ratio (OR) of 5.2 (95% CI, 4.9 - 5.6) and a risk difference (RD) of 3.7% (95% CI, 3.5% - 3.8%). After PS matching, the risk remained higher among the prescription opioid exposed, with an OR of 2.7 (95% CI, 2.5 - 3.0) and a RD of 2.4% (95% CI, 2.3%- 2.6%). This was confirmed by the IVA (pseudo R2=0.3) with a RD of 2.8% (95% CI, 2.5% - 3.1%).

For newly diagnosed opioid use disorder, the unadjusted OR associated with opioid exposure after delivery was 2.4 (95% CI, 2.2 - 2.5), which attenuated to 1.5 (95% CI, 1.4 - 1.6) after PS matching. The adjusted risk difference was 0.9% (95% CI, 0.7% - 1.0%) after PS matching and 2.1% (95% CI, 1.8% - 2.4%) using IVA.

Conclusions: Opioid exposure following vaginal delivery appears to be a trigger for future persistent opioid use and misuse, independent of confounding factors. Given this risk, prescription opioid use after vaginal deliveries should generally be avoided.

1. Obstet Gynecol. 2018 Aug;132(2):459-465.

2. Drug Alcohol Depend. 2018 Jul 1;188:288-294.

SOAP 2019