Treatment of Opioid Use Disorder in Pregnancy Improves Outcomes

Abstract

Source: Piske M, Homayra F, Min JE, et al. Opioid use disorder and perinatal outcomes. Pediatrics. 2021;148(4):e2021050279. doi: 10.1542/peds.2021-050279Investigators from multiple institutions in Canada conducted a retrospective study to evaluate perinatal outcomes in infants born to mothers with opioid use disorder (OUD). For the study, they linked multiple databases to identify mothers with OUD diagnosed before delivery or in the puerperium period with completed pregnancies between April 1, 2000 and March 31, 2019 in British Columbia, Canada. Data abstracted on mothers included age, parity, gestational age, receipt of opioid agonist treatment, timing of treatment (before pregnancy, during pregnancy but not until delivery, or until delivery), type of opioid agonist treatment (methadone, slow release oral morphine [SROM], buprenorphine/naloxone), use of other psychotropic drugs during pregnancy (selective serotonin reuptake inhibitors [SSRIs], benzodiazepines, antipsychotics, and stimulants), tobacco use, and alcohol use. Newborn outcomes included low birth weight (<2,500 g), prematurity (<37 weeks), and neonatal abstinence syndrome (NAS) diagnosis (based on ICD-9 and ICD-10 codes). Descriptive statistics were used to evaluate these outcomes and assess trends over the study period. Linear mixed effects models were used to compare outcomes in babies whose mothers used opioid agonist treatment until delivery and in those who discontinued treatment in pregnancy, and in mothers treated with buprenorphine/naloxone or SROM vs methadone. Models were adjusted for maternal age, parity, use of psychotropic drugs, and alcohol and tobacco use.A total of 4,574 women were diagnosed with OUD, with 6,693 deliveries and 6,720 live births during the study period. Opioid agonist treatment during pregnancy was documented for 2,824 deliveries (42%), and prescriptions for psychotropic drugs were identified during pregnancy in 2,684 (37%) deliveries. During the study period, the number of cases of OUD in pregnancy increased from 166 in 2000–2001 to 513 in 2018–2019. Rates of use of opioid agonist treatment remained stable during the treatment period; 94.7% of opioid agonist treatment was with methadone. Among the infants born to mothers with OUD, 16% were low birth weight, 24% were born premature, and 2,496 (36.8%) were diagnosed with NAS. In the multivariate models, continued opioid agonist treatment through delivery, compared to treatment discontinuation during pregnancy, was associated with an increased risk of NAS in the infant (odds ratio [OR], 4.7; 95% CI, 3.6, 6.1), but decreased risk of preterm birth (OR, 0.6; 95% CI, 0.4, 0.8) and low birth weight (OR, 0.4; 95% CI, 0.2, 0.7). Compared to methadone, treatment with buprenorphine/naloxone or SROM was associated with lower risks of preterm delivery (OR, 0.6; 95% CI, 0.3, 0.9), low birth weight (OR, 0.6; 95% CI, 0.4, 0.9) and NAS (OR, 0.6; 95% CI, 0.4, 0.9).The authors conclude the incidence of perinatal OUD in British Columbia more than tripled over a 20-year period.Dr Von Kohorn has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.The documented increases in OUD during pregnancy and NAS in Canada mirror the US experience, where a recent national estimate of OUD in pregnancy was 8.2 per 1,000 births, and NAS was 7.3 per 1,000 births.1 (See AAP Grand Rounds. 2018;39[4]:47.)2 The current investigators found a rate of prematurity of 24% among infants born to mothers with OUD, which is more than double the population rate in the US.3 In multivariate models the authors demonstrate that treatment with opioid agonists, particularly non-methadone medications, significantly and substantially was associated with a reduced chance of prematurity.Despite the increase in OUD during pregnancy, the results of the current study show that the proportion of pregnant women with OUD who receive treatment remains stable and low, with less than half receiving opioid agonist treatment. The results of prior studies have shown similarly poor rates of opioid agonist treatment, with even less behavioral therapy.4 One barrier to uptake or continuation of opioid agonist treatment during pregnancy has been doubt about the strength of the evidence for improved outcomes with opioid agonist treatment during pregnancy. The current study overcomes many limitations of prior studies, and the results substantiate the association of opioid agonist treatment for those with OUD in pregnancy with improved outcomes.The evidence presented reinforces the need to make opioid agonist therapy more accessible to pregnant women with OUD. Since more than 90% of participants in the current study also had a coexisting mental health and other substance use diagnosis, interventions that increase holistic, multidisciplinary treatment may be optimal. Despite growing evidence for the superiority of buprenorphine and other non-methadone medications, methadone remains a common treatment.5 Improved access to non-methadone medications can help increase uptake.4OUD in pregnancy has increased substantially. Although treatment with opioid agonist medications improves outcomes, the proportion of those receiving treatment during pregnancy remains low.