Changes in methadone maintenance therapy during and after pregnancy

ObjectiveThe aim of this study is to better understand anticipated changes in daily methadone doses as a guide for prescription during pregnancy.MethodsThis retrospective case series involved a single cohort longitudinal design of 139 consecutively chosen women who began methadone therapy before 26 completed gestational weeks. Changes in the single daily dose were based on a standard opiate withdrawal scale and determined from early pregnancy until 6 weeks postpartum.ResultsAs gestation advanced, the methadone dose increased (86%) rather than remained the same (8%) or decreased (7%). This gradual increase in daily dose during pregnancy (mean increase = 24 mg, 95% confidence level = 20–28 mg) was statistically significant (p < .001) regardless of the initial maintenance dose. By the sixth postpartum week, most subjects (85%) took within 10 mg of their dose at delivery (mean change in dose = −4 mg, 95% confidence interval = −6 to −2 mg).ConclusionsDaily doses of methadone increased until the third trimester, then remained essentially unchanged through the sixth postpartum week.