USE OF BACLOFEN IN PREGNANCY

Baclofen is a gamma-aminobutyric acid (GABA) agonist licensed for oral or intrathecal administration to alleviate spasticity of voluntary muscle in patients with multiple sclerosis, spinal cord lesions, cerebral palsy, cerebrovascular accidents, traumatic head injury, and meningitis.

Data on the use of baclofen in human pregnancy are derived from one small cohort study (presented in abstract only), case reports and two small case series (one presented only in abstract) and, as such, are too limited to accurately assess risks to the infant or pregnancy. An increased risk of congenital malformation following in utero exposure has been reported by a small cohort study; however, no pattern of defects was observed, and due to the small numbers of cases, consequent wide confidence intervals and lack of consideration of the impact of concomitant risk factors, the conclusions that can be drawn from this single study are limited. No evidence of an increased risk of miscarriage was provided from a small cohort study. There are insufficient data to assess the risk of intrauterine death, low birth weight, preterm delivery and adverse neurodevelopmental effects.

Neonatal withdrawal has been reported following maternal use of oral baclofen. Delivery in a unit with adequate neonatal facilities is therefore advised if maternal use has occurred in the weeks prior to delivery.

Due to the lack of safety data, the need for additional fetal monitoring needs to be considered on a case-by-case basis. Other risk factors may also be present in individual cases which may independently increase the risk of adverse pregnancy outcome. Clinicians are reminded of the importance of consideration of such factors when performing case-specific risk assessments.