(112) Gabapentin use during pregnancy and adverse neonatal birth outcomes: a population-based cohort study

Publication Number: 1107

Background: Gabapentin is a new-generation antiseizure medication approved for epilepsy. Due to the perceived safety in pregnancy and efficacy in reducing pain, there has been an increase in the off-label use of gabapentin.

Objectives: We aim to study whether the association between gabapentin treatment during pregnancy and adverse neonatal outcomes differs among all pregnant people, pregnant people with epilepsy (PPWE), and pregnant people without epilepsy (PPWOE).

Methods: We conducted a population-based cohort study among pregnant people in Manitoba, Canada from 1998 to 2019. We examined the association between gabapentin exposure in-utero and the risk of small for gestational age (SGA), low birth weight (LBW), preterm birth, NICU admissions, maternal length of hospital stay (LOS)(>3days), infants LOS, infant mortality (≤27), neonatal mortality (≤365 days), and neonatal readmissions in all pregnant people, PPWE and PPWOE. Multivariate regression models were adjusted for socio-economic and clinical variables.

Results: Among 832 pregnant people exposed to gabapentin, we found a significant increased risk of LBW (aOR 1.85,95%CI 1.47-2.33), preterm birth(aOR 1.60,95%CI 1.30-1.97), NICU admissions (aOR 2.17,95%CI 1.79-2.62), mothers LOS (aOR 1.27,95%CI 1.09-1.49), infant LOS (aOR 2.06,95%CI 1.76-2.41) and a non-significant increase in SGA (aOR 1.10,95%CI 0.87-1.41), infant mortality (aOR 1.70,95%CI 0.74-3.89), neonatal mortality (aOR 1.42,95%CI 0.69-2.91) and neonatal readmissions (aOR 1.03,95%CI 0.71-1.49) when compared with gabapentin unexposed pregnant people. In PPWOE, we observed a significant increased risk of LBW (aOR 1.83,95%CI 1.45-2.23), preterm birth (aOR 1.57, 95%CI 1.27-1.94), NICU admissions (aOR 2.19,95%CI 1.80-2.65), LOS(mother) (aOR 1.23,95%CI 1.04-1.45), LOS (Infant)(aOR 2.05,95%CI 1.75-2.41) and a non-significant increase in SGA (aOR 1.09,95%CI 0.85-1.41), infants mortality (aOR 1.17,95%CI 0.51-2.64), neonatal mortality (aOR 1.50,95%CI 0.61-3.73) and neonatal readmissions (aOR 0.99,95%CI 0.68-1.44) when compared with gabapentin unexposed pregnant people. Similar trends of increased risk were found among PPWE, but none reached statistical significance.

Conclusions: Gabapentin exposure in pregnant people was associated with a significant increased risk of several adverse birth outcomes in infants. Clinicians should be aware of the benefits and potential risks of prescribing gabapentin during pregnancy specially for non-epilepsy indications. Larger studies among PPWE are recommended to better identify and separate the effect of gabapentin from underlying epilepsy.