USE OF GABAPENTIN IN PREGNANCY

Gabapentin is an antiepileptic drug indicated as monotherapy or adjunctive therapy in the treatment of partial seizures with or without secondary generalisation and for the treatment of peripheral neuropathic pain. It is also used off-licence for migraine prophylaxis and to ameliorate hot flushes in women receiving treatment for breast cancer.

The majority of the available epidemiological data relate to gabapentin use in pregnancy for the treatment of maternal epilepsy. A few case reports/series describe use of gabapentin in the treatment of neuropathic pain or hyperemesis gravidarum, but no epidemiological studies have assessed fetal outcomes following use in pregnancy for these maternal indications.

The available data do not provide robust evidence of an increased risk of congenital malformation overall, or for cardiac malformation/hypospadias specifically, following gabapentin exposure in pregnancy. However, the evidence is also too limited to definitively exclude a risk. Studies which assessed rates of miscarriage or intrauterine death following gabapentin exposure in pregnancy do not currently identify an increased risk of these outcomes. Conflicting results regarding a possible increased risk of preterm delivery and low birth weight have been described in a small number of studies, but these data may be confounded. Data relating to neurodevelopmental impairment are limited and conflicting, therefore further research on this subject is required before firm conclusions can be drawn.

Use of any centrally-acting drug throughout pregnancy or near delivery may be associated with withdrawal symptoms in the neonate and/or poor neonatal adaptation syndrome (PNAS). These symptoms are likely to be more severe in infants exposed in utero to more than one CNS acting drug. Delivery should be planned in a unit with neonatal intensive care facilities.

Gabapentin may impact upon maternal folate status. UK guidelines state that women who take any anti-epileptic medication should be prescribed high dose folic acid (5mg).

More research is required to define the pregnancy safety profile of gabapentin. Pregnant women and women of child bearing potential should be made aware of the lack of data for most pregnancy outcomes. Gabapentin should only be used during pregnancy where benefits of treatment are considered to outweigh any potential risks. In view of the limited human pregnancy data, close monitoring of mother and fetus should be considered with use of gabapentin in pregnancy. 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.