[Malformations and fetal death in the Spanish antiepileptic drug and pregnancy registry: results at 6 years]

Abstract

Introduction: Pregnancy registries provide trustworthy information about the risks associated to antiepileptic drugs (AEDs). EURAP is a Prospective International Registry which include patients who takes AEDs at the time of conception. The data of the Spanish centers which are contributing to EURAP reflects the reality of our milieu.

Objectives: To study the incidence of major congenital malformations (MCM) /and/or fetal-perinatal death (MFP) and determine his relationship to AEDs in the Spanish EURAP registry.

Methods: After informed consent, patients were included in the prospective Registry and evaluated: at the beginning, at the end of the second and third trimester, after delivery and one year after birth. A variety of variables were collected: demographic, type of epilepsy, frequency of seizures during pregnancy, AEDs and dose, potential toxics, folate use and dose, obstetric complications and information of the newborn. After 6 years of recruitment (June 2001-October 2007) we analyzed the results of this Registry in Spain with special attention on the incidence of major congenital malformations and foetal-perinatal death.

Results: Of a whole of 540 cases included in the Registry, 490 were prospective (included before the 16th week), of these we had complete information in 368 cases. Major congenital maLformations were present in 5% (n=13) of the child exposed to monotherapy and 12% (n=6) of those exposed to polytherapy (p=0.08). All polytherapy combinations with MCM, contained valproate. Of the variables analyzed only low weight at birth and the AEDs used showed statistically significant association with MCM and MFP. The percentage of MCM was superior for valproate, particularly at doses equal or superior of 1000 mg/day (16%), although differences were not statistically significant. The majority of ours patients were on monotherapy (83%) with AEDs at low doses and were taking 5 mg of folate.

Conclusions: Patients on polytherapy, particularly those with valproate in combination present more risk of MCM. For monotherapy exposures only weight at birth and the AEDs used have association statistically significant with MC/MFP. Valproate in our series presents more risk than lamotrigine and does not show differences with regard to carbamazepine.