All you need to read in the other general journalsBMJ 2009; 338 doi: https://doi.org/10.1136/bmj.b1617 (Published 21 April 2009) Cite this as: BMJ 2009;338:b1617
Valproate reduces IQ in offspring
Valproate shouldn’t be used as the drug of first choice in women with epilepsy who may become pregnant. A multicentre prospective cohort study enrolled 303 pregnant women with epilepsy who were taking monotherapy with carbamazepine, lamotrigine, phenytoin, or valproate. At 3 years of age, children born to these women were assessed for cognitive outcomes by blinded assessors who used the mental developmental index of the Bayley scales of infant development (2nd edition) or differential ability scales. Results were adjusted for mother’s IQ and age, dose of antiepileptic drug, gestational age at birth, and maternal use of folate before conception⇑.
Mean IQs in children whose mothers were taking lamotrigine, phenytoin, carbamazepine, or valproate during pregnancy were 101, 99, 98, and 92, respectively. In children exposed in utero to valproate, IQ was on average 9 points lower than in children exposed to lamotrigine (95% CI 3.1 to 14.6), 7 points lower than in children exposed to phenytoin (0.2 to 14.0), and 6 points lower than in children exposed to carbamazepine (0.6 to 12.0). The association between exposure to valproate and IQ was dose dependent, and children’s IQs were significantly related to maternal IQs in all children except for those exposed to valproate.
For some women, valproate is the only drug that controls seizures. These women should be informed of the potential risks associated with the use of this drug in pregnancy. But the authors say that women taking valproate who are already pregnant should not stop taking the drug without consulting their doctor, because this could lead to seizures and serious consequences for both the woman and her fetus.