The prevalence of neurodevelopmental disorders in children prenatally exposed to antiepileptic drugs.

The aim of this study was to compare the prevalence of diagnosed neurodevelopmental disorders in children exposed, in utero, to different antiepileptic drug treatments. A prospective cohort of women with epilepsy and a control group of women without epilepsy were recruited from antenatal clinics. The children of this cohort were followed longitudinally until 6 years of age (n=415). Diagnosis of a neurodevelopmental disorder was made independently of the research team. Multiple logistic regression analysis revealed an increase in risk of neurodevelopmental disorders in children exposed to monotherapy sodium valproate (VPA) (6/50, 12.0%; aOR 6.05, 95%CI 1.65 to 24.53, p=0.007) and in those exposed to polytherapy with sodium VPA (3/20, 15.0%; aOR 9.97, 95% CI 1.82 to 49.40, p=0.005) compared with control children (4/214; 1.87%). Autistic spectrum disorder was the most frequent diagnosis. No significant increase was found among children exposed to carbamazepine (1/50) or lamotrigine (2/30). An accumulation of evidence demonstrates that the risks associated with prenatal sodium VPA exposure include an increased prevalence of neurodevelopmental disorders. Whether such disorders are discrete or represent the severe end of a continuum of altered neurodevelopmental functioning requires further investigation. Replication and extension of this research is required to investigate the mechanism(s) underpinning the relationship. Finally, the increased likelihood of neurodevelopmental disorders should be communicated to women for whom sodium VPA is a treatment option.

Early cognitive development in children born to women with epilepsy: a prospective report.

PURPOSE: In this prospective study the early cognitive development of children born to women with epilepsy (n = 198) was assessed and compared to a group of children representative of the general population (n = 230). METHODS: The children were assessed when younger than the age of 2 years using the Griffiths Mental Development Scales, either in their local participating hospital or in their home. The assessments were completed by an assessor who was blinded to whether the child's mother had epilepsy and to antiepileptic drug type. RESULTS: Children exposed to sodium valproate had a statistically significant increased risk of delayed early development in comparison to the control children. Linear regression analysis showed a statistically significant effect of sodium valproate exposure on the child's overall developmental level that was not accounted for by confounding variables. Delayed early development is also noted for children within an ad hoc group of less commonly utilized antiepileptic drugs, although conclusions cannot be drawn due to the size of this group (n = 13). Children exposed to either carbamazepine or lamotrigine in utero did not differ significantly in their overall developmental ability. Differences noted in specific developmental areas for these two groups were not statistically significant after the control for confounders such as socioeconomic status and maternal IQ. DISCUSSION: Women with epilepsy should be informed of the risks posed to their potential offspring prior to pregnancy to allow for informed decisions regarding treatment. Children exposed in utero to antiepileptic drugs should be monitored throughout childhood to allow for early intervention when necessary.

IQ at 6 years after in utero exposure to antiepileptic drugs: a controlled cohort study.

OBJECTIVE: To delineate the risk to child IQ associated with frequently prescribed antiepileptic drugs. METHODS: Children born to women with epilepsy (n = 243) and women without epilepsy (n = 287) were recruited during pregnancy and followed prospectively. Of these, 408 were blindly assessed at 6 years of age. Maternal and child demographics were collected and entered into statistical models. RESULTS: The adjusted mean IQ was 9.7 points lower (95% confidence interval [CI] -4.9 to -14.6; p < 0.001) for children exposed to high-dose (>800 mg daily) valproate, with a similar significant effect observed for the verbal, nonverbal, and spatial subscales. Children exposed to high-dose valproate had an 8-fold increased need of educational intervention relative to control children (adjusted relative risk, 95% CI 8.0, 2.5-19.7; p < 0.001). Valproate at doses <800 mg daily was not associated with reduced IQ, but was associated with impaired verbal abilities (-5.6, 95% CI -11.1 to -0.1; p = 0.04) and a 6-fold increase in educational intervention (95% CI 1.4-18.0; p = 0.01). In utero exposure to carbamazepine or lamotrigine did not have a significant effect on IQ, but carbamazepine was associated with reduced verbal abilities (-4.2, 95% CI -0.6 to -7.8; p = 0.02) and increased frequency of IQ <85. CONCLUSIONS: Consistent with data from younger cohorts, school-aged children exposed to valproate at maternal doses more than 800 mg daily continue to experience significantly poorer cognitive development than control children or children exposed to lamotrigine and carbamazepine.

Outcome of pregnancy in women attending an outpatient epilepsy clinic: adverse features associated with higher doses of sodium valproate.

The risk of an adverse outcome to pregnancy is increased in women with epilepsy. This is partly attributable to antiepileptic drugs. Guidelines for the management of pregnancy in women with epilepsy generally advise against polytherapy but make no distinction between the risks of different drugs. Several recent studies have however shown greater risk of adverse outcome in offspring exposed to sodium valproate in utero, particularly at higher doses. The outcome of pregnancy was monitored to identify antiepileptic drug treatment associated with a poor outcome in a mainly prospective study of women attending an outpatient clinic. From January 1990 to December 1999 all 69 pregnancies in women referred to the clinic were monitored. Drug treatments and other risk factors were recorded. In each child dysmorphic features, developmental delay and structural anomalies were assessed and graded. Data were analysed for drug- and dosage-dependent differences in outcome. In each assessment area a positive association between adverse outcome and dose was found for sodium valproate but not for carbamazepine. Severe adverse outcomes were found only in children exposed to sodium valproate at maternal doses above 1000 mg per day.