Neurodevelopmental and Functional Outcomes Following In Utero Exposure to Antiseizure Medication: A Systematic Review

BACKGROUND AND OBJECTIVES

To undertake a systematic review of the available literature to examine the relationship between prenatal antiseizure medication (ASM) exposure and adverse postnatal neurodevelopmental outcomes, focusing on social, emotional, behavioral, and adaptive domains of human function, and the frequency of neurodevelopmental and psychiatric disorders in ASM-exposed offspring.

METHODS

Electronic searches of MEDLINE, PsychINFO, and EMBASE were conducted and limited to studies published between 1990 and 2023 in English. Studies were eligible if they prospectively or retrospectively reported neurodevelopmental outcomes of ASM-exposed offspring. The Newcastle-Ottawa scale was used to conduct methodologic quality assessments of included studies, and a narrative synthesis integrated the review findings.

RESULTS

Forty-three studies were included. Valproate has been consistently associated with a 2- to 4-fold increased risk of autism spectrum disorder (ASD), 2- to 5-fold increased risk of intellectual disability (ID), and poor adaptive functioning. Growing evidence indicates that topiramate is associated with a 2-fold increased risk of ASD and 3- to 4-fold increased risk of ID. The risks of adverse neurodevelopmental outcomes for valproate and topiramate seem to be dose dependent. Phenobarbital has been suggested to be associated with deleterious neurodevelopmental effects, but data are limited. Levetiracetam has recently been linked with an increased risk of attention deficit hyperactivity disorder and anxiety disorders in a single study. Carbamazepine has been associated with variable neurodevelopmental outcomes. Lamotrigine seems to be "safe" in terms of postnatal neurodevelopment. Data for oxcarbazepine, phenytoin, and clonazepam are limited but seem to have little-to-no risk of adverse outcomes. Evidence for the remaining ASMs, including gabapentin, pregabalin, lacosamide, zonisamide, clobazam, perampanel, ethosuximide, or brivaracetam, is lacking. Several methodologic limitations impeded data synthesis, including heterogeneity in outcome measures and small samples of monotherapy exposures.

DISCUSSION

The findings of this review support the conclusion that valproate and topiramate use during pregnancy is associated with a significantly increased risk of neurodevelopmental effects on the fetus. Apart from lamotrigine, which seems to be free of adverse neurodevelopmental effects, data for the other ASMs are mixed or inadequate to draw definite conclusions. Further research into the neurodevelopmental effects of prenatal exposure to ASMs, including most newer agents, is much needed.

Neurodevelopmental outcomes in children exposed to newer antiseizure medications: A systematic review

As prenatal exposure to certain older antiseizure medications (ASMs) has been linked with poorer neurodevelopmental outcomes in children, the use of newer ASMs throughout pregnancy has increased. The current review aimed to delineate the impact of in utero exposure to these newer ASMs on child neurodevelopment. A systematic search of MEDLINE, Embase, Web of Science, Cumulative Index to Nursing and Allied Health Literature Plus, and PsycINFO was conducted, limiting results to articles available in English and published after the year 2000. Studies investigating neurodevelopmental outcomes following in utero exposure to the following ASMs were eligible for inclusion in the review: eslicarbazepine, gabapentin, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, perampanel, topiramate, and zonisamide. Thirty-five publications were identified, and a narrative synthesis was undertaken. Methodological quality was variable, with distinct patterns of strengths/weaknesses attributable to design. Most studies examined lamotrigine exposure and reported nonsignificant effects on child neurodevelopment. Comparatively fewer high-quality studies were available for levetiracetam, limiting conclusions regarding findings to date. Data for topiramate, gabapentin, and oxcarbazepine were so limited that firm conclusions could not be drawn. Concerningly, no studies investigated eslicarbazepine, lacosamide, perampanel, or zonisamide. Exposure to certain newer ASMs, such as lamotrigine and levetiracetam, does not thus far appear to impact certain aspects of neurodevelopment, but further delineation across the different neurodevelopmental domains and dosage levels is required. A lack of data cannot be inferred to represent safety of newer ASMs, which are yet to be investigated.

Assessment of School-Aged Children of Mothers With Idiopathic Generalized Epilepsy

The aim is to examine the cognitive domains, behavioral domains, and electroencephalogram (EEG) findings in children of mothers with idiopathic generalized epilepsy who had been exposed to antiepileptic drugs (AEDs) in utero. Forty school-aged children born to 23 mothers with idiopathic generalized epilepsy were compared with 40 healthy children born to 34 healthy mothers. Stanford-Binet Intelligence Scale was applied to all children to assess their cognitive functions. Child Behavior Checklist was used to assess their behavioral characteristics. EEG was done for the epileptic mothers and their children. Children exposed to AEDs showed significantly lower scores in the verbal reasoning, visual reasoning, and global intelligence quotient (IQ). There was a significantly positive correlation between children's global IQ and maternal global IQ. Multiple regression analysis showed that in utero exposure to valproate and maternal IQ were the most independent factors affecting children's IQ. EEG findings of participating children were normal. Exposure to valproic acid during fetal life and maternal IQ represent confounding factors affecting the IQ of children with in utero exposure to AEDs.

Mood stabilizers in pregnancy and child developmental outcomes: A systematic review

BACKGROUND

Research suggests that maintaining treatment during pregnancy for women with bipolar affective disorder reduces the risk of relapse. However, one of the key questions for women and clinicians during pregnancy is whether there are implications of exposure to mood stabilizers for longer term child development. Despite these concerns, there are few recent systematic reviews comparing the impact on child developmental outcomes for individual mood-stabilizing agents to inform clinical decisions.

OBJECTIVES

To examine the strengths and limitations of the existing data on child developmental outcomes following prenatal exposure to mood stabilizers and to explore whether there are any differences between agents for detrimental effects on child development.

METHOD

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a rigorous systematic search was carried out of four electronic databases from their respective years of inception to September 2016 to identify studies which examined the effects of mood stabilizers including sodium valproate, carbamazepine, lamotrigine, lithium and second-generation antipsychotics on child developmental outcomes.

RESULTS

We identified 15 studies for critical review. Of these, 10 examined antiepileptic drugs, 2 studied lithium and 3 studied second-generation antipsychotics. The most consistent finding was a dose-response relationship for valproate with higher doses associated with poorer global cognitive abilities compared to other antiepileptic drugs. The limited data available for lithium found no adverse neurodevelopmental outcomes. The limited second-generation antipsychotic studies included a report of a transient early neurodevelopmental delay which resolved by 12 months of age.

CONCLUSION

This review found higher neurodevelopmental risk with valproate. While the existing data on lithium and second-generation antipsychotics are reassuring, these data are both limited and lower quality, indicating that further research is required. The information from this review is relevant for patients and clinicians to influence choice of mood-stabilizing agent in childbearing women. This must be balanced against the known risks associated with untreated bipolar affective disorder.

Teratogenicity of Antiepileptic Drugs

OBJECTIVE

Antiepileptic drugs (AED) have chronic teratogenic effects, the most common of which are congenital heart disease, cleft lip/palate, urogenital and neural tube defects. The aim of our study is to examine teratogenic effects of AED and the correlation between these malformations and AED in single or multiple pregnancies.

METHODS

This is a retrospective study of malformations in children born to mothers currently followed up by our outpatient clinics who used or discontinued AED during their pregnancy. Their children were then investigated using echocardiography, urinary ultrasound, cranial magnetic resonance image, and examined by geneticists and pediatric dentists.

RESULTS

One hundred and seventeen children were included in the study. Ninety one of these children were exposed to AED during pregnancy. The most commonly used AED were valproic acid and carbamazepine in monotherapy. The percentage of major anomaly was 6.8% in all children. Dysmorphic features and dental anomalies were observed more in children exposed especially to valproic acid. There were 26 mothers with two and four mothers with three pregnancies from the same fathers. No correlation was found between the distribution of malformations in recurring pregnancies and AED usage.

CONCLUSION

Our study has the highest number of dysmorphism examined in literature, found in all the children exposed to valproic acid, which may account for the higher rate of facial dysmorphism and dental anomalies. On lower doses of valproic acid, major malformations are not seen, although the risk increases with polytherapy. Our data also indicate possible effects of genetic and environmental factors on malformations.