Prenatal exposure to valproate and risk of congenital malformations-Could we have known earlier?-A population-based cohort study

Sodium valproate effects on the morphological and neurobehavioral phenotype of zebrafish

The anticonvulsant sodium valproate (SV) is frequently administered as a medicament but bears several negative effects in case of exposure during development. We analyzed extensively these early development effects of using the zebrafish model. Zebrafish embryos were exposed as eggs to two sublethal concentrations of SV, 10 and 25 mg/L. A general embryo toxicity analysis revealed extended anomalies in the cardiovascular system, and in the craniofacial and the spinal skeleton, as well as high mortality, in the embryos exposed to SV. The teratogenic potential of SV was confirmed in hacthed larvae by morphometric and cartilage profile analysis. Last, neurobehavioral impairments due to SV were highlighted in subjects' activity, anxiety, response to stimulations, habituation learning, and daily synchronization of locomotor activity, overall mirroring typical phenotypes associated with autistic spectrum disorders. In conclusion, our results confirmed the presence of extended and multifaced impacts of exposure to SV during development.

Correlation of drug dose estimated from national prescription registers with mean blood level of antiseizure medication in pregnancy

PURPOSE

The purpose was to examine the correlation of antiseizure medication drug dose estimated from prescription fill records from prescription registers with blood levels during pregnancy.

METHODS

We conducted a Nation-wide study of mothers who gave birth in Denmark between 1 January 2014 and 31 December 2018 using data from Danish Prescription and Laboratory Registers. We identified mothers with blood level measurements of antiseizure medication. The main exposure was estimated antiseizure medication dosage estimated from pregnancy-filled prescriptions in the Danish Prescription Register. The main outcome was the correlation of estimated dose with mean blood level of antiseizure medication in pregnancy. For privacy reasons, the number of blood level measurement and prescription fills were rounded to nearest 10, but proportions reported as exact values.

RESULTS

Among 298 560 pregnancies, we identified pregnancies with recorded prescription fill from the prescription register for valproate (N = 90), lamotrigine (N = 1360), levetiracetam (N = 340), topiramate (N = 100), and carbamazepine (N = 60). In these pregnancies, blood level measurements were available in 50 (53%) pregnancies for valproate, 850 (62%) pregnancies for lamotrigine, 320 (93%) pregnancies for levetiracetam, 50 (68%) pregnancies for carbamazepine, and 40 (35%) pregnancies for topiramate. Pearsons's correlation coefficients for the correlation of estimated antiseizure medication dose with mean blood levels were 0.67 (p < 0.0001) for valproate, 0.63 (p < 0.0001) for lamotrigine, 0.63 (p < 0.0001) for levetiracetam, 0.76 (<0.0001) for carbamazepine and 0.89 (<0.0001) for topiramate.

CONCLUSIONS

Dose of antiseizure medication estimated from prescription fills was a good proxy for blood levels and thus for biological exposure in pregnancy, suggesting that administrative prescription fill records may be a valuable resource for estimating exposure to antiseizure medication in pregnancy.

Comparison of neurodevelopmental, educational and adult socioeconomic outcomes in offspring of women with and without epilepsy: A systematic review and meta-analysis

BACKGROUND

Adequate pre-pregnancy counselling and education planning are essential to improve outcomes for offspring of women with epilepsy (OWWE). The current systematic review and meta-analysis aimed to compare outcomes for OWWE and offspring of women without epilepsy (OWWoE).

METHODS

We conducted a systematic review and meta-analysis. We searched MEDLINE, EMBASE, CINAHL, PsycINFO (database inception-1st January 2023), OpenGrey, GoogleScholar, and hand-searched journals and reference lists of included studies to identify eligible studies. We placed no language restrictions and included observational studies concerning OWWE and OWWoE. We followed the PRIMSA checklist for abstracting data. The Newcastle-Ottawa Scale for risk of bias assessment was conducted independently by two authors with mediation by a third. We report pooled unadjusted odds ratios (OR) or mean differences (MD) with 95% confidence intervals (95CI) from random (I2>50%) or fixed (I2<50%) effects meta-analyses. Outcomes of interest included offspring autism, attention deficit/hyperactive disorder, intellectual disability, epilepsy, developmental disorder, intelligence, educational, and adulthood socioeconomic outcomes.

RESULTS

Of 10,928 articles identified, we included 21 in meta-analyses. OWWE had increased odds of autism (2 articles, 4,502,098 offspring) OR [95CI] 1·67 [1·54, 1·82], attention-deficit/hyperactivity disorder (3 articles, 957,581 offspring) 1·59 [1·44, 1·76], intellectual disability (2 articles, 4,501,786 children) 2·37 [2·13, 2·65], having special educational needs (3 articles, 1,308,919 children) 2·60 [1·07, 6·34]. OWWE had worse mean scores for full-scale intelligence (5 articles, 989 children) -6·05 [-10·31, -1·79]. No studies were identified that investigated adulthood socioeconomic outcomes.

CONCLUSIONS

Increased odds of poor outcomes are higher with greater anti-seizure medication burden including neurodevelopmental and educational outcomes. In fact, these two outcomes seem to be worse in OWWE compared to OWWoE, even if there was no ASM exposure during pregnancy, but further work is needed to take into account potential confounding factors.

Monotherapy treatment of epilepsy in pregnancy: congenital malformation outcomes in the child

BACKGROUND

Prenatal exposure to certain anti-seizure medications (ASMs) is associated with an increased risk of major congenital malformations (MCM). The majority of women with epilepsy continue taking ASMs throughout pregnancy and, therefore, information on the potential risks associated with ASM treatment is required.

OBJECTIVES

To assess the effects of prenatal exposure to ASMs on the prevalence of MCM in the child.

SEARCH METHODS

For the latest update of this review, we searched the following databases on 17 February 2022: Cochrane Register of Studies (CRS Web), MEDLINE (Ovid, 1946 to February 16, 2022), SCOPUS (1823 onwards), and ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP). No language restrictions were imposed.

SELECTION CRITERIA

We included prospective cohort controlled studies, cohort studies set within pregnancy registries, randomised controlled trials and epidemiological studies using routine health record data. Participants were women with epilepsy taking ASMs; the two control groups were women without epilepsy and untreated women with epilepsy.

DATA COLLECTION AND ANALYSIS

Five authors independently selected studies for inclusion. Eight authors completed data extraction and/or risk of bias assessments. The primary outcome was the presence of an MCM. Secondary outcomes included specific types of MCM. Where meta-analysis was not possible, we reviewed included studies narratively.

MAIN RESULTS

From 12,296 abstracts, we reviewed 283 full-text publications which identified 49 studies with 128 publications between them. Data from ASM-exposed pregnancies were more numerous for prospective cohort studies (n = 17,963), than data currently available for epidemiological health record studies (n = 7913). The MCM risk for children of women without epilepsy was 2.1% (95% CI 1.5 to 3.0) in cohort studies and 3.3% (95% CI 1.5 to 7.1) in health record studies. The known risk associated with sodium valproate exposure was clear across comparisons with a pooled prevalence of 9.8% (95% CI 8.1 to 11.9) from cohort data and 9.7% (95% CI 7.1 to 13.4) from routine health record studies. This was elevated across almost all comparisons to other monotherapy ASMs, with the absolute risk differences ranging from 5% to 9%. Multiple studies found that the MCM risk is dose-dependent. Children exposed to carbamazepine had an increased MCM prevalence in both cohort studies (4.7%, 95% CI 3.7 to 5.9) and routine health record studies (4.0%, 95% CI 2.9 to 5.4) which was significantly higher than that for the children born to women without epilepsy for both cohort (RR 2.30, 95% CI 1.47 to 3.59) and routine health record studies (RR 1.14, 95% CI 0.80 to 1.64); with similar significant results in comparison to the children of women with untreated epilepsy for both cohort studies (RR 1.44, 95% CI 1.05 to 1.96) and routine health record studies (RR 1.42, 95% CI 1.10 to 1.83). For phenobarbital exposure, the prevalence was 6.3% (95% CI 4.8 to 8.3) and 8.8% (95% CI 0.0 to 9277.0) from cohort and routine health record data, respectively. This increased risk was significant in comparison to the children of women without epilepsy (RR 3.22, 95% CI 1.84 to 5.65) and those born to women with untreated epilepsy (RR 1.64, 95% CI 0.94 to 2.83) in cohort studies; data from routine health record studies was limited. For phenytoin exposure, the prevalence of MCM was elevated for cohort study data (5.4%, 95% CI 3.6 to 8.1) and routine health record data (6.8%, 95% CI 0.1 to 701.2). The prevalence of MCM was higher for phenytoin-exposed children in comparison to children of women without epilepsy (RR 3.81, 95% CI 1.91 to 7.57) and the children of women with untreated epilepsy (RR 2.01. 95% CI 1.29 to 3.12); there were no data from routine health record studies. Pooled data from cohort studies indicated a significantly increased MCM risk for children exposed to lamotrigine in comparison to children born to women without epilepsy (RR 1.99, 95% CI 1.16 to 3.39); with a risk difference (RD) indicating a 1% increased risk of MCM (RD 0.01. 95% CI 0.00 to 0.03). This was not replicated in the comparison to the children of women with untreated epilepsy (RR 1.04, 95% CI 0.66 to 1.63), which contained the largest group of lamotrigine-exposed children (> 2700). Further, a non-significant difference was also found both in comparison to the children of women without epilepsy (RR 1.19, 95% CI 0.86 to 1.64) and children born to women with untreated epilepsy (RR 1.00, 95% CI 0.79 to 1.28) from routine data studies. For levetiracetam exposure, pooled data provided similar risk ratios to women without epilepsy in cohort (RR 2.20, 95% CI 0.98 to 4.93) and routine health record studies (RR 0.67, 95% CI 0.17 to 2.66). This was supported by the pooled results from both cohort (RR 0.71, 95% CI 0.39 to 1.28) and routine health record studies (RR 0.82, 95% CI 0.39 to 1.71) when comparisons were made to the offspring of women with untreated epilepsy. For topiramate, the prevalence of MCM was 3.9% (95% CI 2.3 to 6.5) from cohort study data and 4.1% (0.0 to 27,050.1) from routine health record studies. Risk ratios were significantly higher for children exposed to topiramate in comparison to the children of women without epilepsy in cohort studies (RR 4.07, 95% CI 1.64 to 10.14) but not in a smaller comparison to the children of women with untreated epilepsy (RR 1.37, 95% CI 0.57 to 3.27); few data are currently available from routine health record studies. Exposure in utero to topiramate was also associated with significantly higher RRs in comparison to other ASMs for oro-facial clefts. Data for all other ASMs were extremely limited. Given the observational designs, all studies were at high risk of certain biases, but the biases observed across primary data collection studies and secondary use of routine health records were different and were, in part, complementary. Biases were balanced across the ASMs investigated, and it is unlikely that the differential results observed across the ASMs are solely explained by these biases.

AUTHORS' CONCLUSIONS

Exposure in the womb to certain ASMs was associated with an increased risk of certain MCMs which, for many, is dose-dependent.

Effects of Maternal Use of Antiseizure Medications on Child Development

Most children born to women with epilepsy (WWE) are normal, but have increased risks for malformations and poor neuropsychological outcomes. Antiseizure medications (ASMs) are among the most commonly prescribed teratogenic medications in women of childbearing age. However, WWE typically cannot avoid using ASMs during pregnancy. Teratogenic risks vary across ASMs. Valproate poses a special risk for anatomic and behavioral teratogenic risks compared with other ASMs. The risks for many ASMs remain uncertain. Women of childbearing potential taking ASMs should be taking folic acid. Breastfeeding while taking ASMs seems safe. WWE should receive informed consent outlining risks before conception.

Valproate Restrictions in Sweden and Norway: Online survey suggests implementation deficit

OBJECTIVES

To assess knowledge among neurologists in Sweden and Norway on the restrictions issued by the European Medicines Agency (EMA) regarding use of valproic acid (VPA) to female patients of childbearing potential, their use of the pregnancy prevention programme and their VPA prescription habits.

MATERIALS & METHODS

We conducted an online survey from May through September 2021 inviting neurologists in Sweden and Norway to participate. The questions assessed familiarity with the EMA restrictions, knowledge and use of the information material issued by Market Authorization Holders (MAH) of VPA, and experience of VPA prescriptions to women of childbearing age in the last 2 years.

RESULTS

The survey received 202 responses (response rate ≈ 20%). Of the responders, 51% were well acquainted with the EMA restrictions, and 49% were aware of the MAH-issued educational material. Eighty-eight (44%) had prescribed VPA to women of childbearing age in the last 2 years, and of these, only a small minority (n = 13) regularly used the information brochure for patients, and even fewer (n = 8) the VPA risk acknowledgement forms.

CONCLUSIONS

We found limited penetrance of the new EMA restrictions on VPA use as well as limited acceptance and use among prescribers of the current company-issued information material and risk acknowledgment forms. More information campaigns and closer collaboration with treating physicians are likely needed.

Maternal Epilepsy and Long-term Offspring Mortality - a Nationwide Cohort Study

Objective

We examined how maternal epilepsy and use of antiseizure medications in pregnancy was associated with offspring mortality.

Methods

This population‐based cohort study included all live‐ and stillborn singletons in Denmark between 1981 and 2016. We used nation‐wide registers to retrieve information on pregnancy characteristics, epilepsy diagnoses, use of antiseizure medications, and mortality. Adjusted mortality rate ratios (MRR) were estimated using log‐linear Poisson regression.

Results

The cohort consisted of 1,862,474 children. In total, 12,026 live‐born children died during follow‐up, of whom 170 (1.4%) were offspring of mothers with epilepsy. Overall mortality was increased in offspring of mothers with epilepsy compared to offspring of mothers without epilepsy (MRR = 1.46, 95% CI: 1.23–1.71), driven by an excess mortality only in the first year of life. Mortality was increased for natural deaths (MRR = 1.50, 95% CI: 1.25–1.78) but not from unnatural deaths (MRR = 1.38, 95% CI: 0.84–2.14), and only in offspring of women with epilepsy who used antiseizure medications during pregnancy (MRR = 1.51, 95% CI: 1.00–2.17), but not in offspring of women with epilepsy who did not use antiseizure medications while pregnant (MRR = 0.97, 95% CI: 0.69–1.31). When analyses were restricted to children born from 2000 and onwards, the excess mortality that was observed in the first year of life among children of mothers with epilepsy, was no longer evident.

Interpretation

During the 1981 to 1999 epoch, offspring of women with epilepsy were at increased risk of dying in the first year of life. However, this risk did not extend to children born after 2000. Future retrospective studies of the effects of maternal epilepsy on the health of the offspring should take this difference into account. ANN NEUROL 2022;91:455–465