Antiepileptic drug therapy in pregnancy II: fetal and neonatal exposure

Targeting adverse effects of antiseizure medication on offspring: current evidence and new strategies for safety

INTRODUCTION

For women with epilepsy of reproductive age, antiseizure medications (ASMs) are associated with an increased risk of offspring malformations. There are safety concerns for most anti-seizure medications in the perinatal period, and there is a clear need to identify safe medications. ASMs must transport through biological barriers to exert toxic effects on the fetus, and transporters play essential roles in trans-barrier drug transport. Therefore, it is vital to understand the distribution and properties of ASM-related transporters in biological barriers.

AREAS COVERED

This study reviews the structure, transporter distribution, and properties of the blood-brain, placental, and blood-milk barrier, and summarizes the existing evidence for the trans-barrier transport mechanism of ASMs and standard experimental models of biological barriers.

EXPERT OPINION

Ideal ASMs in the perinatal period should have the following characteristics: 1) Increased transport through the blood-brain barrier, and 2) Reduced transport of the placental and blood-milk barriers. Thus, only low-dose or almost no antiseizure medication could enter the fetus's body, which could decrease medication-induced fetal abnormalities. Based on the stimulated structure and molecular docking, we propose a development strategy for new ASMs targeting transporters of biological barriers to improve the perinatal treatment of female patients with epilepsy.

Morbidity and rehospitalization postpartum among women with epilepsy and their infants: A population-based study

OBJECTIVE

We compared the relative occurrence of selected pregnancy outcomes and postpartum rehospitalizations among women with and without epilepsy and their infants. Using linked vital-hospital discharge records of women with deliveries in Washington State 1987-2014, comparisons were made overall, by epilepsy type, and by time periods related to antiepileptic drug (AED) marketing changes.

METHODS

This population-based retrospective cohort study identified women with, and without epilepsy per diagnosis codes in the hospital discharge record from among all deliveries during 1987-2014 to examine maternal and infant outcomes, rehospitalization and mortality <2 years postpartum. Relative risks (RRs) and 95 % confidence intervals (CI) overall, and by epilepsy type were calculated using Poisson regression. We assessed the validity of epilepsy identification based on diagnosis codes by conducting a medical chart review for a sample of women.

RESULTS

Women with epilepsy had increased risks of preeclampsia (RR 1.23; 95 % CI 1.08-1.41) and gestational diabetes (RR 1.18; 95 % CI 1.02-1.36). Their infants had increased malformation (RR 1.23; 95 % C: 1.08-1.42) and small for gestational age (SGA, RR 1.39; 95 % CI 1.25-1.54) risks, and were nearly three times as likely to not be breastfed. Affected mothers (RR 5.25; 95 % CI 2.46-11.23) and their infants (RR 1.64, 95 % CI 1.41-1.89) required more ICU admissions during the delivery hospitalizations, and more postpartum rehospitalization, with greatest risk in the first six months. Maternal mortality < 2 years after delivery was increased (RR 7.11; 95 % CI 2.47-20.49). Increased risks were observed for all epilepsy subtypes for nearly all outcomes examined. Risks of preterm delivery and low birthweight increased over time (p <.05). Suggestive, but not statistically significant temporal decreases in risks of gestational diabetes and malformations and increased risk of preterm labor were noted. We observed high sensitivity of diagnosis codes for identifying pregnant women with epilepsy.

CONCLUSION

These population-based results emphasize the need for frequent postpartum monitoring of women with epilepsy. Increases in risks of low birthweight and preterm delivery over time are of concern. Possible temporal changes in other outcomes warrant further investigation.

Antiepileptic Drug Exposure in Infants of Breastfeeding Mothers With Epilepsy

Importance

There is limited information on infant drug exposure via breastfeeding by mothers who are receiving antiepileptic drug therapy.

Objective

To provide direct, objective information on antiepileptic drug exposure through breast milk.

Design, Setting, and Participants

This prospective cohort study was conducted between December 2012 to October 2016, with follow-up in children until 6 years of age at 20 sites across the United States. Data were collected via an observational multicenter investigation (Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs [MONEAD]) of outcomes in pregnant mothers with epilepsy and their children. Pregnant women with epilepsy who were aged 14 to 45 years, had pregnancies that had progressed to less than 20 weeks' gestational age, and had measured IQ scores of more than 70 points were enrolled and followed up through pregnancy and 9 postpartum months. Their infants were enrolled at birth. Data were analyzed from May 2014 to August 2019.

Exposures

Antiepileptic drug exposure in infants who were breastfed.

Main Outcomes and Measures

The percentage of infant-to-mother concentration of antiepileptic drugs. Antiepileptic drug concentrations were quantified from blood samples collected from infants and mothers at the same visit, 5 to 20 weeks after birth. Concentrations of antiepileptic drugs in infants at less than the lower limit of quantification were assessed as half of the lower limit. Additional measures collected were the total duration of all daily breastfeeding sessions and/or the volume of pumped breast milk ingested from a bottle.

Results

A total of 351 women (of 865 screened and 503 eligible individuals) were enrolled, along with their 345 infants (179 female children [51.9%]; median [range] age, 13 [5-20] weeks). Of the 345 infants, 222 (64.3%) were breastfed; the data collection yielded 164 matching infant-mother concentration pairs from 138 infants. Approximately 49% of all antiepileptic drug concentrations in nursing infants were less than the lower limit of quantification. The median percentage of infant-to-mother concentration for all 7 antiepileptic drugs and 1 metabolite (carbamazepine, carbamazepine-10,11-epoxide, levetiracetam, lamotrigine, oxcarbazepine, topiramate, valproate, and zonisamide) ranged from 0.3% (range, 0.2%-0.9%) to 44.2% (range, 35.2%-125.3%). In multiple linear regression models, maternal concentration was a significant factor associated with lamotrigine concentration in infants (Pearson correlation coefficient, 0.58; P < .001) but not levetiracetam concentration in infants.

Conclusions and Relevance

Overall, antiepileptic drug concentrations in blood samples of infants who were breastfed were substantially lower than maternal blood concentrations. Given the well-known benefits of breastfeeding and the prior studies demonstrating no ill effects when the mother was receiving antiepileptic drugs, these findings support the breastfeeding of infants by mothers with epilepsy who are taking antiepileptic drug therapy.

Which information on women's issues in epilepsy does a community pharmacist need to know? A Delphi consensus study

OBJECTIVE

The aim of this study was to develop and achieve consensus on a core list of important knowledge items that community pharmacists should know on women's issues in epilepsy.

METHODS

This was a consensual study using a modified Delphi technique. Knowledge items were collected from the literature and from nine key contacts who were interviewed on their views on what information community pharmacists should have on women's issues in epilepsy. More knowledge items were suggested by five researchers with interest in women's issues who were contacted to rate and comment on the knowledge items collected. Two iterative Delphi rounds were conducted among a panel of pharmacists (n=30) to achieve consensus on the knowledge items to be included in the core list. Ten panelists ranked the knowledge items by their importance using the Analytical Hierarchy Process (AHP).

RESULTS

Consensus was achieved to include 68 knowledge under 13 categories in the final core list. Items ranked by their importance were related to the following: teratogenicity (10.3%), effect of pregnancy on epilepsy (7.4%), preconception counseling (10.3%), bone health (5.9%), catamenial epilepsy (7.4%), menopause and hormonal replacement therapy (2.9%), contraception (14.7%), menstrual disorders and infertility (8.8%), eclampsia (2.9%), breastfeeding (4.4%), folic acid and vitamin K (5.9%), counseling on general issues (14.7%), and sexuality (4.4%).

CONCLUSION

Using consensual knowledge lists might promote congruence in educating and/or training community pharmacists on women's issues in epilepsy. Future studies are needed to investigate if such lists can improve health services provided to women with epilepsy (WWE).

Pregnancy Outcomes Following In Utero Exposure to Lamotrigine: A Systematic Review and Meta-Analysis

INTRODUCTION

Lamotrigine is used in pregnancy to control epilepsy and mood disorders. The reproductive safety of this widely used drug remains undefined and may represent a significant public health concern.

OBJECTIVE

We aimed to perform a systematic review and meta-analysis of existing knowledge related to malformation rates and maternal-neonatal outcomes after in utero exposure to monotherapy with lamotrigine.

METHODS

Relevant studies were identified through systematic searches conducted in MEDLINE (Ovid), Embase (Ovid), CENTRAL (Ovid), and Web of Science (Thomson Reuters) from database inception to July 2016; no language or date restrictions were applied. All publications of clinically relevant outcomes of pregnancies following in utero exposure to lamotrigine were included in this systematic review and meta-analysis.

RESULTS

A total of 21 studies describing immediate pregnancy outcomes and rates of congenital malformations fulfilled the inclusion criteria. Compared with disease-matched controls (n = 1412, total number of patients) and healthy controls (n = 774,571, total number of patients), in utero exposure to lamotrigine monotherapy was found to be associated with significantly decreased rates of inborn defects (odds ratio [OR] 1.15; 95% confidence interval [CI] 0.62-2.16 and OR 1.25; 95% CI 0.89-1.74, respectively). Rates of miscarriages, stillbirths, preterm deliveries, and small for gestational age (SGA) neonates were not found to have been increased after in-utero exposure to LTG compared to the general population. Similarly, in utero exposure to lamotrigine monotherapy was not found to be associated with increased rates of inborn defects compared with in utero exposure to carbamazepine, and lamotrigine was found to be statistically significantly less teratogenic than valproic acid (n = 12,958 and 10,748; OR 0.84; 95% CI 0.68-1.03 and OR 0.32; 95% CI 0.26-0.39, respectively).

CONCLUSION

No association was found between prenatal lamotrigine monotherapy and increased rates of birth defects and other explored variables related to adverse pregnancy outcomes.

Optimal Pain Management After Cesarean Delivery

Cesarean delivery rates are increasing worldwide, and effective postoperative pain management is a key priority of women undergoing cesarean delivery. Inadequate pain management in the acute postoperative period is associated with persistent pain, greater opioid use, delayed functional recovery, and increased postpartum depression. In addition to pain relief, optimal management of patients after cesarean delivery should address the goals of unrestricted maternal mobility, minimal maternal and neonatal side effects, rapid recovery to baseline functionality, and early discharge home. Multimodal analgesia should include neuraxial morphine in conjunction with nonopioid adjuncts, with additional oral or intravenous opioids reserved for severe breakthrough pain.

Issues for Women with Epilepsy

Epilepsy and antiepileptic drugs affect the menstrual cycle, aspects of contraception, reproductive health, pregnancy, and menopause through alteration of sex steroid hormone pathways. Sex steroid hormones often have an effect on seizure frequency and may alter the level of some antiepileptic drugs. Approximately one-third of women experience an increase in perimenstrual and/or periovulatory seizure frequency. Some women experience an increase in seizure frequency during pregnancy. Balancing maternal seizure control and the risk of congenital malformations associated with fetal antiepileptic drug exposure may be challenging. Some antiepileptic drugs are associated with cognitive and behavioral teratogenesis and should be avoided if possible during pregnancy.

Management of epilepsy during pregnancy: evidence-based strategies

Child-bearing years are often the most precarious management period in the life of a woman with epilepsy. This article reviews the results of many different studies with findings that enable the healthcare team to make confident decisions and recommendations during these critical periods. Preconceptional planning, effective contraception and folic acid supplementation are important fundamentals in preparation for pregnancy. There is growing evidence to avoid valproic acid use during the child-bearing years. Emerging data on congenital malformations and neurocognitive outcomes are available for some of the second-generation antiepileptic drugs and appear reassuring for lamotrigine and levetiracetam. Also reviewed are the benefits of postpartum drug tapers and favorable breastfeeding facts. Counseling the mother and her family on medication choices enables the healthcare team to implement informed decisions that are beneficial for the mother and child.

Breastfeeding in children of women taking antiepileptic drugs: cognitive outcomes at age 6 years

IMPORTANCE

Breastfeeding is known to have beneficial effects, but concern exists that breastfeeding during maternal antiepileptic drug (AED) therapy may be harmful. We previously noted no adverse effects of breastfeeding associated with AED use on IQ at age 3 years, but IQ at age 6 years is more predictive of school performance and adult abilities.

OBJECTIVES

To examine the effects of AED exposure via breastfeeding on cognitive functions at age 6 years.

DESIGN, SETTING, AND PARTICIPANTS

Prospective observational multicenter study of long-term neurodevelopmental effects of AED use. Pregnant women with epilepsy receiving monotherapy (ie, carbamazepine, lamotrigine, phenytoin, or valproate) were enrolled from October 14, 1999, through April 14, 2004, in the United States and the United Kingdom. At age 6 years, 181 children were assessed for whom we had both breastfeeding and IQ data. All mothers in this analysis continued taking the drug after delivery.

MAIN OUTCOMES AND MEASURES

Differential Ability Scales IQ was the primary outcome. Secondary measures included measures of verbal, nonverbal, memory, and executive functions. For our primary analysis, we used a linear regression model with IQ at age 6 years as the dependent variable, comparing children who breastfed with those who did not. Similar secondary analyses were performed for the other cognitive measures.

RESULTS

In total, 42.9% of children were breastfed a mean of 7.2 months. Breastfeeding rates and duration did not differ across drug groups. The IQ at age 6 years was related to drug group (P < .001 [adjusted IQ worse by 7-13 IQ points for valproate compared to other drugs]), drug dosage (regression coefficient, -0.1; 95% CI, -0.2 to 0.0; P = .01 [higher dosage worse]), maternal IQ (regression coefficient, 0.2; 95% CI, 0.0 to 0.4; P = .01 [higher child IQ with higher maternal IQ]), periconception folate use (adjusted IQ 6 [95% CI, 2-10] points higher for folate, P = .005), and breastfeeding (adjusted IQ 4 [95% CI, 0-8] points higher for breastfeeding, P = .045). For the other cognitive domains, only verbal abilities differed between the breastfed and nonbreastfed groups (adjusted verbal index 4 [95% CI, 0-7] points higher for breastfed children, P = .03).

CONCLUSIONS AND RELEVANCE

No adverse effects of AED exposure via breast milk were observed at age 6 years, consistent with another recent study at age 3 years. In our study, breastfed children exhibited higher IQ and enhanced verbal abilities. Additional studies are needed to fully delineate the effects of all AEDs.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00021866.

Breastfeeding and antiepileptic drugs

IMPORTANCE

Exposure to antiepileptic drugs during pregnancy is associated with adverse effects on psychomotor development.

OBJECTIVES

To determine whether signs of impaired development appear already during the first months of life in children exposed prenatally to antiepileptic drugs, and to explore potential adverse effects of antiepileptic drug exposure through breastfeeding.

DESIGN, SETTING, AND PARTICIPANTS

Mothers at 13 to 17 weeks of pregnancy were recruited in the population-based, prospective Norwegian Mother and Child Cohort Study from 1999 to 2009. The mothers reported on their child’s motor and social skills, language, and behavior using items from standardized screening tools at 6 months (n = 78 744), 18 months (n = 61 351), and 36 months (n = 44 147) of age. The mothers also provided detailed information on breastfeeding during the first year.

MAIN OUTCOMES AND MEASURES

The risk of adverse development in children according to maternal or paternal epilepsy was estimated as the odds ratio with corresponding 95% confidence interval, adjusted for maternal age, parity, education, smoking, breastfeeding, depression/anxiety, folate supplementation, and congenital malformation in the child.

RESULTS

At age 6 months, infants of mothers using antiepileptic drugs (n = 223) had a higher risk of impaired fine motor skills compared with the reference group (11.5% vs 4.8%, respectively; odds ratio = 2.1; 95% CI, 1.3–3.2). Use of multiple antiepileptic drugs compared with the reference group was associated with adverse outcome for both fine motor skills (25.0% vs 4.8%, respectively; odds ratio = 4.3; 95% CI, 2.0–9.1) and social skills (22.5% vs 10.2%, respectively; odds ratio = 2.6; 95% CI, 1.2–5.5). Continuous breastfeeding in children of women using antiepileptic drugs was associated with less impaired development at ages 6 and 18 months compared with those with no breastfeeding or breastfeeding for less than 6 months. At 36 months, prenatal antiepileptic drug exposure was associated with adverse development regardless of breastfeeding status during the first year. Children of women with epilepsy who did not use antiepileptic drugs and children of fathers with epilepsy had normal development at 6 months.

CONCLUSIONS AND RELEVANCE

Prenatal exposure to antiepileptic drugs was associated with impaired fine motor skills already at age 6 months, especially when the child was exposed to multiple drugs. There were no harmful effects of breastfeeding. Women with epilepsy should be encouraged to breastfeed their children irrespective of antiepileptic drug treatment.

Two nursing mothers treated with zonisamide: Should breast-feeding be avoided?

Zonisamide, an antiepileptic drug, is excreted into breast milk, but information regarding the safety of breast-feeding while using this drug is limited. We present the cases of two nursing mothers, taking 300 and 100 mg/day zonisamide. At 5 days after delivery, the milk concentrations and relative infant doses of the drug were 18.0 and 5.1 μg/mL, and 44 and 36%, respectively. In the first case, the mother fed colostrum and continued partial breast-feeding thus reducing the relative infant dose to 8%. The neonatal serum concentration of zonisamide declined to below the limit of detection at day 34 after birth. In the second case, the mother breast-fed partially until 2 weeks postpartum. No adverse effect was observed in the infants. These findings suggest that mothers taking zonisamide should not breast-feed exclusively, but may not have to avoid partial breast-feeding, with significant caution regarding adverse effects in infants.

Impact of early life exposure to antiepileptic drugs on neurobehavioral outcomes based on laboratory animal and clinical research

Epilepsy affects approximately 1% of children under the age of 15, making it a very common neurological disorder in the pediatric population (Russ et al., 2012). In addition, ~0.4-0.8% of all pregnant women have some form of epilepsy (Hauser et al., 1996a,b; Borthen et al., 2009; Krishnamurthy, 2012). Despite the potential deleterious effects of antiepileptic drugs (AEDs) on the developing brain, their use is still required for seizure control in pregnant women (Krishnamurthy, 2012), and they represent the standard approach for treating children with epilepsy (Chu-Shore and Thiele, 2010; Quach et al., 2010; Verrotti et al., 2011). Even when AEDs are effective, there are potential side effects, including cognitive and affective changes or altered sleep and appetite. The consequences of AED exposure in development have been studied extensively (Canger et al., 1999; Modi et al., 2011a,b; Oguni, 2011). Despite intensive study, there is still debate about the long-term consequences of early life AED exposure. Here, we consider the evidence to date that AED exposure, either prenatally or in early postnatal life, has significant adverse effects on the developing brain and incorporate studies of laboratory animals as well as those of patients. We also note the areas of research where greater clarity seems critical in order to make significant advances. A greater understanding of the impact of AEDs on somatic, cognitive and behavioral development has substantial value because it has the potential to inform clinical practice and guide studies aimed at understanding the genetic and molecular bases of comorbid pathologies associated with common treatment regimens. Understanding these effects has the potential to lead to AEDs with fewer side effects. Such advances would expand treatment options, diminish the risk associated with AED exposure in susceptible populations, and improve the quality of life and health outcomes of children with epilepsy and children born to women who took AEDs during pregnancy.

Managing epilepsy during pregnancy: assessing risk and optimizing care

OPINION STATEMENT

Epilepsy is the most common neurologic condition found in pregnancy. As such, all neurologists, internists, and obstetricians should know how to counsel women with epilepsy as they are considering pregnancy. While all of the usual recommendations for women of childbearing potential apply, including preconceptual and ongoing use of folic acid, calcium, and vitamin D, additional consideration must be given to the need for adjustment or change of anticonvulsant therapy. Monotherapy with the lowest dose of medication needed to control seizures should be prescribed prior to conception. Most anticonvulsants have a favorable profile when used in pregnancy; older anticonvulsants such as valproate and carbamazepine should be avoided, as they are associated with higher rates of fetal malformation, and in the case of valproate, with proven cognitive deficits in children exposed to this medication in utero. With use of any anticonvulsant medication, dosing throughout pregnancy will need to be adjusted to maintain an appropriate serum concentration. Dosing of anticonvulsants needs to be decreased after delivery to avoid medication-related toxicity, although sleep deprivation and hormonal fluctuation can increase the risk of seizures in postpartum women. With proper management, the majority of women with epilepsy can have uneventful pregnancies and healthy babies.

Effects of breastfeeding in children of women taking antiepileptic drugs

BACKGROUND

Breastfeeding is known to have beneficial effects, but there is concern that breastfeeding during antiepileptic drug (AED) therapy may be harmful to cognitive development. Animal and human studies have demonstrated that some AEDs can adversely affect the immature brain. However, no investigation has examined effects of breastfeeding during AED therapy on subsequent cognitive abilities in children.

METHODS

The Neurodevelopmental Effects of Antiepileptic Drugs Study is an ongoing prospective multicenter observational investigation of long-term effects of in utero AED exposure on cognition. Between 1999 and 2004, we enrolled pregnant women with epilepsy who were taking a single AED (carbamazepine, lamotrigine, phenytoin, or valproate). We recently reported on differential AED effects on age 3 year cognitive outcomes. In this report, we focus on the effects of breastfeeding during AED therapy on age 3 cognitive outcomes in 199 children.

RESULTS

A total of 42% of children were breastfed. IQs for breastfed children did not differ from nonbreastfed children for all AEDs combined and for each of the 4 individual AED groups. Mean adjusted IQ scores (95% confidence intervals) across all AEDs were breastfed = 99 (96-103) and nonbreastfed = 98 (95-101). Power was 95% to detect a half SD IQ effect in the combined AED analysis, but was inadequate within groups.

CONCLUSIONS

This preliminary analysis fails to demonstrate deleterious effects of breastfeeding during AED therapy on cognitive outcomes in children previously exposed in utero. However, caution is advised due to study limitations. Additional research is needed to confirm this observation and extend investigations to other AEDs and polytherapy.

Is breast-feeding of infants advisable for epileptic mothers taking antiepileptic drugs?

Epilepsy is a relatively common maternal complication affecting 0.3-0.5% of pregnant women. For most mothers with epilepsy, the use of antiepileptic drugs (AED) is unavoidable, even during pregnancy and lactation. Therefore, the fetus is indirectly exposed to AED via the placenta and breast milk. AED are also prescribed for female patients with other diseases, such as bipolar disorders. In clinical settings, physicians are frequently questioned whether or not women patients taking AED should breast-feed their offspring. Thus, it is necessary to establish an optimum AED regimen for women taking AED, in particular for those with epilepsy during pregnancy and lactation. In this article, we critically review the effects of AED on infants via breast milk and attempt to provide suggestions for clinicians regarding these effects during breast-feeding, based on the data of transplacental passage of AED, breast milk concentration/maternal serum concentration ratios, AED metabolism in infants and the effects of AED in breast milk on infants.