Malformation risks of antiepileptic drugs in pregnancy: a prospective study from the UK Epilepsy and Pregnancy Register

Preconception counselling for women with epilepsy to reduce adverse pregnancy outcome

BACKGROUND

The provision of preconception counselling to women with epilepsy (WWE) has become established as recommended practice and includes a review of drug treatment and the provision of information and advice on both seizure and treatment-related risks to both mother and child. In this review we assess the evidence regarding the effectiveness of preconception counselling for WWE.

OBJECTIVES

To determine the effectiveness of preconception counselling for WWE, measured by a reduction in adverse pregnancy outcome in both mother and child; increased knowledge of preconception issues in WWE and increasing intention to plan pregnancy.

SEARCH STRATEGY

We searched the Epilepsy Group's Specialized Register (30/01/2008), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 4), and electronic databases: MEDLINE (OVID) (1950-February 2008); SCOPUS (1966-March 2008); CINAHL (1982-March 2008); PsyclNFO (1806-March 2008); ASSIA (1987-March 2008).

SELECTION CRITERIA

Randomised control trials; including cluster and quasi-randomised trials, prospective cohorts, controlled before and after studies, and interrupted time series that compared the outcomes in mothers with epilepsy and infants of mothers with epilepsy who received preconception counselling, to the outcomes of mothers with epilepsy and their infants who received standard care or no intervention.

DATA COLLECTION AND ANALYSIS

The methodological quality of potentially relevant studies were assessed to determine appropriate inclusion. Where necessary, study authors were contacted for additional information. No studies met the review inclusion criteria.

MAIN RESULTS

The search strategy identified 11 studies for consideration of inclusion. However, none met the required criteria for inclusion.

AUTHORS' CONCLUSIONS

There is no evidence to inform the content, methods of delivery or effectiveness of preconception counselling to improve pregnancy outcomes for WWE and their offspring. The value of counselling delivered to WWE prior to conception, with the intention of reducing the risks of adverse outcome in mother and child, requires evaluation in well-designed studies, appropriately powered to detect changes in both maternal and infant outcome.

Pregnancy outcome after in utero exposure to valproate : evidence of dose relationship in teratogenic effect

BACKGROUND

Valproate is a first-line antiepileptic agent and is also used in the treatment of bipolar disorder and migraine. It is a known human teratogen. The objective of the study was to evaluate the teratogenic risk of valproate.

METHODS

All callers who contacted the Israeli Teratology Information Service (TIS) between 1994 and 2004 for information about gestational exposure to valproate were enrolled in the study. After the expected date of delivery, these women were followed up by telephone interview about their pregnancy outcome using a structured questionnaire. Data obtained from women who contacted the TIS about valproate exposure during pregnancy were then compared with data obtained from callers who were counselled for nonteratogenic exposures over the same timeframe. The main outcome measure was the rate of major congenital anomalies.

RESULTS

The outcomes of 154 valproate-exposed pregnancies (96.1% at least in the first trimester) were compared with those of 1315 pregnancies of women in the TIS database who were counselled for nonteratogenic exposures. The rate of major anomalies (some multiple) in the valproate group exposed in the first trimester was higher compared with controls after exclusion of genetic or cytogenetic anomalies (8 of 120 [6.7%] vs 31 of 1236 [2.5%], p = 0.018, relative risk [RR] = 2.66, 95% CI 1.25, 5.65). There were no cases of neural tube defect in the valproate-exposed group. Five of the eight major anomalies in the valproate group were cardiovascular, two of eight were mentally retarded, two of five male infants with major anomalies had hypospadias and three of eight were suspected of having fetal valproate syndrome. A daily dose > or =1000 mg was associated with the highest teratogenic risk (7 of 32 [21.9%] vs 31 of 1236 [2.5%], RR = 8.72, 95% CI 4.16, 18.30). In the subgroup exposed to polytherapy there was a 4-fold increase in the rate of major anomalies compared with controls. All major anomalies were in the group treated for epilepsy.

CONCLUSION

When valproate treatment cannot be avoided in the first trimester of pregnancy, the lowest effective dose should be prescribed, preferably as monotherapy, to minimize its teratogenic risk.

Perinatal depression: treatment options and dilemmas

The treatment of depression during pregnancy and the postpartum period raises unique concerns about safety for the developing fetus and the infant. An increasing number of studies suggest adverse effects from untreated stress, anxiety and depression as well as adverse effects from antidepressant and other psychotropic medications. Even when studies suggest a lack of short-term adverse effects with some medications, the paucity of systematic longitudinal follow-up studies investigating the development of children exposed to medications during pregnancy and breastfeeding causes apprehension. This review's objective is to highlight what is currently known about the negative effects of untreated disease and exposure to psychotropic medication, the treatment dilemmas confronting women with perinatal depression and issues that future studies should address so that a woman with perinatal depression can make an optimally informed decision.

Effect of anti-epileptic drugs in pregnancy and teratogenesis

Epilepsy raises special concern in women during pregnancy. Antiepileptic drugs are known to induce major and minor malformations in the foetus. Aim of the study was to find an association between maternal serum alpha fetoprotein levels, foetal abnormalities and antiepileptic drugs mediated teratogenicity. Maternal serum alpha feto protein levels, kidney and liver function tests in age matched normal pregnant women and seizure free epileptic pregnant women during 12-14 weeks of gestation were estimated. Cases were subjected to ultrasonography at 11(th)-14(th) week of pregnancy and again at 20(th) week of pregnancy. maternal serum alfa feto protein was assayed by a specific Electro Chemiluminescence Immuno Assay test. There was no significant difference in kidney and liver function tests in cases as compared to controls. There were elevated levels of alpha feto protein in cases as compared to controls but this was not statistically significant. No anomalies were detected in ultrasound reports. Most women had normal full term delivery with healthy children but of low birth weight. No correlation was seen between maternal serum alfa feto protein levels and antiepileptic drug leading to teratogenesis.

Motor and mental development of infants exposed to antiepileptic drugs in utero

We prospectively evaluated the mental (MeDQ) and motor (MoDQ) developmental quotients of 395 (67.5% of the eligible) infants of mothers with epilepsy (IME) (mean age: 15 months) enrolled in the Kerala Registry of Epilepsy and Pregnancy between 1998 and 2004. The same developmental pediatricians, blinded to antiepileptic drug (AED) exposure, evaluated the children using the Indian adaptation of the Bayley Scale of Infant Development: Their mean MeDQ was 89.1+/-29.9 and mean MoDQ was 90.7+/-26.9. The MeDQ and MoDQ were impaired (<84) for 150 (37.6%) and 133 (33.5%) IME, respectively. Maternal age, type of epilepsy, seizure frequency, or use of folic acid did not correlate with the mean MeDQ or MoDQ. Maternal education was significantly correlated with the MoDQ, but not with the MeDQ, of the infants. Infants not exposed to AEDs (n=32) had a higher MeDQ (mean: 92.3, 95% CI: 81.4-103.2) and MoDQ (mean 94.7; 95% CI 84.9-104.5) than those exposed to AEDs (MeDQ--mean: 88.6, 95% CI: 85.5-91.6; MoDQ--mean: 90.0, 95% CI: 87.3-92.8). Those exposed to polytherapy had significantly lower developmental quotients than those exposed to monotherapy. Cumulative AED scores during pregnancy had an inverse relationship with developmental quotients. On multiple regression analysis, polytherapy was a stronger predictor of lower developmental quotients than dosage. Compared with carbamazepine monotherapy, valproate monotherapy was associated with significantly lower MeDQ and MoDQ in IME (93.1 and 95 vs 86.9 and 86.1), but the differences between other AEDs were not significant for IME exposed to valproate monotherapy. A limitation of the study is that the influence of maternal intelligence on developmental quotients was not evaluated.

Lamotrigine in breast milk and nursing infants: determination of exposure

OBJECTIVE

Although lamotrigine use during pregnancy has substantially increased over the past decade secondary to accumulated reproductive safety data, systematic data on lamotrigine during breastfeeding remains sparse. We sought to characterize the determinants of lamotrigine concentrations in breast milk and nursing-infant plasma.

PATIENTS AND METHODS

Women who enrolled in a prospective investigation of perinatal medication pharmacokinetics, were treated with lamotrigine, and chose to continue lamotrigine while breastfeeding were included in the analysis. Breast milk samples were collected via breast pump from foremilk to hindmilk from a single breast to determine the excretion gradient and serial samples over 24 hours to determine the time course of excretion. Paired maternal/infant plasma samples were also collected. Lamotrigine concentrations in all of the samples were determined by using high-performance liquid chromatography with ultraviolet detection. Statistical analyses of breast milk and infant plasma concentrations and their determinants were conducted.

RESULTS

Thirty women and their nursing infants participated in the study, providing a total of 210 breast milk samples. The mean milk/plasma ratio was 41.3%. There was a nonsignificant trend for higher lamotrigine concentrations in breast milk 4 hours after the maternal dose. Infant plasma concentrations were 18.3% of maternal plasma concentrations. The theoretical infant lamotrigine dose was 0.51 mg/kg per day, and the relative infant lamotrigine dose was 9.2%. Mild thrombocytosis was present in 7 of 8 infants at the time of serum sampling. No other adverse events were observed or reported in the breastfed infants.

CONCLUSIONS

Consistent with previous investigations of medications in breast milk, the lamotrigine milk/plasma ratio is highly variable. The rate of lamotrigine excretion into human breast milk is similar to that observed with other antiepileptic drugs. These data expand the extant literature on lamotrigine in breastfeeding and demonstrate relatively comparable nursing-infant exposure to lamotrigine compared with other antiepileptic drugs.

Pregnancy outcomes in women with epilepsy: a systematic review and meta-analysis of published pregnancy registries and cohorts

PURPOSE

To conduct a systematic review and meta-analysis to quantify the incidence of congenital malformations (CMs) and other pregnancy outcomes as a function of in utero anti-epileptic drug (AED) exposure.

METHODS

We performed a systematic literature review to identify all published registries and cohort studies of births from pregnant women with epilepsy (WWE) that reported incidence of CMs. Overall incidences were calculated using a random effects model.

RESULTS

The review included 59 studies that met inclusion/exclusion criteria, involving 65,533 pregnancies in WWE and 1,817,024 in healthy women. The calculated incidence of births with CM in WWE [7.08%; 95% CIs 5.62, 8.54] was higher than healthy women [2.28%; CIs 1.46, 3.10]. Incidence was highest for AED polytherapy [16.78%; CIs 0.51, 33.05]. The AED with the highest CM incidence was valproate, which was 10.73% [CIs 8.16, 13.29] for valproate monotherapy.

CONCLUSIONS

Results of this systematic literature review suggest that the overall incidence of CMs in children born of WWE is approximately threefold that of healthy women. The risk is elevated for all AED monotherapy and further elevated for AED polytherapy compared to women without epilepsy. The risk was significantly higher for children exposed to valproate monotherapy and to polytherapy of 2 or more drugs when the polytherapy combination included phenobarital, phenytoin, or valproate. Further research is needed to delineate the specific risk for each individual AED and to determine underlying mechanisms including genetic risk factors.

Valproate teratogenicity and epilepsy syndrome

Maternal valproate (VPA) use is associated with a significant risk for congenital malformations in the exposed fetus. Since VPA is commonly used in epilepsy syndromes with a presumed genetic cause (idiopathic epilepsies), it is possible that maternal genetic background contributes to this outcome. We reviewed responses to telephone questionnaires and medical records, when available, of enrollees in the North American Antiepileptic Drug Pregnancy Registry, classifying reason for treatment as idiopathic generalized epilepsy (IGE), partial epilepsy (PE), nonclassifiable epilepsy (NCE), or not epilepsy (NE). Of 284 VPA-exposed pregnancies, 30 (11.0%) were associated with malformations: IGE = 15/126 (12%), PE = 4/28 (14%), NCE = 9/105 (9%), NE = 2/25 (8%) (p > 0.7 for all comparisons). There was a trend toward increased malformation risk with higher VPA doses (p = 0.07). VPA, and not the underlying genetic syndrome, seems to be associated with the elevated risk for malformations in the drug-exposed fetus.

Neurodevelopmental delay in children exposed to antiepileptic drugs in utero: a critical review directed at structural study-bias

INTRODUCTION

The general issue whether in utero exposure to antiepileptic drugs (AEDs) causes congenital malformations (teratogenicity) was raised as early as 1968. The 'congenital hydantoin syndrome' after intrauterine exposure to phenytoin (PHT) was first described in 1975. In 1984, DiLiberti proposed the label 'Fetal Valproate Syndrome' (FVS) for children with a cluster of minor congenital anomalies in the form of dysmorphic facial appearances with or without major abnormalities after intra-uterine exposure to valproate (VPA). Later, also the presence of central nervous system (CNS) dysfunction became part of the description. The question whether developmental delay, educational impairment, or behavioural disorders are also a characteristic of intrauterine exposure to AEDs and especially VPA, is of major importance to many women with epilepsy, parents and physicians involved.

METHODS

Literature was searched using MEDLINE and other relevant databases: 56 studies were identified and interpreted.

RESULTS

The identified studies do not allow definite conclusions. The possibility of neurodevelopmental delay, behavioural disorders, or learning disabilities as an outcome of in utero exposure to AEDs and especially VPA, needs to be considered seriously. The literature however does not provide evidence for a valid risk estimate. Moreover the evidence found for a specific increased risk for VPA could be structurally biased.

DISCUSSION

The major problem in this field is the methodology and in particular the existence of important confounding factors that complicate any attempt to correlate intra-uterine exposure to AEDs with neurodevelopmental delay. We propose a number of guidelines for studies on behavioural teratogenicity.

Data resources for investigating drug exposure during pregnancy and associated outcomes: the General Practice Research Database (GPRD) as an alternative to pregnancy registries

Pregnancy registries are the most commonly used data resource for the post-marketing surveillance of drug teratogenicity. However, the limited sample size and potential selection bias in these registries has led us to investigate the potential of the UK General Practice Research Database (GPRD) as an alternative data source for monitoring drug safety during pregnancy. In addition, a literature review identified further observational data sources that monitor pregnancy outcomes for future evaluation. Initial feasibility studies focused on the ability of the GPRD to capture pregnancy outcomes for a range of drug class exposures, all of which are currently under investigation in pregnancy registries, during pregnancy. The comparator pregnancy registries were identified via a MEDLINE search, whilst eligible pregnancies, in which women received one or more prescriptions for the drug of interest during pregnancy, were identified in the GPRD using the mother-baby link. The number of pregnancy outcomes following exposure to medication for a range of conditions with varying prevalence, including depression, migraine, epilepsy, herpes simplex and HIV, captured by the two data sources were compared. For depression, a relatively prevalent condition, the GPRD recorded the same number of mean annual intrauterine exposures to fluoxetine as the pregnancy registry (118 exposures/year). Ascertainment of intrauterine exposure to drug treatments for less prevalent conditions was found to be higher for the pregnancy registries than the GPRD; for the older antiepileptic drugs (valproate and carbamazepine), the pregnancy registry recorded between four and five times as many mean annual exposures as the GPRD. Virtually no antiretroviral exposures (three) were identified during the time period of interest on the GPRD, compared with 3946 in the Antiretroviral Pregnancy Registry. Data from the GPRD meet established criteria for evaluating outcomes of pregnancy. For prevalent conditions, it has the potential to replace or work alongside standard pregnancy registries and the alternative data sources identified. Further studies are now needed to assess its ability to replicate known teratogenic associations.

Lamotrigine in bipolar disorder: efficacy during pregnancy

OBJECTIVE

Clinical management of bipolar disorder (BPD) patients during pregnancy is a major challenge. The high risk of bipolar depression during pregnancy encourages consideration of lamotrigine (LTG). We therefore compared recurrence risks among pregnant women with BPD treated with LTG to those discontinuing mood stabilizer therapies.

METHODS

We compared risks and weeks to new DSM-IV illness-episodes among 26 initially clinically stable pregnant women diagnosed with DSM-IV BPD who continued LTG treatment to those discontinuing all mood stabilizer treatment during pregnancy.

RESULTS

The risk of new illness-episodes with LTG was 30% versus 100% after discontinuing mood stabilizers, and survival-computed time-to-25%-recurrence was 28.0 versus 2.0 weeks (chi(2 )=17.3, p < 0.0001; hazard ratio = 12.1; 95% confidence interval = 1.6-91.7).

CONCLUSIONS

Discontinuing mood stabilizer treatment presents high risks of illness-recurrence among pregnant women diagnosed with BPD. LTG may afford protective effects in pregnancy, and its reported fetal safety compares favorably to other agents used to manage BPD.

Cardiac malformations are increased in infants of mothers with epilepsy

We aimed to ascertain the prevalence of cardiac malformation (CM) and its association with antenatal exposure to an antiepileptic drug (AED) in infants of mothers with epilepsy (IMEs). Women with epilepsy (WWE) are enrolled in Kerala Registry of Epilepsy and Pregnancy (KREP) in the prepregnancy or early pregnancy period and are followed up with a standard protocol until the IMEs are 6 years old. At 3 months postpartum, a cardiologist, blinded to the AED exposure, carried out a clinical examination and echocardiography on all live-born babies. Patent foramen ovale (PFO) and interatrial septal defects of < 5 mm in size were excluded from CM. Details of maternal epilepsy, folate usage, AED exposure in the first trimester, and newborn characteristics were abstracted from the records of the KREP. We examined 462 babies. Maternal epilepsy was generalized in 201 (43.50%) or localization related in 241 (52.2%). The AED exposure was monotherapy in 262 (56.7%)--carbamazepine (112), valproate (71), phenobarbitone (43), phenytoin (31), and clonazepam (2)--and polytherapy in 126 (27.3%). Seventy-four infants (16.01%) had no AED exposure. There were 36 infants with CM (7.8%; 95% confidence interval: 5.5-10.6). CMs included atrial septal defect (26; 72.2%), tetrology of Fallot (3; 8.3%), patent ductus arteriosus and pulmonic stenosis (2 each; 5.6%), and ventricular septal defect, tricuspid regurgitation, transposition of great arteries (1 each; 2.8%). CMs were significantly more for IMEs with premature birth (p < .003). There was no association between CM and maternal age, epilepsy syndrome, seizure frequency during pregnancy, and folate use. CMs were more frequent with polytherapy (13; 10.3%) compared to monotherapy (17; 6.5%). Those with valproate exposure had a trend (not statistically significant) toward higher frequency of CM compared to IMEs on other AEDs as monotherapy.

Ethical and regulatory issues related to pregnancy registries and their outcomes

Pregnancy registries should be devised so that the interests of science, society, and the individual are all considered. For example, there may be ethical issues that relate to how women are chosen to participate in the registry and how informed consent is obtained. In most cases, consent is required for both the mother and the infant. Some institutional review boards will require that consent be obtained by someone other than the woman's physician. Once data are obtained, there may be an issue as to when results should be released. Options are to release data when there is the first indication of a concerning finding, thereby potentially preventing exposure in the largest number of women, versus waiting until the finding is absolutely confirmed. In a related issue, there are questions of when and how regulatory agencies should change labeling based on findings.

Modern management of epilepsy: a practical approach

The epilepsies are among the most common serious brain disorders, can occur at all ages, and are characterized by a variety of presentations and causes. Diagnosis of epilepsy remains clinical, and neurophysiological investigations support the diagnosis of the syndrome. Brain imaging is able to identify many of the structural causes of the epilepsies. Current antiepileptic drugs (AEDs) block seizures without influencing the underlying tendency to generate seizures, and are effective in 60-70% of individuals. Several modern drugs are as efficacious as the older medications, but have important advantages including the absence of adverse drug interactions and hypersensitivity reactions. Epilepsy is associated with an increased prevalence of mental health disorders including anxiety, depression, and suicidal thoughts. An understanding of the psychiatric correlates of epilepsy is important to the adequate management of people with epilepsy. Anticipation of common errors in the diagnosis and management of epilepsy is important. Frequent early diagnostic errors include nonepileptic psychogenic seizures, syncope with myoclonus, restless legs syndrome, and REM behavioral disorders, the last mostly in elderly men. Overtreatment with too rapid titration and too high doses or too many AEDs should be avoided. For people with refractory focal epilepsy, vagus nerve stimulation offers palliative treatment with possible mood improvement and neurosurgical resection offers the possibility of a life-changing cure. Potential advances in the management of epilepsy are briefly discussed. This short review summarizes the authors' how-to-do approach to the modern management of people with epilepsy.

Pregnancy, epilepsy, and anticonvulsants

The majority of epileptic disorders are not self-limiting over time, and therefore require a long-lasting and often even lifelong antiepileptic drug (AED) treatment, in Wi/omen with epilepsy, the influence of their disease on the possibility and course of pregnancies, as well as the potential impact of the AED treatment on mother and child, are crucial questions.

This review addresses the clinically relevant knovledge concerning the impact of the disease itself and the AED treatment on fertility, pregnancy, delivery, the postpartum period, and teratogenicity. Some of the new AEDs appear to have a favorable profile due to a lack of clinically relevant interactions and promising teratogenic profiles. However, the finding of decreases in lamotrigine serum concentrations during hormonal contraception and pregnancy is an instructive example, shovt/ing that ongoing studies are urgently needed to further investigate stillunanswered questions. Several prospective multinational surveys are currently being performed, and should add essential information in this context.

Fetal anticonvulsant syndromes and polymorphisms in MTHFR, MTR, and MTRR

The malformations found in fetal anticonvulsant syndromes (FACS) are associated with folic acid deficiency and methylene-tetrahydrofolate reductase (MTHFR) polymorphisms in the general population. To investigate a possible association between FACS and MTHFR genotype, we recruited 200 mothers who had taken anti-epileptic drugs in pregnancy, and delivered at Aberdeen Maternity Hospital over a 26-year period. Clinical findings in the mothers and their 337 children were documented. A clinical algorithm was devised to diagnose FACS objectively. Case-parent triads were genotyped for polymorphisms in MTHFR, serine hydroxymethyl transferase (SHMT1), methionine synthase (MTR), and methionine synthase reductase (MTRR), and analyzed by log-linear regression. No effect of the child's genotype on congenital malformation, neurodevelopmental disorder or FACS was detected using this method. The risk of having a child with congenital malformation or FACS was three to four times higher for mothers who were MTHFR 677TT homozygotes compared with MTHFR 677CC homozygotes. MTR 2756A > G and MTRR 66A > G genotype frequencies in children with FACS and neurodevelopmental disorder were different from those in healthy blood donor controls.

[Treatment of epilepsy in adults. Options and strategies]

Currently, epilepsy can be treated with antiepileptic drugs and, in patients with focal and/or secondarily generalized seizures (focal epilepsy), by means of surgery and vagus nerve stimulation. In the choice of monotherapy possible negative drug related effects on cognitive, endocrine, and psychic symptoms must be considered. Newly developed antiepileptic drugs help to establish an individualized strategy, especially in antiepileptic drug monotherapy. Additionally these antiepileptic drugs have proven to be effective and well tolerated when combined with other antiepileptic drugs. Surgery of focal epilepsy offers the chance of complete cure. Vagus nerve stimulation is a nonmedical treatment option used in addition to antiepileptic drugs in patients with focal epilepsy. Tolerability and safety data should be considered to establish a long-term medical treatment tolerated and accepted by the patient.

Pregnancy, epilepsy, and anticonvulsants

The majority of epileptic disorders are not self-limiting over time, and therefore require a long-lasting and often even lifelong antiepileptic drug (AED) treatment. In women with epilepsy the influence of their disease on the possibility and course of pregnancies, as well as the potential impact of the AED treatment on mother and child, are crucial questions. This review addresses the clinically relevant knowledge concerning the impact of the disease itself and the AED treatment on fertility pregnancy, delivery, the postpartum period, and teratogenicity. Some of the new AEDs appear to have a favorable profile due to a lack of clinically relevant interactions and promising teratogenic profiles. However, the finding of decreases in lamotrigine serum concentrations during hormonal contraception and pregnancy is an instructive example, showing that ongoing studies are urgently needed to further investigate still-unanswered questions. Several prospective multinational surveys are currently being performed, and should add essential information

Lamotrigine in pregnancy: clearance, therapeutic drug monitoring, and seizure frequency

OBJECTIVE

To characterize the magnitude and course of alterations in total and free lamotrigine (LTG) clearance (Cl) during pregnancy and the postpartum period, to assess the impact of therapeutic drug monitoring (TDM) on seizure frequency, to determine the ratio to individual target LTG concentration that is associated with increased seizure risk, and to evaluate maternal postpartum toxicity.

METHODS

A cohort of women were enrolled before conception or during pregnancy in this prospective, observational study. Visits occurred every 1 to 3 months with review of seizure and medication diaries, examination, and blood sampling. Total and free LTG Cls were calculated. Individualized target concentrations were used for TDM. The ratio to target concentration (RTC) was compared between patients with and without increased seizures. A receiver operating characteristic curve determined the threshold RTC that best predicts increased seizure frequency.

RESULTS

Analysis of 305 samples in 53 pregnancies demonstrated increased total and free LTG Cl in all trimesters above nonpregnant baseline (p < 0.001), with peak increases of 94% and 89% in the third trimester. Free LTG Cl was higher in white compared with black women (p < 0.05). Increased seizure frequency (n = 36 women with epilepsy) in the second trimester was associated with a lower RTC (p < 0.001), and RTC < 0.65 was a significant predictor of seizure worsening. An empiric postpartum taper reduced the likelihood of maternal LTG toxicity (p < 0.05) (n = 27). Newborn outcomes were similar to the general population (n = 52).

CONCLUSIONS

These novel data contribute to a rational treatment plan and dosing paradigm for lamotrigine use during pregnancy, parturition, and the postpartum period.

Antiepileptic drug exposure and major congenital malformations: the role of pregnancy registries

The use of antiepileptic drugs (AEDs) in pregnancy is associated with an increased risk of fetal malformations. Although it is known that AEDs may differ with respect to the type of malformations they can induce, earlier studies have generally lacked the power to demonstrate differences between AEDs in their overall teratogenic potential. Furthermore, there is an urgent need to assess the clinical teratogenic potential of the newer-generation AEDs. Epilepsy and pregnancy registries have been established to provide such information, which is essential for the rational management of women with epilepsy with childbearing potential. The registries also provide opportunities for additional studies of seizures observed during pregnancy and labor and, with the enrolled woman's consent, for separate studies on cognitive outcomes and pharmacogenetics. Although most are prospective, the existing registries vary somewhat in design, which needs to be considered when their results are compared. Some registries are driven by pharmaceutical companies (often compelled by national or international drug licensing agencies) and provide data on pregnancy outcome related to the sponsor's own product. Others are organized by independent research groups and are potentially more useful in that they publish comparative data. This review provides a critical discussion and comparison of important methodological aspects of AED and pregnancy registries along with a summary of results published so far.

Informing patients of the teratogenic potential of mood stabilizing drugs: a case note review of the practice of psychiatrists

Lithium, carbamazepine and valproate are established human teratogens. Women of childbearing potential who are prescribed these drugs should be informed of their teratogenic potential and advised of the need for adequate contraception and the protective role of folate. We reviewed the clinical records of all women of childbearing age in long-term contact with one specialist mental health Trust providing services for a total population of 750,000. One hundred and thirty eight (16%) of 837 women of childbearing age were prescribed one or more of these drugs. There was documented evidence that 29 (21%) of these women had been informed about teratogenicity and that 33 (24%) had been advised about contraception. Fourteen women (10%) had a confirmed pregnancy while taking lithium, carbamazepine or valproate; eight had a complication of pregnancy. If prescribing practice in this large mental health Trust were typical of the UK, between 7000 and 11 000 women of childbearing potential would be prescribed lithium, carbamazepine or valproate by psychiatrists without documented discussion of the risks.

Epilepsy in pregnancy

This article explores the therapeutic problems that arise when a patient with epilepsy on treatment becomes pregnant and needs both effective seizure control and attention to the safety of her fetus

The Australian antiepileptic drug in pregnancy register: Aspects of data collection and analysis

Internal comparisons using the data of the Australian Register of Antiepileptic Drugs in Pregnancy as of November 2005, and comparisons with Australian population data, were carried out. It was found that (i) except for under-representation of mothers of Asian origin, the demography of the register population was reasonably representative of the Australian situation; (ii) except for more pregnancies terminated for foetal malformation, malformation rates were similar in retrospectively and non-retrospectively enrolled pregnancies; (iii) some 21% of foetal malformations would have been excluded by not including malformations first recognised after the neonatal period; and (iv) in practice, the comparator against which malformation rates were expressed made little difference to the rates found. It is desirable to have available such analyses of pregnancy register data before comparing the findings of different registers.

Emerging drugs for epilepsy

Epilepsy affects < or = 1% of the world's population. Antiepileptic drugs (AEDs) are the mainstay of treatment, although more than a third of patients are not rendered seizure free with existing medications. Uncontrolled epilepsy is associated with increased mortality and physical injuries, and a range of psychosocial morbidities, posing a substantial economic burden on individuals and society. Limitations of the present AEDs include suboptimal efficacy and their association with a host of adverse reactions. Continued efforts are being made in drug development to overcome these shortcomings employing a range of strategies, including modification of the structure of existing drugs, targeting novel molecular substrates and non-mechanism-based drug screening of compounds in traditional and newer animal models. This article reviews the need for new treatments and discusses some of the emerging compounds that have entered clinical development. The ultimate goal is to develop novel agents that can prevent the occurrence of seizures and the progression of epilepsy in at risk individuals.

Early intervention for the ocular and neurodevelopmental sequelae of Fetal Valproate Syndrome

The established teratogenicity of antiepileptic drugs raises important issues in women of child-bearing age. While the association between neural tube defects and antiepileptic drugs is well recognised, other congenital malformations are known to occur. We report two siblings with characteristic craniofacial features of Fetal Valproate Syndrome who also had associated ocular and neurodevelopmental problems which would benefit from early recognition and intervention.

Antiepileptic medication during pregnancy: does fetal genotype affect outcome?

Congenital abnormalities and impaired development in childhood are attributable to fetal exposure to antiepileptic drugs (AEDs). Pregnancy registries set up to obtain information about the potential risks of fetal exposure to AEDs, in particular major congenital malformations (MCMs), suggest that valproate exposure increases the frequency of congenital malformations more than other AEDs. Furthermore, follow-up studies have drawn attention to cognitive impairments in later childhood after prenatal exposure to valproate. Fetal exposure to AEDs may be influenced by drug transporting proteins in the placenta, including P-glycoprotein (P-gp), multidrug resistance protein (MRP) 1, and breast cancer resistance protein (BCRP). Their location in the syncytiotrophoblast plasma membrane, at the interface of the maternal and fetal circulations, allows these transport proteins to efflux xenobiotics back to the mother and offers the fetus protection from medications taken during pregnancy. Genetic variations in the expression and activity of these transport proteins may influence fetal exposure to AEDs and thus the risk of teratogenicity. Identification of a hierarchy of haplotypes ranging from susceptible to protective of congenital abnormalities could assist genetic counseling, in assessing fetal risks from exposure to AEDs.

The role of lamotrigine in the management of bipolar disorder

Lamotrigine has emerged with a distinct place in the pharmacological treatment of bipolar disorder, with the potential to treat and prevent bipolar depression, which is the dominant and arguably most disabling and under-treated phase of the illness. This review examines the published clinical trials of lamotrigine in bipolar treatment. While the data supports its tolerability and safety, the strongest evidence for its efficacy lies in the prevention of bipolar depression, with weaker evidence for the treatment of acute bipolar depression, refractory unipolar and bipolar depression, and rapid cycling bipolar disorder. The total number of published well designed trials is small, even the maintenance evidence is derived from two studies. However, this relative inadequacy compares favorably with the alternative treatment options for bipolar depression, which are marked by poor efficacy or risk of polarity switch. The designation of lamotrigine as first-line treatment for bipolar depression prophylaxis should be done in cognizance of this context, and it would seem prudent to await greater evidence of efficacy before designating lamotrigine as first-line treatment for other bipolar indications. Further randomized controlled trials are required to consolidate the available findings and to explore the boundaries of lamotrigine's efficacy, which may encompass the soft spectral disorders.

Costs of NHS maternity care for women with multiple pregnancy compared with high-risk and low-risk singleton pregnancy

OBJECTIVE

To compare antenatal and obstetric costs for multiple pregnancy versus singleton pregnancy risk groups and to identify factors driving cost differentials.

DESIGN

Observational study over 15 months (2001-02).

SETTING

Four district hospitals in southeast England.

POPULATION

Consecutive women with multiple pregnancy and singleton women with risk factors for fetal congenital heart disease (CHD) (pregestational diabetes, epilepsy, or family history of CHD) or Down syndrome, and a sample of low-risk singleton women.

METHODS

Clinical care was audited from the second trimester anomaly scan until postnatal discharge, and the resource items were costed. Multiple regression analysis determined predictors of costs.

MAIN OUTCOME MEASURES

NHS mean costs of antenatal and obstetric care for different types of pregnancy.

RESULTS

A total of 959 pregnancies were studied. Three percent of 243 women with multiple pregnancy reached 40 weeks of gestation compared with 54-55% of 163 low-risk and 322 Down syndrome risk women and 36% of 231 cardiac risk women. Antenatal costs for cardiac risk (1,153 pounds sterling) and multiple pregnancy (1,048 pounds sterling) were nearly double the costs for other two groups (P < 0.001). As 63% of multiple births were delivered by caesarean section, the obstetric cost for multiple pregnancy (3,393 pounds sterling) was 1,000 pounds sterling greater overall. Pregestational diabetes was the most influential factor driving singleton costs, resulting in similar total costs for multiple pregnancy women (4,442 pounds sterling) and for women with diabetes (4,877 pounds sterling).

CONCLUSIONS

Our analyses confirm that multiple pregnancies are substantially more costly than most singleton pregnancies. Identifying women with diabetes as equally costly is pertinent because of the findings of the Confidential Enquiry into Maternal and Child Health that standards of maternal care for diabetics often are inadequate.

Pharmacotherapy of epilepsy: new armamentarium, new issues

Since 1990 there have been over ten antiepileptic drugs (AEDs) approved for the therapy of epilepsy. These agents have a new spectrum of efficacy and novel adverse effects, some totally unexpected. They also represent an enormous escalation of costs. Few have been subjected to head-to-head comparisons in monotherapy against established AEDs. The aim of therapy is to eliminate rather than to reduce seizure manifestations. Many traditional agents have been phased out due to poor tolerability. New epilepsy syndromes and genetic contributions to epilepsy have been refined. Special considerations apply to various classes of sufferers such as the elderly, women of childbearing age, and sufferers with concomitant disorders, treated with medications capable of drug interactions. There is a recognition of the value of slow introduction, a preference for monotherapy, recognition of the effects of AEDs on hormones and reproductive function and effects on the fetus exposed to AEDs in utero, comprising physical malformations and effects on cognitive development. A balance between efficacy and safety is pivotal, as every preference about the initial pharmacotherapy of epilepsy and subsequent polytherapy has its protagonists. With improvement in diagnostic techniques and new therapeutic modalities it is likely that in the future, pharmacogenomics and an understanding of pharmacoresistance may influence drug selection for individual patients with epilepsy.

Teratogenicity of antiepileptic drugs: role of drug metabolism and pharmacogenomics

The approach to clinical decision-making pertaining to the use of antiepileptic drugs (AEDs) during pregnancy has relied on previous accumulated experience and, since the 1990s, on data from pregnancy registries. The limitations of this process are that no information regarding the chemical attributes of the AED under consideration, nor the role of a number of enzyme systems that are known to interact with foreign compounds to modify their potential for harm, are included. The role of the hepatic mixed function oxidase system may be especially important in conferring teratogenic risk. However, systems such as epoxide hydrolase, glutathione reductase, superoxide dismutase and other toxin-scavenging systems may be important modifiers that lower the risk. Knowledge is also accumulating on the interactions of AEDs with molecular targets such as histone deacetylase and peroxisome proliferator-activated receptors that may play important roles in teratogenesis. While our knowledge of these factors are incomplete, progress can be achieved by beginning to include these concepts in our discussion on the topic and by promoting research that may improve our ability to individualize the analysis of risk for a specific patient with regards to specific AEDs.

Effect of Dose on the Frequency of Major Birth Defects Following Fetal Exposure to Lamotrigine Monotherapy in an International Observational Study

Data from the International Lamotrigine Pregnancy Registry were analyzed to examine the effect of maximal first-trimester maternal dose of lamotrigine monotherapy on the risk of major birth defects (MBDs). Among 802 exposures, the frequency of MBDs was 2.7% (95% confidence interval [CI] 1.8-4.2%). The distribution of dose did not differ between infants with and those without MBDs (mean 248.3 milligrams per day [mg/day] and 278.9 mg/day, respectively, median 200 mg/day for both groups). A logistic regression analysis showed no difference in the risk of MBDs as a continuous function of dose (summary odds ratio [OR] per 100 mg increase =0.999, 95% CI 0.996-1.001). There was also no effect of dose, up to 400 mg/day, on the frequency of MBDs.