Lewis B. Holmes

The Teratogenicity of Anticonvulsant Drugs

BACKGROUND The frequency of major malformations, growth retardation, and hypoplasia of the midface and fingers, known as the anticonvulsant embryopathy, is increased in infants exposed to anticonvulsant drugs in utero. However, whether the abnormalities are caused by the maternal epilepsy itself or by exposure to anticonvulsant drugs is not known. METHODS We screened 128,049 pregnant women at delivery to identify three groups of infants: those exposed to anticonvulsant drugs, those unexposed to anticonvulsant drugs but with a maternal history of seizures, and those unexposed to anticonvulsant drugs with no maternal history of seizures (control group). The infants were examined systematically for the presence of major malformations, signs of hypoplasia of the midface and fingers, microcephaly, and small body size. RESULTS The combined frequency of anticonvulsant embryopathy was higher in 223 infants exposed to one anticonvulsant drug than in 508 control infants (20.6 percent vs. 8.5 percent; odds ratio, 2.8; 95 percent confidence interval, 1.1 to 9.7). The frequency was also higher in 93 infants exposed to two or more anticonvulsant drugs than in the controls (28.0 percent vs. 8.5 percent; odds ratio, 4.2; 95 percent confidence interval, 1.1 to 5.1). The 98 infants whose mothers had a history of epilepsy but took no anticonvulsant drugs during the pregnancy did not have a higher frequency of those abnormalities than the control infants. CONCLUSIONS A distinctive pattern of physical abnormalities in infants of mothers with epilepsy is associated with the use of anticonvulsant drugs during pregnancy, rather than with epilepsy itself.

Practice Parameter update: Management issues for women with epilepsy—Focus on pregnancy (an evidence-based review): Teratogenesis and perinatal outcomes Report of the Quality Standards Subcommittee and Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and American Epilepsy Society

Objective: To reassess the evidence for management issues related to the care of women with epilepsy (WWE) during pregnancy. Methods: Systematic review of relevant articles published between January 1985 and June 2007. Results: It is highly probable that intrauterine first-trimester valproate (VPA) exposure has higher risk of major congenital malformations (MCMs) compared to carbamazepine and possible compared to phenytoin or lamotrigine. Compared to untreated WWE, it is probable that VPA as part of polytherapy and possible that VPA as monotherapy contribute to the development of MCMs. It is probable that antiepileptic drug (AED) polytherapy as compared to monotherapy regimens contributes to the development of MCMs and to reduced cognitive outcomes. For monotherapy, intrauterine exposure to VPA probably reduces cognitive outcomes. Further, monotherapy exposure to phenytoin or phenobarbital possibly reduces cognitive outcomes. Neonates of WWE taking AEDs probably have an increased risk of being small for gestational age and possibly have an increased risk of a 1-minute Apgar score of <7. Recommendations: If possible, avoidance of valproate (VPA) and antiepileptic drug (AED) polytherapy during the first trimester of pregnancy should be considered to decrease the risk of major congenital malformations (Level B). If possible, avoidance of VPA and AED polytherapy throughout pregnancy should be considered to prevent reduced cognitive outcomes (Level B). If possible, avoidance of phenytoin and phenobarbital during pregnancy may be considered to prevent reduced cognitive outcomes (Level C). Pregnancy risk stratification should reflect that the offspring of women with epilepsy taking AEDs are probably at increased risk for being small for gestational age (Level B) and possibly at increased risk of 1-minute Apgar scores of <7 (Level C).

Malformations Due to Presumed Spontaneous Mutations in Newborn Infants

We conducted hospital-based surveillance of congenital malformations to determine the rate of apparently spontaneous single mutations leading to recognized phenotypes. Through surveillance of 69,277 infants with gestational ages of at least 20 weeks, we identified 48 infants (0.07 percent) with major malformations, with phenotypes that suggested that the malformations were due to single mutant genes. Family studies suggested that 11 of these infants (10 with autosomal dominant disorders and 1 with an X-linked condition) were affected as the result of a new (spontaneous) genetic mutation. The spontaneous mutation rates per gene were 0.7 x 10(-5) and 1.44 x 10(-5) for the disorders in which one and two infants were affected, respectively. In addition, 5 of the 10 infants with autosomal recessive malformations had negative family histories, but we were unable to infer the presence of spontaneous mutations in these cases. Because the family history was negative in 44.4 percent of the infants with disorders considered due to autosomal or X-linked genes, counseling should include the understanding that genetic disorders often occur unexpectedly among children of healthy parents.

Etiologic Heterogeneity of Neural-Tube Defects

We classified 106 stillborn and live-born infants with anencephaly, meningomyelocele, meningocele and encephalocele according to the recognized causes of these malformations. Six different causes were identified, including both genetic and nongenetic disorders; 12 per cent had nongenetic disorders, a chromosome abnormality, or an encephalocele as part of the autosomal recessive Meckel syndrome. Therefore, for this 12 per cent genetic counseling normally provided for isolated anencephaly, meningomyelocele or encephalocele would have been incorrect. If all infants were considered together regardless of cause, the precurrence and recurrence rates of similar malformations in the sibs were 5.2 and 1.7 per cent respectively. However, if infants with other disorders, especially the Meckel syndrome, were excluded, the precurrence and recurrence rates for isolated anencephaly, meningomyelocele and encephalocele among white infants were only 1.7 per cent and 0 per cent. These rates are much lower than the risk of 5 per cent currently being used in genetic counseling in the United States.

Metabolic Control and Progression of Retinopathy: The Diabetes in Early Pregnancy Study

OBJECTIVE To evaluate the role of metabolic control in the progression of diabetic retinopathy during pregnancy. RESEARCH DESIGN AND METHODS We conducted a prospective cohort study of 155 diabetic women in the Diabetes in Early Pregnancy Study followed from the periconceptional period to 1 month postpartum. Fundus photographs were obtained shortly after conception (95% within 5 weeks of conception) and within 1 month postpartum. Glycosylated hemoglobin was measured weekly during the 1st trimester and monthly thereafter. RESULTS In the 140 patients who did not have proliferative retinopathy at baseline, progression of retinopathy was seen in 10.3, 21.1, 18.8, and 54.8% of patients with no retinopathy, microaneurysms only, mild nonproliferative retinopathy, and moderate-to-severe nonproliferative retinopathy at baseline, respectively. Proliferative retinopathy developed in 6.3% with mild and 29% with moderate-to-severe baseline retinopathy. Elevated glycosylated hemoglobin at baseline and the magnitude of improvement of glucose control through week 14 were associated with a higher risk of progression of retinopathy (adjusted odds ratio for progression in those with glycohe-moglobin ≥ 6 SD above the control mean versus those within 2 SD was 2.7; 95% confidence interval was 1.1-7.2; P = 0.039). CONCLUSIONS The risk for progression of diabetic retinopathy was increased by initial glycosylated hemoglobin elevations as low as 6 SD above the control mean. This increased risk maybe due to suboptimal control itself or to the rapid improvement in metabolic control that occurred in early pregnancy. Excellent metabolic control before conception may be required to avoid this increase in risk. Those with moderate-to-severe retinopathy at conception need more careful ophthalmic monitoring, particularly if their diabetes was suboptimally controlled at conception.

Novel HOXA13 Mutations and the Phenotypic Spectrum of Hand-Foot-Genital Syndrome

Hand-foot-genital syndrome (HFGS) is a rare, dominantly inherited condition affecting the distal limbs and genitourinary tract. A nonsense mutation in the homeobox of HOXA13 has been identified in one affected family, making HFGS the second human syndrome shown to be caused by a HOX gene mutation. We have therefore examined HOXA13 in two new and four previously reported families with features of HFGS. In families 1, 2, and 3, nonsense mutations truncating the encoded protein N-terminal to or within the homeodomain produce typical limb and genitourinary abnormalities; in family 4, an expansion of an N-terminal polyalanine tract produces a similar phenotype; in family 5, a missense mutation, which alters an invariant domain, produces an exceptionally severe limb phenotype; and in family 6, in which limb abnormalities were atypical, no HOXA13 mutation could be detected. Mutations in HOXA13 can therefore cause more-severe limb abnormalities than previously suspected and may act by more than one mechanism.

Management issues for women with epilepsy—Focus on pregnancy (an evidence-based review): II. Teratogenesis and perinatal outcomes Report of the Quality Standards Subcommittee and Therapeutics and Technology Subcommittee of the American Academy of Neurology and the American Epilepsy Society

A committee assembled by the American Academy of Neurology (AAN) reassessed the evidence related to the care of women with epilepsy (WWE) during pregnancy, including antiepileptic drug (AED) teratogenicity and adverse perinatal outcomes. It is highly probable that intrauterine first‐trimester valproate (VPA) exposure has higher risk of major congenital malformations (MCMs) compared to carbamazepine (CBZ), and possibly compared to phenytoin (PHT) or lamotrigine (LTG). It is probable that VPA as part of polytherapy and possible that VPA as monotherapy contribute to the development of MCMs. AED polytherapy probably contributes to the development of MCMs and reduced cognitive outcomes compared to monotherapy. Intrauterine exposure to VPA monotherapy probably reduces cognitive outcomes and monotherapy exposure to PHT or phenobarbital (PB) possibly reduces cognitive outcomes. Neonates of WWE taking AEDs probably have an increased risk of being small for gestational age and possibly have an increased risk of a 1‐minute Apgar score of <7. If possible, avoidance of VPA and AED polytherapy during the first trimester of pregnancy should be considered to decrease the risk of MCMs. If possible, avoidance of VPA and AED polytherapy throughout pregnancy should be considered and avoidance of PHT and PB throughout pregnancy may be considered to prevent reduced cognitive outcomes.

Predictive value of minor anomalies. I. Association with major malformations.

We examined 4305 white newborn infants for 114 minor physical features and major malformations to evaluate the hypothesis that the presence of three or more minor anomalies is highly predictive of a major malformation. We confirmed that the infant with three or more minor anomalies is at increased risk for a major malformation. However, this risk (19.6%) was much lower than the risk of 90% popularized by Smith and based on the study of Marden et al. (J Pediatr 1964;64:357). Analysis of the findings in the two studies showed that the lower predictive value was probably related to differences in study design. Nevertheless, some minor anomalies remain essential to the early recognition of several serious malformation syndromes.

Familial Nature of Congenital Absence and Severe Dysgenesis of Both Kidneys

Seventy-one parents and 40 siblings of 41 index patients with bilateral renal agenesis, bilateral severe dysgenesis, or agenesis of one kidney and dysgenesis of the other were evaluated by gray-scale ultrasonography for genitourinary malformations. Nine per cent (10 of 111) had asymptomatic renal malformations, most often unilateral renal agenesis (4.5 per cent--a frequency that was significantly higher than the frequency of 0.3 per cent among 682 adults [P less than 0.004]). We recommend ultrasonographic screening for parents and siblings of infants born with agenesis or dysgenesis of both kidneys or with agenesis of one kidney and dysgenesis of the other, since renal malformations may have medical implications even for asymptomatic patients.

Antidepressant Use in Pregnancy and the Risk of Cardiac Defects

BACKGROUND Whether the use of selective serotonin-reuptake inhibitors (SSRIs) and other antidepressants during pregnancy is associated with an increased risk of congenital cardiac defects is uncertain. In particular, there are concerns about a possible association between paroxetine use and right ventricular outflow tract obstruction and between sertraline use and ventricular septal defects. METHODS We performed a cohort study nested in the nationwide Medicaid Analytic eXtract for the period 2000 through 2007. The study included 949,504 pregnant women who were enrolled in Medicaid during the period from 3 months before the last menstrual period through 1 month after delivery and their liveborn infants. We compared the risk of major cardiac defects among infants born to women who took antidepressants during the first trimester with the risk among infants born to women who did not use antidepressants, with an unadjusted analysis and analyses that restricted the cohort to women with depression and that used propensity-score adjustment to control for depression severity and other potential confounders. RESULTS A total of 64,389 women (6.8%) used antidepressants during the first trimester. Overall, 6403 infants who were not exposed to antidepressants were born with a cardiac defect (72.3 infants with a cardiac defect per 10,000 infants), as compared with 580 infants with exposure (90.1 per 10,000 infants). Associations between antidepressant use and cardiac defects were attenuated with increasing levels of adjustment for confounding. The relative risks of any cardiac defect with the use of SSRIs were 1.25 (95% confidence interval [CI], 1.13 to 1.38) in the unadjusted analysis, 1.12 (95% CI, 1.00 to 1.26) in the analysis restricted to women with depression, and 1.06 (95% CI, 0.93 to 1.22) in the fully adjusted analysis restricted to women with depression. We found no significant association between the use of paroxetine and right ventricular outflow tract obstruction (relative risk, 1.07; 95% CI, 0.59 to 1.93) or between the use of sertraline and ventricular septal defects (relative risk, 1.04; 95% CI, 0.76 to 1.41). CONCLUSIONS The results of this large, population-based cohort study suggested no substantial increase in the risk of cardiac malformations attributable to antidepressant use during the first trimester. (Funded by the Agency for Healthcare Research and Quality and the National Institutes of Health.).