Congenital abnormalities of 88 children born to mothers who attempted suicide with phenobarbital during pregnany: the use of a disaster epidemiological model for the evaluation of drug teratogenicity.

OBJECTIVE: To study the effect of large doses of phenobarbital used for a suicide attempt during pregnancy for fetuses to estimate the teratogenic potential of phenobarbital.

DESIGN AND SETTING: Comparative analysis of exposed children and their unexposed sibs born to pregnant patients who attempted suicide during pregnancy and admitted to the toxicological inpatient clinic, Budapest, 1960-1993.

STUDY PARTICIPANTS: Of 1044 self-poisoned pregnant women, 88 used phenobarbital for suicide attempt and delivered newborn babies.

MAIN OUTCOME MEASURES: Structural birth detects, i.e., congenital abnormalities (CAs).

RESULTS: Doses ranged between 400 and 3000 mg of phenobarbital in 88 pregnant women who attempted suicide with this drug during pregnancy and later delivered live-born babies. Twelve (13.6%) of 88 exposed children and eight (10.3%) of 78 sibs were affected with CAs (odds ratios (OR) with 95%CI: 1.4, 0.6-3.5). Of 88 exposed children, 34 were born to mothers who attempted suicide with phenobarbital between the 3rd and 12th postconceptional weeks, the critical period of most CAs; 3 had CAs (diaphragmatic defect, multiple CA, undescended testis), but only diaphragmatic defect might be associated with phenobarbital used for suicide attempt.

CONCLUSIONS: The use of phenobarbital once but extremely large doses in non-epileptic pregnant women does not seem to pose a significant risk for CAs. Our experiences show the feasibility and benefits of the disaster epidemiological self-poisoning model for estimating human teratogenic risks of drug exposure.