TOLUENE EMBRYOPATHY - DELINEATION OF THE PHENOTYPE AND COMPARISON WITH FETAL ALCOHOL SYNDROME

Objective. To determine if maternal toluene abuse produces any structu ral or developmental disabilities in the developing fetus, a cohort of toluene-exposed infants was ascertained and examined. Methodology. Ei ghteen infants with a history of in utero toluene exposure were examin ed at birth. Nine of these infants were reexamined 3 to 36 months afte r their initial evaluations. The clinical findings in these patients w ere compared with those of similarly exposed children from the literat ure and with patients who had the fetal alcohol syndrome. Results. Thi rty-nine percent of all toluene-exposed in infants described in this a nd other studies were born prematurely, and 9% died during the perinat al period. Fifty-four percent were small for gestational age, and 52% exhibited continued postnatal growth deficiency. A 33% incidence of pr enatal microcephaly, a 67% incidence of postnatal microcephaly, and an 80% incidence of developmental delay were observed. Eighty-three perc ent of the patients had craniofacial features similar to the fetal alc ohol syndrome, and 89% of these children had other minor anomalies. Co nclusions. Data from the patients herein described and the available s cientific literature suggest that the mechanism of alcohol craniofacia l teratogenesis may be nonspecific, with a variety of teratogens, incl uding toluene, giving rise to phenotypic facial abnormalities similar to those of the fetal alcohol syndrome. We propose a common mechanism of craniofacial teratogenesis for toluene and alcohol, namely a defici ency of craniofacial neuroepithelium and mesodermal components due to increased embryonic cell death.