Alberto De la Vega

Responsiveness of L-S Ratio of the Amniotic Fluid To Intra-Amniotic Administran of Thyroxine: Role of fetal age

Since 1982 we have accelerated fetal maturation with intra‐amniotic thyr‐oxine (T4) in more than 140 patients. The purpose of this analysis was to determine the rate of change of the ratio of lecithin to sphingomyelin (LIS) after administration of T4 at different gestational ages, and to compare the responses to the first and the second administration of T4. Fifty‐nine cases in which administration of T4 was continued for 2 weeks or more, and in which at least 3 determinations of L/S had been performed, were identified. Gestational age of the fetus at the inititiation of treatment ranged from 26 to 31 weeks (mean 29.3 weeks). Thyroxine was administered weekly in 200 to 500 mcg doses.

Presence of the 5,10-methylenetetrahydrofolate reductase C677T mutation in Puerto Rican patients with neural tube defects.

Folic acid supplementation can reduce the incidence of neural tube defects. The first reported genetic risk factor for neural tube defects is a C677T mutation in the 5,10-methylenetetrahydrofolate reductase gene, resulting in decreased activity of the enzyme. We examined the enzyme mutation role of methylenetetrahydrofolate reductase in the etiology of neural tube defects in our population. The study group consisted of 204 Puerto Rican individuals including 37 pregnant females with a prenatal diagnosis of neural tube defects in their fetuses, 31 newborns, 36 fathers, and 100 healthy adults. The prevalence of the C677T mutation was examined. Homozygosity for the alanine to valine substitution (TT) was observed in 9% of the controls and 19% of the mothers with children with neural tube defects. Our results indicate that the presence of the T allele at the methylenetetrahydrofolate reductase 677 position may increase the risk of giving birth to an infant with a neural tube defect. (J Child Neurol 2002;17:30-32).