[Ventricular activation time of the fetal heart]

The prenatal risk determined by smoking pregnant woman was studied by a fetal electrocardiogram at different gestational ages. There were 28 low risk pregnancy women selected and qualified by means of an 80% completion of the Perechtl optimal criterion, 13 which smoked more than 5 cigarettes daily and 15 (53%) non-smokers. A new computerized technique was defined and applied for recording a continuous fetal electrocardiogram for long periods of time. Measurements of the QRS complex, inscription time of the intrinsecoid deflection (TIDI) and intrinsecoid deflection (DI) lengths were taken and compared with the gestational age. It was observed that there is a relationship of statistical significance (p less than 0.005) between the gestational age and the QRS length in the nonsmoking women. This relationship was smaller in the smoking group and furthermore it was negative when comparing the gestational age with the TIDI. There was no statistical difference in the weight of the child at birth in both groups, nevertheless the fetal electrocardiogram is useful in determining the development of the ventricular mass. In the smoking group the lack of relationship between the QRS length and the gestational age is probably owing to the retarded cardiac development and expressed ahead of all other features in fetal growth including low weight at birth.