FETAL DEVELOPMENT IN LATE GESTOSIS AND NICOTINE CONSUMPTION

In pre-eclamptic and in smoking women, the foetus often develops growth retardation. Hence, nicotine as vasoconstrictive substance increases the bloodpressure, therefore causes a higher incidence for pre-eclamptic toxaemia in smoking pregnant women. By means of perinatal inquiry in Baden-Wurttemberg, not only the frequency of preeclamptic toxaemia was proven in smoking women, but also the frequency of toxaemia in mothers with low, of normal and high weight of the newborn. Hypertension is more frequent in mothers with overweight babies than in mothers with babies of normal weight. In case of overweight newborns, toxaemia is less often caused by proteinuria than in underweight babies. Hypertension is less frequent in smoking pregnant women than in non-smoking women. These findings can be explained by a new theory, which interprets pre-eclamptic toxaemia as a compensatory mechanism in foetal growth retardation. For the foetus, which is insufficiently supplied by the placenta, this regulatory mechanism enhances the blood supply of the placenta. The higher incidence of toxaemia in pregnant women with overweight babies is explained by an increased demand on the placenta, which causes a better foetal blood supply of the placenta in developing the toxaemia. In this case, the toxaemia is compensated. In the stage of decompensation with foetal growth retardation, all reserves are mobilised by an increased permeability of the vessels, which leads to an improved passage through the placenta, but also to proteinuria and increased incidence of oedema. In smoking women, the lesion of the foetus sets in early in pregnancy; it remains rather small and so it makes diminished demands on the placenta in late pregnancy. The compensatory mechanism is therefore less necessary.