Pregnancy induced hypertension (PIH) is major contributor to maternal death in developing countries. Endothelin-1 (ET-1) is the most potent vasoconstriction agent known and its serum levels are increased in PIH. Therefore it is important to elucidate maternal and neonatal factors which influence endothelin-1 serum levels. 100 pathological pregnancies and 88 controls were analyzed for blood endothelin-1 and their anthropometric and clinical data were collected. In maternal blood ET-1 levels were strongly predicted by diagnosis, therapy and BMI, while umbilical cord ET-1 levels were strongly predicted by gestational age, therapy and delivery termination. Positive correlation between BMI and ET-1 levels suggest that obese pregnant women have increased risk for cardiovascular diseases. Inverse relationship between Apgar and umbilical ET-1 indicates that ET-1 could be considered as a prognostic marker in cases of neonatal asphyxia.