Within the last 3 years a prospective study on 70 pregnant women suffering from hypotension was carried out. In all these patients the endocrine placental function was examined regularly by measuring the HPL and E3 level in the maternal serum (from the 16th week of pregnancy onwards). In order to get information on the uteroplacental perfusion rate, placental flow measurements using radioisotopes were carried out. Whereas the endocrine parameters revealed no abnormality, the results of the flow measurements were significantly low in more than 80%. In 30 out of the total of 70 patients no medication was given and after termination of pregnancy the fetal outcome was investigated. The neonates of this group were significantly smaller than normal, the rate of dystrophy was considerably high. The other 40 women were subjected to a drug regimen. Depending on pressure values and type of complaints they were given a crystal suspension of deoxycorticosterone trimethylacetate intramuscularly. In this group of patients the placental perfusion rate improved significantly after medication, the fetal outcome did not differ in comparison to cases with normotension. In the light of our study we suggest that a maternal blood pressure of 110/65 and below has to be treated not only because of maternal indication, but as well because of the fetus' sake.