115 normotensive healthy primigravidae have been investigated during 28-32 weeks of pregnancy for early detection of pregnancy-induced hypertension (PIH) by performing the roll-over test (ROT) of according to Gant et al. No statistically significant relation was found between a positive supine pressor test and development of PIH. The hydrostatic effect, calculated in 15 of these women, seems to influence the results of the ROT. The other factors which can influence the blood pressure with change of position have also been enumerated.