The risk of premature birth is high both in serious maternal diseases (immune and autoimmune diseases, neoplasties, infectious diseases), and in obstetrical complications: gestational hyper blood pressure, preeclampsy, uterine-placental apoplexy, placenta praevia. The intensity of the hemorrhage determined by the breaking of the spiraled arterioles of the decidua basalis also causes the placental abruption and the forming of the retroplacental hematoma. In the uteroplacental apoplexy, the retroplacental hematoma is formed while the fetus is still in the uterus. Placenta praevia with bleeding, together with the utero-placental apoplexy and uterine rupture, are serious obstetrical complications and they require urgent interventional therapy. Arterial hyper blood pressure (HBP) is a determinant factor for the onset of serious obstetrical complications: eclampsy, retroplacental hematoma, HELLP syndrome, restriction of intrauterine growth, prematurity, in utero fetal death. The purpose of this paper was to emphasize the materno-fetal prognosis in various circumstances of pathology associated to pregnancy or to obstetrical complications. The patients presenting gestational hyper blood pressure and those suffering from preeclampsy have had a good materno-fetal prognosis. The fetal prognosis depends on the gestational age, on the weight and on the degree of fetal maturation. The results in the cases with utero-placental apoplexy are satisfactory as regards the vital maternal prognosis, and unfavorable as regards the fetal prognosis. The fetal-maternal prognosis in patients with placenta praevia has been good, but it depended on the gestational age when the hemorrhage occurred, and on the degree of fetal maturation.