The infant mortality in specific hypertensive disease of pregnancy and in essential hypertension

Abstract During a 15 year period ending May, 1950, 27,028 patients were delivered in the Obstetrical Department of Bellevue Hospital. Fourteen hundred of these were complicated by some hypertensive condition. This produced an incidence of hypertension of 5.1 per cent. The hypertensive patients were grouped in accordance with a classification previously reported. The type and incidence of these hypertensive conditions were: specific hypertensive disease (pre-eclampsia and eclampsia) 72 per cent; essential hypertension antedating pregnancy 20.8 per cent; glomerulonephritis 1.6 per cent; and unclassified 6.3 per cent. Thirty per cent of the patients with essential hypertension developed specific hypertensive disease. The infant mortality (stillbirths and neonatal deaths) in specific hypertensive disease was compared with that occurring in essential hypertension. It was 2½ times as great in the former condition and 3 times as great in the latter when compared with the loss sustained in the nonhypertension group. The severity of the hypertensive condition influenced the infant mortality. The loss in mild specific disease was only slightly above that in the nonhypertension group. However, it was 4 times as great in the severe cases. The infant mortality in uncomplicated essential hypertension was double that in nonhypertension, but it was increased 5 times when specific hypertensive disease developed. A similar pattern of the effect of severity of disease was noted in the corrected incidence of stillbirths. Intrauterine deaths were assumed to be due to the hypertensive condition after fetal abnormalities, erythroblastosis, prolapsed cord, and obstetrical trauma were ruled out. These losses were greater in severe specific disease than in the mild cases and in essential hypertension with pre-eclampsia or eclampsia. Fetal autopsies revealed either extreme degrees of maceration and/or autolysis or evidence of asphyxia. The incidence of premature separation of the placenta and prematurity was increased when the hypertensive state was severe. These conditions in turn affected the infant mortality. The development of eclampsia in the group with specific hypertension produced an infant loss 3½ times greater than that occurring in patients without convulsions. Among the essential hypertensive patients, only 2 developed convulsive seizures and thus did not influence the infant mortality. This low incidence was attributed to a policy of regular and frequent hospital admissions during the antepartum period in other than the mild cases. Added to this was the rigid adherence to the indications for artificial termination of pregnancy. The cesarean section rate was increased. It was approximately 2½ times as great in specific hypertensive disease and 3 times as frequent in essential hypertension as in the nonhypertension group. In the former, the sections were performed in a large measure for premature separation of the placenta and for threatening eclampsia. In the latter they were chiefly done to lessen the hazards to the mother because of the added specific hypertension. The incidence of tubal ligation was markedly increased in the patients with essential hypertension and unaltered in the group with specific hypertensive disease. The occurrence of premature separation of the placenta and the incidence of prematurity were increased by both hypertensive conditions. Their onset was not influenced by mild specific hypertensive disease and uncomplicated essential hypertension. On the other hand, the increased occurrence developed in the group with severe specific disease and in those with essential hypertension who developed pre-eclampsia. Almost all of the infants were lost in the cases of placental separation. Eighty per cent of the prematures that succumbed in the neonatal period did so within the first 48 hours of life. The increased weight of the live premature infant favorably influenced his chance for survival.