DEVELOPMENT OF THE FETAL RAT ADRENAL IN PROLONGED PREGNANCY

Abstract

The adrenals of rat fetuses obtained from mothers whose pregnancy was prolonged by daily injections of 25 mg of progesterone were compared with those of fetuses in normal pregnancy and of neonatals, with particular reference to the weight, ascrobic acid content and histology. During normal pregnancy, the fetal adrenal gained weight steadily up to the 21st day. From the 21st to 22nd days there was no reliable increase in adrenal weight. Ascorbic acid content increased on the 22nd day of pregnancy showing little fluctuation after birth. Osmiophilic lipids increased in amount. When pregnancy was prolonged for 2-3 days, the fetal adrenals did not show atrophy, but gained weight with a fall in ascrobic acid content. Osmiophilic lipids were fewer than in normal neonatals. It is concluded that the retardation of fetal adrenal growth does not occur in prolonged pregnancy,.