[Endocrine changes following progesterone substitution in early pregnancy]

250 mg hydroxy-progesteronecaproate was used for intramuscular administration in 25 patients, between 11 and 15 week's gestation, presenting either with a history of recurrent abortion or being admitted because of threatened abortion. Beta-HCG and progesterone concentrations were determined twice at intervals of 24 hours. Three women aborted without showing any increase in Beta-HCG levels nore in progesterone levels. In 20 patients Beta-HCG concentrations increased significantly after the medication, whereas only 5 patients showed a rise in progesterone levels. In 14 patients serum progesterone concentrations decreased making the use of progestational steroids in the management of threatened abortion questionable.