EVALUATION OF THE FETOPLACENTAL FUNCTION BY MEANS OF INTRA-AMNIOTIC ADMINISTRATION OF DEHYDROEPIANDROSTERONE-SULPHATE

It is well know that in pregnancy dehydroepiandrosterone-sulphate (DHEAS) (90% synthetized by the fetal adrenals, 10% by the maternal ones) is converted into estrogens mainly in the placenta. In order to eyaluate the steroid metabolizing capacity of the placental enzymatic complex under load conditions, a test was devised based upon a rapid introduction of 200 mg of DHEAS into the amniotic compartment during the third trimester of gestation. The purpose of the present investigation was to establish the clinical utüity of such a test in comparison with the simple urinary estrogen determination test. After DHEAS administration an increment in maternal urinary excretion of total estrogens was obtained: this increment over the 24 hrs foUowing the DHEA-S injection was assessed äs the percentage of the mean of the two 24 hrs excretion values before DHEA-S administration. The test was performed in 45 pregnancies (12 normal, 33 pathological). In all the normal pregnancies an increment of total urinary estrogens in the first 24 hrs urine exceeding 100% was obtained, with an average of 147,6% ± 46,6 S.D. (Fig. 1). Conventionally, an increment exceeding 100% was considered an indication of normality. In these 12 cases the values of the daily urinary estrogens determinations were within the normal ränge (Tab. I). In 4 of the cases of pathological pregnancies considered, both daily urinary estrogens excretion and estrogens increment after DHEAS administration were below the normal ränge (Tab. II). In 24 cases the daily urinary estrogens excretion was within the normal range or at border line, but the increment after DHEA-S administration neverreached 100% (Tab. UI). The last 5 cases presented low daily urinary estrogens excretion, but a normal increment after DHEA-S administration (Tab. IV). This group collected cases of fetal pathology, in which the synthesis of DHEA-S by the fetal adrenals was probably insufficient, whereas the placental function was normal. In conclusion we consider the intraamniotic DHEA-S test very reliable and maybe more significant than the analogous maternal intravenous DHEA-S test, because utilizing the intraamniotic administration it is possible to obtain a higher increment in estrogens synthetised by the placenta and excreted in maternal urines. It can be used in the case of pregnancies at risk, where the urinary estrogens values are questionable, particulary where there is suspicion of fetal distress, but the urinary estrogens values are within the normal range. © 1979, Walter de Gruyter. All rights reserved.