[Studies on changes in serum estrone, estradiol, estriol, DHA-S, and cortisol and urinary estriol excretion]

Radioimmunoassay was used in order to investigate changes in steroid hormone, serum estrone, estradiol, estriol, dehydroepiandrosterone-sulfate (DHA-S) and cortisol in 71 cases of twin pregnancies. Also, urinary estriol was measured by the Amberlite XAD-2 method. These results were compared with those in 90 cases of single pregnancies. In the third trimester, the increase in serum estrogen levels in twin pregnancies was significantly higher than that in single pregnancies. From 28 to 34 weeks of pregnancy, the DHA-S level in single pregnancies rapidly dropped and after that, gradually decreased to the base level. But in the other weeks of pregnancy, no change in DHA-S was observed. The serum cortisol level in twin pregnancies was slightly higher than in single pregnancies. There was no significant difference between them. The nse in the cortisol level in twin pregnancies was significantly greater than in single pregnancies after 38 weeks of pregnancy. The urinary estriol level in twin pregnancies was significantly higher than in single pregnancies and had values 1.8-3.0 times higher than in single pregnancies.