[Concentrations of growth hormone, prolactin and thyroid-stimulating hormone in the maternal, fetal and amniotic...

GH, PRL and TSH in the maternal, fetal and amniotic compartments were measured by radioimmunoassay in normal pregnant women (group I, n = 16) and patients with anencephalic fetuses (group II, n = 10). The concentrations of GH (20.6 +/- 8.5 ng/ml, mean +/- SD) in cord blood of normal fetuses were significantly higher (p less than 0.001) than those (5.1 +/- 3.5 ng/ml) in anencephalic fetuses. Both maternal PRL levels in group I and group II were lower than their respective cord bloods. The concentrations of PRL (283.1 +/- 127.5 ng/ml) in normal fetuses were higher, but not significantly, than those (199.4 +/- 111.8 ng/ml) in anencephalic fetuses. Also, compared with PRL levels in the maternal and cord blood, those in amniotic fluid were significantly higher (p less than 0.001) in both groups. On the contrary, GH and TSH levels in amniotic fluid were much lower than those in the maternal and fetal blood. The concentration of TSH (10.2 +/- 4.6 microU/ml) in normal fetuses was significantly higher (p less than 0.05) than those (7.1 +/- 3.1 microU/ml) in maternal blood, but not significantly different from those (11.3 +/- 3.6 microU/ml) in anencephalic fetuses. These results suggest that GH, PRL and TSH do not cross human placenta and biosyntheses of these hormones in the maternal and fetal pituitaries are independent.