Urinary oestriol after intra-amniotic injection of oestriol sulphate.

Evidence of a foetal role in determining the length of gestation

“…It may be that as pregnancy advances, the increasingly active foetal adrenal uses more progesterone, or its precursors, to synthesize corticosteroids and oestro-gens and thus critically alters the hormonal environment which regulates the activity of the uterus. Alternatively, the vital factor may be increasing oestrogen production by the foetus, for Pinto et al (1966) have demonstrated increased uterine activity following the intra-amniotic injection of oestradiol-17/ in human pregnancy and Klopper, Dennis & Farr (1968) claim a similar effect from oestriol sulphate given by the same route.…”

Oestriol in Amniotic Fluid: A Gas Chromatographic Method

“…When oestriol sulphate is injected into the fluid at term, the steroid can be detected in the mother's urine within 4 hr. (Klopper, Dennis & Farr, 1968). There is thus a reasonable possibility that the oestriol concentration in the amniotic fluid is in equilibrium with that in the foetal circulation.…”

Effect of Intra-amniotic Oestriol Sulphate on Uterine Contractions

“…Intra-amniotic injection of this conjugate is likely to be a more searching test of the physiological activity of the hormone than administration by mouth or parenterally of the free compound. An investigation of the metabolism of oestriol sulphate after its injection into the uterine cavity of women in late pregnancy (Klopper et al, 1968) showed that pharmacological doses were associated with increased uterine activity. In subsequent trials two women at term went into labour, and delivered following the injection of oestriol sulphate into the amniotic cavity.…”