Elevated serum HCG level after intravenous LH-RH administration in human pregnancies

A dose of 100 micrograms synthetic LH-RH was injected intravenously to six pregnant women and the serum HCG (human chorionic gonadotropin) and serum HCS (human chorionic somatomammotropin) were measured before and after the injection. Significantly elevated HCG levels were detected after the LH-RH administrations. This phenomenon seems to depend on the gestational age. The HCS levels remained unchanged. These data indicate that the actual HCG production during the pregnancy is lower than the maximal capacity of the chorionic tissue, though their gestational age-related patterns are very similar. Furthermore, it is suggested that the placenta (generally accepted as a relatively independent organ) may be controlled by endocrine factors.