Preliminary results on the role of embryonic human chorionic gonadotrophinin corpus luteum rescue during early pregnancy and the relationship to abortion and ectopic pregnancy

The precise mechanisms by which corpus luteum (CL) function is modulated du ring early pregnancy are not known, Evidence in failed pregnancies (ectopic , abortions), shows that factors other than human chorionic gonadotrophin ( HCG) could be involved in its regulation. The objective of this study was t o investigate the dynamics of beta-HCG, progesterone and oestradiol product ion in early pregnancy and its relation to embryonic quality and topographi c localization, Plasma concentrations of progesterone, oestradiol and beta- HCG were studied between days +12 and +21 after an in-vitro fertilization ( IVF) embryo transfer in 11 intrauterine pregnancies, 10 intrauterine aborti ons and seven tubal pregnancies. Tubal pregnancies and abortions were group ed according to doubling time (DT) of HCG. Results showed that oestradiol c oncentrations were apparently reduced in both ectopic pregnancies and abort ions compared with normal pregnancies. The fall in oestradiol concentration s was seen in ectopic pregnancies with an abnormal DT for HCG and in all ab ortions. When the ectopic pregnancy had a normal DT, oestradiol and progest erone concentrations were normal, In abortions, the fall in oestradiol and progesterone concentrations was less influenced by the DT of HCG. These fin dings suggest that corpus luteum function depends on an adequate DT of HCG more than an absolute value, and with normal trophoblastic tissue the site of implantation does not affect CL function.