[The studies of the estrogen and progesterone receptor levels in the placenta, fetal membrane, uteroplacental bed and myometrium in patients with prolonged pregnancy].

OBJECTIVE

To reveal the relation between the changes of the estrogen receptor (ER) and progesterone receptor (PR) levels in the target tissues and the duration of pregnancy.

METHODS

The method combining fluorescence with hormones and polyspectrum-data system were used to qualitatively and quantitatively assay the estrogen and progesterone receptor concentrations in the placenta, fetal membrane, uteroplacental bed and uterine myometrium in 30 cases with prolonged pregnancy and 27 cases of term pregnancy.

RESULTS

ER concentrations in the uteroplacental bed and fetal membrane of the prolonged pregnancy group were markedly lower than that in the term group; ER/PR values in every target tissues of the prolonged pregnancy were much less than that in the term group. There is a positive relationship between ER and PR levels in all target tissues evidently; and ER/PR value in the lower segment of the uterine myometrium in the group with uterine contraction were significantly higher than that of group without uterine contraction.

CONCLUSIONS

The mechanisms of both prolonged pregnancy and onset of labour were revealed partly in this study. The cause of prolonged pregnancy is relatively concerned with the decline of ER levels and the ascent of the PR concentrations in the target tissues. Also the uterine contraction is induced by the increase of ER and decrease of PR.