The Effects Of Different Dose And Time Of Mifepristone On The Effectiveness Of Medical Abortion And The Expression Of Steroid Hormone Receptor In Human Decidua In Early Pregnancy

OBJECTIVES:To compare 100mg and 200mg oral mifepristone followed by 800ug vaginal misoprostol either 24(±2)hours or 48(±2)hours later, when used for the termination of early pregnancy in women with a length of amenorrhoea of ≤ 49 days, 50~56 days and 57-63 days, and investigate the expression of progesterone receptor (PR), estrogen receptor(ER), glucocorticoid receptor(GR) in human first trimester deciduas and whether such expression was altered after mifepristong treatment in three different gestational period. To investigate the clinical and basal feasibility to exceed the limit of medical abortion in early pregnancy. METHODS:One hundred and fifty women who requested termination of early pregnancy of up to 63 days from last menses were allocated randomly to five different treatment groups:1. vacuum aspiration;2.100mg of mifepristone followed by 800ug misoprostol vaginally 24(±2)hours later;3. lOOmg of mifepristone followed by 800ug misoprostol vaginally 48(±2)hours later;4. 200mg of mifepristone followed by 800ug misoprostol vaginally 24(±2)hours later;5. 200mg of mifepristone followed by 800ug misoprostol vaginally 48(±2)hours later. The four medical abortion regimens were compared in respect of : (1) their effectiveness to induce complete abortion in relation to the length of amenorrhoea;(2) the frequency of side effects;(3) the duration of vaginal bleeding after medical abortion ;(4) the recycle of the first menses after medical abortion.which were compared in three different gestational period: ≤49 days, 50-56 days and 57-63 days. Immunohistochemistry was usedto detect the expression of PR, ER and GR in decidual tissue after abortion. RESUITS:There were not difference in their effectiveness to induce complete abortion, the duration of vaginal bleeding after medical abortion and the recycle of the first menses after medical abortion of the four medical abortion regimens in early pregnancy of ^49 days, 50-56 days and 57-63 days from the last menses. The frequencies of vaginal bleeding after oral mifepristone of the two 48h groups were higher than the two 24h groups. Women in the two 24h groups felt lower abdominal pain more often than the ones in the two 48h groups after vaginal misoprostpl. The two differences are evidence different. PR was widely expressed in stromal cells .spiral arterial wall cells and the gland cells from basal layer of the decidua, but was negative in the gland cells from superficial layer of the decidua. whereas ER was expressed in scattered stromal cells, gland cells and arterial cells. The expression of PR and ER were not affected by mifepristone treatment. GR was expressed moderately in decidual stromal cells and gland cells. The expression of GR in decidual stromal cells was suppressed by mifepristone treatment, the effect was detectable at 24h at least and persisted at 48h and had no relationship to the dose and time of mifepristone. The expression of PR, ER and GR and the suppressive effect of mifepristone on GR had no relationship to gestational period. CONCLUSION: Oral mifepristone lOOmg or 200mg combine with vaginal misoprostol 800ug has the similar safety and effectiveness for termination early pregnancy of^49 days, 50-56 days and 57-63 days from last menses, which suggested the clinical feasibility of exceed the limit of medical abortion in early pregnancy. And lOOmg mifepristone is likely to be cheaper than 200mg and a 24-hour interval...