Oestrogen modulation of gonadotrophin and prolactin release in women with anovulation and their responses to clomiphene.

An LHRH test was performed before and at both 44 and 92 h after the administration of 2.5 mg oestradiol benzoate in eleven patients with hyperprolactinaemia, eight with idiopathic secondary amenorrhoea and seven with oligomenorrhoea. The basal serum hormone concentrations and the responses to LHRH were compared with the same tests performed on ten normal subjects during the early follicular phase of their menstrual cycles (days 4--6). Mean basal concentrations of oestradiol in each group of patients and oestrone in those with hyperprolactinaemia were significantly lower than in the normal subjects. The mean concentration of prolactin in women with secondary amenorrhoea remained lower than in the normal women throught the tests (P less than 0.05). The LH and FSH responses to LHRH before oestrogen in patients with hyperprolactinaemia and of FSH in those with secondary amenorrhoea, were greater than in the normal subjects (P less than 0.001). After oestrogen treatment the responses were similar in all groups except in those with oligomenorrhoea where LH and FSH responses at 44 h (P less than 0.05 and P less than 0.01 respectively) and LH responses at 92 h (P less than 0.01) were lower than in normal controls. The responses at 92 h in all groups were greater than at 44 h (amplification) but the amplification at 92 h and at 44 h compared to the pre-treatment responses, tended to be lower in each group of patients compared to the normal controls. In the hyperprolactinaemic group of patients there was a negative correlation between the basal prolactin concentration and the gonadotrophin amplifications at 92 h (P less than 0.01), and a positive correlation between the basal oestrone levels and the amplifications at 92 h (P less than 0.01). The results of the oestrogen amplification test in eleven of the non-hyperprolactinaemic anovular patients were compared with the ovulatory response to 100 mg clomiphene given for 5 days. Six showed a normal oestrogen amplification and they all ovulated. Two patients failed to show greater amplification at 92 than at 44 h and required human chorionic gonadotrophin (HCG) as well as clomiphene to ovulate. The other three showed a diminished LH amplification at 92 h; they required 200 mg clomiphene and showed a prolonged follicular phase. The responses of the hyperprolactinaemic patients to clomiphene were poor and there was a negative correlation between prolactin concentration and oestrogen production (P less than 0.01). All ten hyperprolactinaemic patients treated with bromocriptine ovulated and eight conceived. The oestrogen amplification test appears to have some value in predicting the subsequent response to clomiphene in non-hyperprolactinaemic anovular women.