THE EFFECT OF THE LONG TERM ADMINISTRATION OF ORAL CONTRACEPTIVES ON EXCRETION VALUES FOR FOLLICLE-STIMULATING HORMONE AND LUTEINISING HORMONE

Abstract

Pituitary gonadotrophic function together with urinary steroid excretion has been studied in 4 women during and following long term therapy with oral contraceptives. Assays of follicle-stimulating hormone (FSH) were performed, in all subjects while luteinising hormone (LH) output was measured in 2. Estimations of urinary estrogens and pregnanediol indicated absence of ovarian activity during treatment and the resumption of ovulation in the first or second post-treatment cycle. In the 3 women who received progestogen-oestrogen mixtures depression of FSH and LH activities during treatment was noted. In the subject receiving a progestogen alone such a depression did not occur. Following withdrawal of medication urinary FSH excretion remained similar to that during treatment while LH levels either rose or were unchanged. It is concluded that the long term effects of oral contraceptives on pituitary gonadotrophic function are variable and may depend on such factors as the composition of the tablet administered, its total dosage and the duration of therapy.