Interference in follicular maturation following acute intranasal LH-RH agonist administration during mid and late follicular phase.

A dose of 300 micrograms of Buserelin was insufflated into the nose twice on a single day between days 5 and 14 in 23 regularly ovulating volunteers, for a total of 25 cycles. The acute gonadotropin response to the first dosing at 8 A.M. was maximal on treatment days 9 to 14 and was followed by a 2- to 10-fold increase in serum estradiol at 10 A.M. and 2 P.M. The response to the second dosing 10 hours later (6 P.M.) was preserved on treatment days 5 to 8, but was diminished on treatment days 9 to 14. Daily endocrine determinations of serum LH, FSH, estradiol, and progesterone revealed three different situations, according to the time of treatment: In 6 cycles (24%), LH-RH agonist treatment on days 5 to 8 was associated with a delayed LH surge, followed by a normal or short luteal phase; when Buserelin was administered between days 7 and 11 in 16 cycles (64%), there was not subsequent LH surge--progesterone remained in the follicular phase range in 9 cycles, and inadequate secretion of serum progesterone was found along with a luteinized follicle in 5 cycles, being in the luteal phase range in only 2 cycles; in three cycles (12%), the treatment coincided with a presumptive LH surge, and the luteal phase was deficient in two cases. There were no clinical side effects of treatment. Immediate posttreatment cycles were normal. Acute intranasal LH-RH agonist administration predominantly delayed ovulation when administered at midfollicular phase, and interfered with final follicular maturation when given in the late follicular phase.(ABSTRACT TRUNCATED AT 250 WORDS)