Infertility: Predicting and optimizing success in an intra-uterine insemination programme

We analysed 381 consecutive cycles of homologous intra-uterineinsemination (IUI) in 215 infertile couples, resulting in 48pregnancies (12.6%/cycle, 22.3/patient). Cycle fecundity rangedfrom 0.11 to 0.14 in women aged 25–39 years, falling to0.04 beyond age 40 years. Of the 48 pregnancies, 43 occurredin the first three treatment cycles, in which fecundity was0.14, 0.16 and 0.10 respectively. Beyond three cycles, fecunditywas 0.07 (P = 0.05 versus first two cycles). The occurrenceof pregnancy varied with diagnosis (P = 0.04). Fecundity wassignificantly greater for women with ovulatory dysfunction (0.30)than for endometriosis, male factor, tubal factor, idiopathicinfertility or multifactorial (0.08–0.14). Ovulation inductionusing menopausal gonadotrophins offered significant advantageover natural cycles or cycles using clomiphene citrate withoutgonadotrophins (0.15 versus 0.03, P = 0.01). Cycles in whichpre-ovulatory surges were either induced or supported with humanchorionic gonadotrophin (HCG) were superior to spontaneous luteinizinghormone surges (0.13 versus 0.03, P = 0.05). Recruitment ofat least two mature (>1.6 cm) follicles was critical. Onlyone pregnancy occurred in 64 cycles characterized by one maturefollicle, compared with a pregnancy rate of 0.15 in cycles characterizedby two or more mature follicles (P = 0.006). IUI is not beneficialto women >40 years old, and has the best chance of successwithin three cycles. Multiple follicle recruitment using gonadotrophin-basedstimulation protocols and mid-cycle HCG are necessary to achievean acceptable pregnancy rate.