Comparison of intrafollicular sperm injection and intrauterine insemination in the treatment of subfertility.

Purpose: To compare the efficacy of intrafollicular sperm injection (IFI) versus intrauterine insemination (IUI) in the treatment of subfertility.

Methods: 38 couples suffering primary or secondary subfertility contributed a total of 47 IUI or IFI cycles, 26 by IUI and 21 by IFI. Folliculogenesis, ovulation triggering, and IUI or IFI were performed. Motile spermatozoa were inseminated into the uterine cavity for IUI or injected into pre-ovulatory follicles for IFI. The rate of biochemical and clinical pregnancy was assessed.

Results: The rate of biochemical pregnancy/cycle for IUI was 11 % as compared to 38 % for IFI (p = 0.04). The rate of clinical pregnancy/cycle for IUI was 11 % as compared to 29 % for IFI (p = 0.26). The rate of twin pregnancy and miscarriage was low and no high order multiple gestation was observed. The rate of ectopic tubal pregnancy/cycle for IUI was 0 % as compared to 9 % for IFI (p = 0.19); no ovarian pregnancy was observed. When the analysis was confined to IFI cycles in which 2.68-6.65 million motile spermatozoa were injected/follicle (n = 10), a rate of 60 % clinical pregnancy/cycle was observed, of which 2 were ectopic.

Conclusion: Under the conditions described herein, IFI was more effective than IUI at achieving pregnancy.