Efficacy of superovulation and intrauterine insemination in the treatment of infertility

Background Induction of superovulation with gonadotropins and intrauterine insemination are frequently used to treat infertility. We conducted a large , randomized, controlled clinical trial of these treatments. Methods We studied 932 couples in which the woman had no identifiable infer tility factor and the man had motile sperm. The couples were randomly assig ned to receive intracervical insemination, intrauterine insemination, super ovulation and intracervical insemination, or superovulation and intrauterin e insemination. Treatment continued for four cycles unless pregnancy was ac hieved. Results The 231 couples in the group treated with superovulation and intrau terine insemination had a higher rate of pregnancy (33 percent) than the 23 4 couples in the intrauterine-insemination group (18 percent), the 234 coup les in the group treated with superovulation and intracervical insemination (19 percent), or the 233 couples in the intracervical-insemination group ( 10 percent). Stratified, discrete-time Cox proportional-hazards analysis sh owed that the couples in the group treated with superovulation and intraute rine insemination were 3.2 times as likely to become pregnant as those in t he intracervical-insemination group (95 percent confidence interval, 2.0 to 5.3) and 1.7 times as likely as those in the intrauterine-insemination gro up (95 percent confidence interval, 1.2 to 2.6). The couples in the intraut erine-insemination group and in the group treated with superovulation and i ntracervical insemination were nearly twice as likely to conceive as those in the intracervical-insemination group. Conclusions Among infertile couples, treatment with induction of superovula tion and intrauterine insemination is three times as likely to result in pr egnancy as is intracervical insemination and twice as likely to result in p regnancy as is treatment with either superovulation and intracervical insem ination or intrauterine insemination alone. (N Engl J Med 1999; 340:177-83. ) (C) 1999, Massachusetts Medical Society.