NEW ORLEANS — Women in their 30s with unexplained infertility do not achieve higher live birth rates when treated with unstimulated intrauterine insemination or clomiphene, compared with expectant management, according to results of a study presented at the annual meeting of the American Society for Reproductive Medicine.
The findings suggest that in some groups of women with unexplained infertility, the option of no treatment may be as effective as treatment with clomiphene or unstimulated intrauterine insemination (IUI) in achieving a live birth, said Professor Siladitya Bhattacharya of the University of Aberdeen (Scotland) on behalf of the Scottish Unexplained Infertility Trial Collaborative Group.
“This really is the largest trial on the subject so far,” Dr. Bhattacharya said in an interview. The result “does not surprise me at all, because the effectiveness of some treatments is based on tradition rather than empirical evidence,” he added.
The study evaluated couples at five centers in Scotland who had experienced infertility for at least 2 years and who had confirmed ovulation, patent fallopian tubes, and motile sperm. Most participants in the study had primary infertility. The three randomized groups included 193 women in the expectant management group, 194 women who received 50 mg clomiphene on days 2–6 of a cycle, and 193 women who underwent unstimulated IUI over a period of 6 months. Patients in the treatment arms received up to six cycles of treatment.
Median female age, median body mass index, duration of infertility, and percentage with primary infertility were all similar among the different groups. No significant difference in sperm concentration or sperm motility was seen among the groups.
Based on available follow-up data at 16 months, the rate of live births was similar in the three groups. Thirty-three (17%) of the women in the expectant management group, 26 (14%) in the clomiphene group, and 43 (23%) in the IUI group achieved a live birth. Although significantly more women achieved a live birth in the IUI group, compared with the clomiphene group, neither active treatment was superior when compared with expectant management.
Dr. Bhattacharya said that providers tend to ignore the chance of a spontaneous pregnancy occurring in a general population of couples seeking infertility treatment. “This study highlights the potential for spontaneous pregnancy,” he said.
Some women probably do benefit from in vitro fertilization (IVF). “[For] those who have tried for a reasonable time and in whom age is an issue, we should think about IVF sooner,” he said.