Unexplained Infertility

ByRobert W. Rebar, MD, Western Michigan University Homer Stryker M.D. School of Medicine
Reviewed/Revised Feb 2024
VIEW PROFESSIONAL VERSION

Unexplained infertility is diagnosed when sperm in the male partner is normal and when eggs, ovulation, fallopian tubes, and the uterus are normal in the female partner.

(See also Overview of Infertility.)

Treatment of Unexplained Infertility

  • Controlled ovarian stimulation

  • Sometimes assisted reproductive technologies

When no explanation for infertility is identified, an approach called controlled ovarian stimulation may be used.

Controlled ovarian stimulation may make pregnancy more likely and may help women become pregnant more quickly. This treatment may result in more than 1 fetus.

Controlled ovarian stimulation involves the following:

  • Women are given a fertility medication (), which stimulates several eggs to mature and be released, and human chorionic gonadotropin (hCG), which stimulates ovulation, for up to three menstrual cycles.

  • Semen is placed directly in the uterus to bypass the mucus (intrauterine insemination) within 2 days after treatment with hCG.

If pregnancy does not result after this treatment, one of the following may be done:

  • Another method of controlled ovarian stimulation, which involves giving women human gonadotropins (preparations containing hormones that stimulate the follicles of the ovaries to mature), followed by hCG to stimulate ovulation, then intrauterine insemination

Because multifetal pregnancy is a risk, clinicians often proceed directly to in vitro fertilization and avoid controlled ovarian stimulation.

Prognosis for Unexplained Infertility

clomiphene is immediately followed by in vitro fertilization. Thus, if clomiphene plus intrauterine insemination is unsuccessful, the next step is often in vitro fertilization.

Some evidence suggests that women who are over age 38 and have unexplained infertility conceive more quickly when in vitro fertilization is done rather than proceeding to controlled ovarian stimulation.

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