Unexplained Infertility

Common Fertility Problems
 
Key Points

  • Unexplained infertility happens in 15% to 30% of couples.
  • Expectant management with timed intercourse and lifestyle changes for 2 years is suitable when the woman’s age is less than 30.
  • IVF with ICSI is the treatment of choice when women are above 35 and other options have failed.

What is Unexplained Infertility?

Unexplained infertility happens when a couple has been trying to conceive for at least 1 year and a cause of infertility is not identified. Approximately 15% to 30% of couples are diagnosed with unexplained infertility after their basic fertility evaluation.
 

Diagnosis of Unexplained Infertility

The basic fertility evaluation includes:

  • Semen analysis (repeated after 1 month if abnormal)
  • Assessment of ovulation and luteal phase (progesterone, LH)
  • Assessment of tubal patency (hysterosalpingogram)
  • Assessment of ovarian reserve (AMH, AFC, FSH, E2)
  • Assessment of uterine cavity (ultrasound)
  • and if indicated, laparoscopy.




When the results of a standard infertility evaluation are normal, healthcare professionals assign a diagnosis of unexplained infertility.

The inability to find the causes of couples’ infertility does not mean that there is no cause for the disorder. Professionals must search for all possible causes of failed conception and consider ovarian and testicular dysfunctions, sperm and egg quality, fallopian transport problems, endometrial receptivity, implantation failures and endometriosis.

Treatment of Unexplained Infertility

The treatment for unexplained infertility is empirical because it does not address a specific defect or functional impairment. The guideline of National Institute for Health and Care Excellence (NICE) on fertility suggests some treatment options regarding management of unexplained infertility. The age of women and infertility duration are important factors in offering specific therapy to a couple.

  • Expectant management with timed intercourse and lifestyle changes for 2 years is the best choice for good prognosis when the woman's age is less than 30. This requires women to be aware of their ovulation time and the best period for unprotected intercourse. The chances of pregnancy with this approach are lower than couples without infertility, but higher than in couples with a defined cause of infertility.


  • Clomiphene citrate and intrauterine insemination (IUI) or Controlled ovarian hyperstimulation (COH) with IUI can be used to stimulate ovulation and place sperm in the uterus.
  • IVF is suitable for couples over 35 with long duration of infertility. In comparison with COH/IUI, IVF shortens time to pregnancy and reduces the risk of multiple pregnancies. Failed fertilization is reported in 8.4%-22.7% of IVF cycles for couples with unexplained infertility; therefore, many clinics offer routine ICSI for these couples. Several studies suggested IVF/ICSI would be the best option since its cumulative pregnancy rates are higher than conventional IVF. This is the treatment of choice for unexplained infertility when the less costly treatment approaches have failed.

The Small Book of Fertility Hormones

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