Unexplained Infertility

We define as infertility the unsuccessful attempt for a couple to achieve a natural conception after 18 months of active and frequent intercourse in the fertile phase of the female menstrual cycle.

After assessing the couple for infertility, some of the following causes are usually diagnosed:

  • Ovulation disorders and hormonal disorders of the menstrual cycle
  • Disorders of sperm parameters
  • Fallopian tube patency disorders
  • Endometriosis
  • Immune system disorders
  • Cervical parameters
  • Endometrial adhesions after microsurgery


However, 30% of the couples who visit a specialist gynaecologist to assess fertility have been diagnosed with “unexplained infertility”. Unexplained infertility is the infertility that is idiopathic which means that the original cause remains unknown after the primary investigations from a fertility specialist. The initial assessment of the gynaecologist is usually focused on the confirmation of the three basic parameters necessary in the context of physical conception. It includes the confirmed diagnosis of at least one patent fallopian tube, the woman’s physical and rhythmic ovulation and the normal parameters of the sperm (volume, count, motility, morphology).


Dealing with Unexplained Infertility

In dealing with unexplained infertility, the couple is encouraged to adapt to a healthier lifestyle modifying their diet to a low hypoglycaemic index meals and avoiding alcohol, tobacco and pre-made meals and having regular daily exercise.

The initial treatment protocols suggested worldwide are targeting on the increase of the number of mature eggs released each month (superovulation) and the synchronization of the exact time of the ovulation with the intrauterine insemination.

The American Society of Reproductive Medicine (ASRM) suggests that oral administration of drugs, such as clomiphene citrate and aromatase inhibitors (i.e. letrozole) may lead to the selection of more than one dominant follicles that can release mature oocytes with the enhancement of exogenous chorionic gonadotropin alfa. Increased number of released oocytes (< three oocytes) can subsequently increase the possibility one of them to be fertilized without the risk of ovarian hyperstimulation and with the best pregnancy rates among existing similar treatments.

The administration of injectable gonadotropins in low doses alone or in combination with the above medicines is also another treatment option, which, however, does not increase pregnancy rates compared to non-injectable protocols.

Intrauterine insemination or synchronized sexual intercourse of the couple following ovulation is usually not repeated for more than four cycles, as IVF remains the most successful option which can reveal underlying factors of infertility. Intrauterine insemination is a non-invasive method that is well-tolerated by women, but clinically it cannot provide us with useful information on cellular basis (gametes, fertilisation, embryos).


In vitro fertilization in Unexplained Infertility

In vitro fertilization also serves as a diagnostic method in which the causes of unexplained infertility can be identified. During IVF we can assess:

  • The woman’s menstrual cycle

    • The hormonal levels related with the number of ovarian follicles

    • The quality of the oocytes

    • The quality of the sperm

    • The rate of fertilization of the mature oocytes

    • The quality of the produced and developed embryos

In vitro fertilization is can be a therapeutic method with the best success rates in the case of unexplained infertility, but it is mainly a diagnostic tool, as it provides all the necessary information for gametes and formed embryos at the micro-molecular level.