By Dr. Dipesh Sorathiya, IVF Speciality,
According to PubMed, standard fertility evaluation will fail to identify the causes of infertility in 15-30% of the infertile couples. This state of infertility is called unexplained infertility. As per a study by the National Center for Health Statistics, the percentage of American women in the age group 15-44 having impaired fecundity is 12.3%. In absolute numbers, this corresponds to 7 million women. Though these numbers are from the US, this condition afflicts many women from other parts of the world.
Possible Reasons for unexplained infertility
- The egg is not released at the right time for fertilisation.
- The egg may not enter the fallopian tube.
- The sperm is not able to contact the egg.
- Fertilisation of the egg does not take place.
- The zygote transportation process may be affected unfavourably.
It is now being believed by many gynaecologists that for successful fertilisation, the egg quality needs to be of good quality. Many women in their advanced maternal age are unable to have normal fertilisation because of reduced egg quality.
Increasingly, researchers are admitting that the epigenetic changes in sperm may also cause unexplained infertility.
Prevalence of unexplained infertility
This phenomenon significantly increases in the cases of women above 35 and greatly increases if the women are above 38. As we have seen earlier, as women age, there is an increasing likelihood of the egg quantity and quality problems.
Most women who are above 40 will find it difficult getting pregnant. This problem increases when they cross 44 years. There is no guarantee that an ovulating woman who is above 44 will conceive. Her chances of conception are rare.
Treatment options for unexplained infertility
- In some cases, couples have overcome unexplained infertility through a combination of injectable shots of FSH hormone and intrauterine insemination(IUI).
- The combination of injectable gonadotrophins and sexual intercourse- In some case, unexplained infertility has been treated by this method. But it remains to be seen whether these IUI and ovarian stimulation through intercourse are effective in combination. Some studies suggest that intrauterine insemination is more effective when used independently.
- In Vitro Fertilization or IVF-Most couples facing unexplained infertility opt for IVF and the success rates improve if the female partner has normal ovarian reserve testing.Typically, most couples – the female partner is under 40 in such cases- will try for 3 artificial inseminations. If the woman fails to conceive after these three attempts, the couples go in for IVF.
IVF can also shed some light on causes of infertility like fertilisation rates per egg, slow embryo development etc.
Though the problem of unexplained infertility is significant, it is not that it cannot be treated. Many couples can conceive with the aid of IVF.