Unexplained Infertility: How to Explain it?
Infertility is defined as inability to conceive after 12 months of regular unprotected intercourse. Once a couple is diagnosed with infertility, a series of tests are performed to find the underlying cause. These include testing of the female partner for ovulation, for patency of the fallopian tubes, and for “ovarian reserve,” which includes evaluation of the quantity of the eggs remaining in the ovaries. The male partner is evaluated with a semen analysis to ensure adequate number of swimming sperm with normal shape. If all these tests come back normal, which may happen in up to 30% of couples being evaluated for infertility, the couple is diagnosed with unexplained infertility. Although frustrating at first, this is not necessarily an ominous diagnosis, since empiric treatments, as I will briefly explain later in this blog, are often efficacious in achieving a successful pregnancy.
Once a couple is diagnosed with unexplained infertility, the first question they ask, and rightfully so, is “What does this mean?”. The answer is as simple as it is complex at the same time. Simply put, we don’t know why the couple is not achieving conception following the results of a basic evaluation. However, it is as complex an answer as complex is achieving a pregnancy. Let me explain.
In order to successfully establish a pregnancy, there should be enough sperm ejaculated in the vagina; these sperms, at least one of them, have to successfully swim through an open cervical canal to the uterus and eventually to the tubes where they have to find the egg. Simultaneously, ovulation should occur and the egg has to be captured by the fallopian tube and travel to the widest portion of the tube called the ampulla, where fertilization occurs. Once and if fertilization occurs, then the embryo has to continue to divide and grow, and be propelled to the uterus by the microscopic projections in the tubes. This journey takes about 4-5 days, at the end of which the embryo reaches the uterus. About day 5-6 after fertilization, the embryo has to attach to the lining of a receptive uterus while at the same time it has to continue to grow successfully.
As seen in these steps, there may be many hurdles to achieve a pregnancy: the sperm may be deposited in the vagina but may not be able to reach the fallopian tubes, due to a potentially unfavorable uterine environment; it may not find the egg; it may find but not penetrate the shell of the egg; it may penetrate the egg but fertilization may not occur; despite fertilization, the embryo may not divide or not continue to grow; the tiny projections on the inner surface of the tubes may be paralyzed and not propel the embryo back in the uterus; the embryo may grow and reach the cavity of the uterus but may not attach to the lining. The reason for the latter is that there should be certain proteins on the surface of both the embryo and the lining of the uterus so that they can recognize each other and attachment can occur. If any of these proteins is missing, then the embryo cannot attach to the lining.
So, as seen above, there are a lot of potential reasons for not achieving a successful conception despite everything being “normal.” At RMA of New York, we will discuss these potential reasons with you and come up with a treatment tailored to your situation. These treatments often involve artificial insemination and in vitro fertilization (IVF), or test tube baby. IVF, apart from being the most successful treatment in the shortest period of time, may also shed light into the cause of infertility. Since the fertilization is performed in the lab and early stages of the embryo development are directly visualized under the microscope, problems associated with fertilization and embryo growth and development, if there are any, often become readily apparent and we can tell the couple what the cause of infertility is. Moreover, if the embryos are tested and found to be abnormal genetically, this may give another explanation.
Being diagnosed with unexplained infertility is frustrating at first because it is in our nature to search for and find answers to conditions that affect us. However, again, the good news is that this is often a treatable condition and with advanced fertility treatments, not only a successful treatment can be achieved but sometimes we can find the answers we are looking for.