Infertility is defined as the inability to conceive after one year of sexual intercourse without the use of any contraceptive methods. It is not always possible to determine if the eggs are actually released from the follicles, if the fallopian tubes are patent or if the sperm is capable of reaching and fertilizing the egg. Unexplained infertility affects up to 25% of infertile couples. In vitro fertilization (IVF) is an appropriate treatment for unexplained infertility.
Infertility cases in which the standard infertility testing has not found a cause for the failure to get pregnant. Unexplained infertility is also referred to as idiopathic infertility. Another way to explain it is the “doctors can’t figure it out” group. In approximately 15% of all infertility cases, the cause remains unknown after a thorough examination and testing of both the male and the female. In some cases, a comprehensive review of all testing and treatment previously performed reveals clues in a past evaluation that may help lead to a diagnosis. Your physician may also request that your partner repeat a semen analysis for a more recent specimen and that you undergo a hysterosalpingogram (HSG) to confirm that there is no scarring or abnormalities in the uterine cavity. If risk factors suggest tubal disease, a laparoscopy may be performed to treat endometriosis and rule out pelvic scarring.
Unexplained Infertility may be a misnomer since it assumes that in most cases we do not know what is the cause of infertility. In fact there is often something wrong at a more basic level. For example, it is possible that there is something wrong at the level of the gametes (egg & sperm), their interaction with each other, or their interaction with the female reproductive organs.
It is also possible to have sperm that appear normal under a microscope, however not perform the function of fertilization adequately. Furthermore, one can have normal sperm but poor quality eggs that do not fertilize or fertilize at a lower than expected rate. If normal eggs and sperm meet, one can expect a fertilization rate between 60 to 90 percent. The outer shell of the egg, the Zona Pellucida, usually hardens after one sperm enters the egg. It is possible for the outer shell not to allow a sperm to enter, or allow too many sperm to enter the egg. Both these situations result in abnormalities that lead to infertility.
Once an egg is fertilized, there is an 80 percent chance of cell division. The rate of division of the resulting embryo is also of significance. Usually 48 hours after fertilization, the embryo is between two to four cells (blastomeres). At 72 hours, they are usually between six to eight cells. After five days of growth, they are usually over 120 cells with a fluid cavity in the middle (Blastocyst). If a larger than expected percentage of embryos divide slowly or stop dividing at any stage, this can result in infertility.
Causes of unexplained Infertility
• Abnormal Fallopian tubes
• Abnormal eggs
• Abnormal Luteal Phase
• Immune Problems
• Weak Sperm
• Psychological Factors