Fertility Infertility Issues

Couples who cannot conceive may turn to IVF (in vitro fertilization) to assist their chances of having a baby. IVF, however, is not always successful. Around 85% of embryos introduced to the uterus fail to implant, which means that most women require multiple cycles of IVF, usually with more than one enbryo per cycle introduced, in order to conceive.

For many couples who were hoping IVF would be their miracle, it can be devastating to go through cycle after cycle without a pregnancy developing. In fact, many couples never find out why IVF failed, leaving them wondering if they should spend the considerable amount of money it costs for IVF treatment to “gamble” on another cycle. Knowing the possible reasons for IVF failure may be helpful to couples wondering if they should try again, or look into other options.

Immunological problems

Although no study has shown a clear link between any elevated immune cell levels and IVF failure, many doctors feel that immune response may contribute to the failure of an embryo to implant. The body’s defense system would normally “sense” a growing fetus as an intruder, since its DNA is different from that of its mother. In a healthy pregnant women, immune response is muted to keep the mother’s system from attacking her own baby, but a women experiencing fertility problems and going through IVF may not experience that same dampening of the immune response. The theory is that the woman’s immune system is not letting the embryo implant into the wall of the uterus properly.

Time from harvest to implantation

Different doctors favor different waiting periods before introducing the embryos to the uterus. Some doctors will do the procedure three days after harvesting eggs and combining them with sperm, and some doctors will wait five. There is some evidence that “five day embryos” have a lower rate of implant failure. The theory is that embryos that look strong after three days might not actually be the strongest and most viable embryos to implant, and that by waiting five days, the doctor has a better idea of which embryos are actually more likely to thrive.

Endometriosis

Endometriosis, a condition seen in 5-10 percent of women during childbearing years, occurs when endometrial cells, normally only seen as part of the uterine lining, begin growing outside the uterus. Common places for these cells to grow are in the fallopian tubes and on the ovaries, although they may spread much farther. Women with endometriosis have a high rate of infertility, and of those who seek IVF treatment, there is a high rate of failure. The mechanism by which endometriosis might cause IVF failure is not currently clear.

Superovulation

For IVF treatment, a woman takes hormones to cause superovulation, which is the ripening of more than one egg during a cycle. Harvesting multiple eggs at once allows multiple embryos to be created, which is supposed to give a better choice of embryos likely to implant. However, there is a theory that perhaps the follicles in the ovary that would not have naturally produced a mature egg would not have done so for a reason: the egg in that follicle may have been inferior, or contained genetic abnormalities. It is currently a mystery why women produce four or more egg follicles a cycle and yet only one egg matures, but it could be because nature knows best, and the egg that matures is the one most likely to develop into a healthy embryo. If that is the case, harvesting eggs from other follicles may not increase the chance of successful pregnancy at all.

There are many different possible reasons for IVF failure, and a couple who has experienced it should have a long and thorough discussion with their doctor as to the possible reasons, and whether or not it is advised to continue with IVF treatment.