Unexplained Infertility

What is 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.

What is standard infertility testing?

T he definition of what “standard testing” consists of is not agreed upon by all experts. Medical studies have reported that 0-26% of infertile couples have unexplained infertility. The most commonly reported figures are between 10-20% of infertile couples. However, those percentages are from studies in which all the women had laparoscopy surgery to investigate the pelvic cavity for pelvic scarring and endometriosis. Laparoscopy surgery is no longer done as part of the routine fertility workup. Therefore, we are not finding all of the causes of infertility that we used to – leaving many more couples in the unexplained category.

  • The current rate of unexplained infertility is about 50% for couples with a female partner under age 35, and about 80% by age 40
  • In reality, there are probably hundreds of “causes” of infertility

There are a lot of things that have to happen perfectly in order to get pregnant and have a baby As an overly simplified example of the science involved:

  • The hormones that stimulate egg development must be made in the brain and pituitary and be released properly.
  • The egg must be of sufficient quality and be chromosomally normal
  • The egg must develop to maturity
  • The brain must release a sufficient surge of the LH hormone to stimulate final maturation of the egg
  • The follicle (eggs develop in structures called follicles in the ovaries) must rupture and release the follicular fluid and the egg
  • The tube must “pick up” the egg
  • The sperm must survive their brief visit in the vagina, enter the cervical mucous, swim to the fallopian tube and “find” the egg
  • The sperm must be able to get through the cumulus cells around the egg and bind the shell (zona pellucida) of the egg
  • The sperm must undergo a biochemical reaction and release their DNA package (23 chromosomes) into the egg
  • The fertilized egg must be able to divide
  • The early embryo must continue to divide and develop normally
  • After 3 days, the tube should have transported the embryo down into the uterus
  • The embryo must continue to develop and expand into a blastocyst
  • The blastocyst must hatch out of its shell
  • The endometrial lining of the uterus must be properly developed and receptive
  • The hatched blastocyst must attach to the endometrial lining and “implant”