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Reproductive Endo/Infertility
Missouri Center for Reproductive Medicine and Fertility
Unexplained Infertility

If no abnormalities are found following a complete infertility work-up, the couple is considered to have unexplained infertility. It is important to realize that in this situation, treatment is not geared to correct a problem, since none were found. Instead, treatment is geared towards accelerating the time to pregnancy. Couples are also reminded that they could still become pregnant at any time without treatment; however, we cannot predict if this would occur within 2 months, or if the couple would still not be pregnant 3 years later. Thus, most couples opt for treatment with this diagnosis.

There are two main principles of treatment, which must be applied together if success rates are to be optimized. Studies have indicated that using either one of these principles separately to treat unexplained infertility does not improve chances for conception.

1) Increase the number of eggs (using fertility shots or pills) - this is based on the fact that each egg would have an independent chance to be fertilized and subsequently produce a pregnancy. If more eggs are produced in one cycle, the chances for pregnancy in that individual cycle should be increased.

2) Place sperm and egg closer together (using IUI or IVF) - after ejaculation, millions of sperm are normally present in the vagina; however, much smaller numbers reach the egg. By placing more sperm in close proximity to more eggs (after using fertility drugs) the odds for conception in that cycle increase.

Monthly pregnancy rates for a normal couple trying to conceive is about 20-25%.The possible treatment options are listed below with generalized success rates in women < 35. Typically, a maximum of 3-4 cycles of a given treatment are recommended before moving to the next step, although couples have the option of moving to the next treatment step before completing the maximum number of cycles.

  1. Clomiphene Citrate (Fertility Pill) + IUI Pregnancy Rate/Cycle 15%
  2. Gonadotropins (Fertility Shots) + IUI Pregnancy Rate/Cycle 18-20%
  3. Gonadotropins (Fertility Shots) + IVF Pregnancy Rate/Egg Retrieval40-50%


Related Pages
Causes of Infertility
Infertility Evaluation
Ovulation Disorder and PCOS
Male Factor
Pelvic Factor
Unexplained Infertility
Tubal Reversal

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