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Chapter 54 Infertility
Neely N. Nelson, MD
BASIC FACTS AND DEFINITIONS
❍ What is fecundability?
The probability of achieving a pregnancy within one menstrual cycle.
❍ What is fecundity?
The probability of achieving a live birth within one menstrual cycle.
❍ What is the average fecundability in normal couples?
20%.
❍ What are the causes of infertility for couples?
30% to 40% ovarian dysfunction.
30% to 40% tubal/peritoneal pathology.
30% to 40% male factor.
❍ When should a workup for infertility be initiated?
All couples after 1 year of regular intercourse without conception.
Couples not pregnant after 6 months of regular intercourse and the female partner is >35 years of age, has
endometriosis, or has irregular menses, or the male partner has known or suspected poor semen quality.
❍ How long do the egg and sperm have to fertilize in the female reproductive tract?
Oocytes have a 12- to 24-hour life span, and normal sperm have a 3- to 5-day life span.
❍ Does radiation therapy cause gonadal failure more commonly in males or females?
Males. Almost all males at any age will have testicular failure.
Females in early reproductive years treated with <700 rads usually do not have ovarian dysfunction. Greater than
2000 rads cause ovarian failure in most women. 15 rads is sufficient to suppress spermatogenesis.