What is Infertility
Infertility is more common than previously thought and occurs in approximately 10 to 15 percent of couples at some time during their reproductive lives. Infertility is defined as the inability to conceive after one year of unprotected intercourse; however, women over age 35 are advised to start infertility evaluation after six months of unprotected intercourse so as not to delay treatment.
A complex series of biologic events must occur for pregnancy to result.
- The ovary must contain eggs that will develop to maturity within the ovarian follicles under the influence of follicle stimulating hormone (FSH)
- The egg must be released (ovulated) from the follicle and travel through an open fallopian tube to the end near the uterus where fertilization occurs.
- The male must produce enough sperm to cause fertilization. A significant number of these sperm must be “normal” as determined by their shape, swimming ability, and several other characteristics.
- The sperm must travel through the vas deferens and urethra and be ejaculated into the vagina.
- Once deposited, the sperm must swim thorough the cervical mucus into the uterus.
- Once the sperm reaches the egg it must attach to and penetrate the outer membrane (zona pellucida). The DNA of the male and female must combine to produce a full complement of chromosomes.
- After the egg is fertilized, it divides to become an embryo. The embryo must travel into the uterus where it implants in the endometrial lining.
- Once the embryo implants its nourishment and development are supported by progesterone and other hormones.
- The uterus must be capable of supporting the growing fetus.
When one or more of these processes are impaired, infertility can result.
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