The fallopian tubes are one of the main components of the female reproductive system, and they must work properly to ensure fertility. Each side of the uterus has a fallopian tube extending from it that reaches to the ovary on the corresponding side. The main function of the fallopian tubes is to catch eggs released from the ovaries each month during ovulation, and guide them into the uterus.
One ovary releases an egg each month in a healthy, ovulating female. Once the egg emerges from the ovary, small hair-like fibers on the ends of the fallopian tubes pull the egg inside the tube. The insides of the tubes are also lined with these small fibers, and they move and vibrate quickly to pull the egg up through the tube toward the uterus. The fallopian tubes keep the egg healthy while it waits for fertilization. Cells inside the lining of the tubes help keep the egg moving and provide it with nutrients until it is fertilized and reaches the uterus.
An egg stays inside the fallopian tube for 24 to 36 hours. During this time, fertilization is possible if sperm meets the egg. Once an egg has been fertilized, the tubes move the egg to the uterus, or womb, so that it can implant itself in the uterine lining. The tube contracts to help move the egg, a process that can take up to a week.
If the egg is not fertilized within 24 to 36 hours, it dies and disintegrates within the tube. Though a woman is only fertile for a day or a little longer after she ovulates, sperm can live inside the fallopian tubes for several days. This makes it possible for an egg to be fertilized from sperm that was present before ovulation.
Some women experience medical problems that interfere with the function of the fallopian tubes and other parts of the reproductive system. The tubes may be damaged because of a pelvic infection, uterine fibroids, or an ectopic pregnancy that occurs in a fallopian tube instead of in the uterus. If the tubes are blocked due to damage, an egg may not be able to move through them to the uterus, causing fertility problems. Surgery can often correct these problems, but the full function may not be restored. Women who undergo surgery on the fallopian tubes have a higher risk of ectopic pregnancies, and they may opt for in vitro fertilization to minimize this risk.