Human Reproduction

Conception

As the egg, or ovum, progresses through the fallopian tube toward the uterus, it secretes a special substance that acts as "runway lights" to guide any sperm which may have been released by a man during sexual intercourse. Millions of sperm are ejected by the man, and these are needed to break down the tough coating surrounding the egg cell. Once this occurs, only one sperm penetrates the egg, leading to pregnancy. This process, called conception or fertilization, is the point at which a new human life is formed. The developing embryo, or unborn child, is given its own unique set of DNA — half from the mother and half from the father. The DNA is like a blueprint that pre-determines the child's physical characteristics and many other traits as well. The embryo will then travel down to the uterus where it implants in the uterine lining and begins to grow. At the moment of implantation, a woman is officially considered pregnant in medical terms, although the embryo is very much alive before this point.

What is a Contraceptive?

At one time the term conception universally referred to the moment of fertilization. However, this has changed and now many important medical organizations use the word conception to mean implantation. The word contraceptive is used to refer to any birth control method that prevents fertilization or implantation as its primary mechanism. Barrier methods for women, condoms, and natrual methods prevent fertilization. Hormonal methods and the IUD work by both preventing fertilization and preventing implantation.

Although a woman is only fertile for a few days out of each menstrual cycle, unless she is monitoring her body it is hard to know exactly when she can conceive. If she wishes to avoid pregnancy she must either refrain from intercourse while she is fertile or employ the use of contraceptives, the most popular of which are described at this web site.

When Can I Get Pregnant?

Every woman's cycle is different, but with a little close attention you can determine what your cycle is like and when you can conceive. Conception is most likely to occur if you have intercourse near the time of ovulation. For women with regular cycles, ovulation is expected to occur about fourteen days before the onset of menstruation. But it is possible to ovulate anywhere from twelve to eighteen days before menstruation, depending on the woman. Practicing natural family planning, is an excellent way to determine your fertility patterns.

Sperm can survive for several days inside of a woman, residing safely in the fallopian tubes or in one of over a hundred gland-like cervical crypts. Although most sperm die within three days, they have been known to survive for as long as a week under certain conditions. Once released, an egg is viable for twenty-four hours. The fertile period is from several days before, to one day after, ovulation. It is important to remember, however, that your fertile period may not occur at the same time each month.

Featured Links

• The following links are at the Epigee site or are recommended:
  • Why is My Period Late?: Common reasons for menstrual cycle distrubances
  • Infertility and Fertility: How to get pregnant
  • Landmarks of Development of the Unborn Child
  
  
• The following links are provided as an informational resource or counterpoint and are not necessarily endorsed by the author:
  • How the Brain Organizes Sexual Behavior: From Brain & Mind, the Electronic Magazine of Neuroscience
  • When Does Life Begin?

Go to next section
[spermicides]