Conception Process

Ovulation

A woman's body must prepare for conception. It must nurture and release the egg that will become fertilized. The process by which a woman's ovaries release an egg is known as ovulation, and it marks the only time frame during the menstrual cycle when a woman can become pregnant. For many women, this process occurs around day 14, or in the middle her her menstrual cycle. According to the American Pregnancy association, each woman's body is different and cycle lengths vary. Some women have shorter cycles and some have longer, so ovulation doesn't necessarily occur at day 14 for some women. To find out if you are ovulating or fertile, calculate the middle of your menstrual cycle and use it as a time to begin looking for changes in your cervical mucous and body temperature. Cervical mucous is typically described as egg white in texture during your fertile time, meaning it's clear and stretchy rather than white or creamy. During this time your body temperature also raises by about one degree, which you can track using a basal thermometer and taking your temperature each morning. Because sperm can live in the body for three to five days, sex on the day before ovulation, the day of ovulation and the day after ovulation are most likely to result in a pregnancy. This is because sperm will wait out the egg if it hasn't yet been released.

Fertilization

The first step toward fertilization is depositing the sperm into the vagina. During heterosexual intercourse, the male ejaculates semen into the vagina. During insemination, a health care provider other individual uses a syringe or other medical device to deposit sperm into the vagina or uterus. Many gay and lesbian or infertile couples use insemination rather then intercourse to join egg with sperm. This sperm then begins swimming toward the egg.The sperm must travel through the vagina toward a small opening in the cervix, called the cervical oz. Once it passes through the oz, it is inside the uterus. Sometimes sperm cells meet the egg cell in the uterus, but more often, the sperm keeps swimming into the fallopian tube, where the egg is waiting. This egg must be fertilized within 12 to 24 hours, or it will dissolve. The first sperm to reach the egg uses chemical messengers on its head to signal to the egg to let it in. Once it's inside, more chemical signals prompt the egg to quickly shut out all other sperm, who will eventually die.

Implantation and Growth

The now-fertilized egg travels down the fallopian tube and toward the rich, nutritious lining of the uterus. This lining is normally shed during menstruation, but because fertilization has occurred, this lining will become the new nest for the egg. It's also the lining that your doctor will remove, should you decide to terminate your pregnancy. The egg travels toward this lining and burrows itself in. Some women experience spotting, or implantation bleeding when this happens, but many do not. The egg, which is rapidly dividing and growing, gets oxygen and nutrients from the uterine lining until the placenta develops. The placenta then serves as the nutritional link from the mother to the fetus.