Process of Conception

Hormonal Changes

During a woman's menstrual cycle, her body produces hormones to signal her ovaries to produce and develop an egg. The complete process of egg development and maturation takes about 2 weeks. During this time, the woman's hormones are also changing her cervical mucus to make it more welcoming to sperm. Hormones are also causing her uterine lining to grow thicker in anticipation of a pregnancy. When the egg is mature it is released into the woman's fallopian tubes in a process called ovulation. A mature egg remains viable for about 24 hours. The place on the ovary from which the egg was released is called the corpus luteum.

Fertilization

Sperm are present in the semen of a fertile man and are usually deposited in the female vagina by sexual intercourse culminating in ejaculation. The sperm then begin to swim into the woman's cervix, uterus and fallopian tubes in search of a mature egg. Fertilization occurs when a sperm penetrates the egg. Fertilization usually takes place in the fallopian tubes. Immediately after a sperm penetrates the egg, it seals itself off and begins the process of cell division and development.

Implantation

The fertilized egg continues its travel through the fallopian tubes to the woman's uterus. The fertilized egg implants itself into the uterine lining and begins to grow and develop. The fertilized egg develops chorionic villi, which produce human chorionic gonadotropin or hCG. HCG signals the corpus luteum to produce hormones to sustain the pregnancy until the placenta is fully functional. A pregnancy test looks for the presence of hCG in the woman's blood or urine to confirm pregnancy. A positive pregnancy test indicates successful conception.