Definition

Understanding Conception

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Pregnancy begins when a woman’s egg and a man’s sperm join. This is called conception or fertilization.

Gender words are used here to talk about anatomy and health risk. Please use this information in a way that works best for you and your provider as you talk about your care.


The woman’s role in conception

Each month, one of a woman’s ovaries releases a mature egg (ovulation). The egg travels to the fallopian tube. If sperm are present, one of them may join with the egg to form an embryo. The embryo then travels to the uterus. There, it implants in the uterine lining, where it grows to become a baby. If conception doesn’t occur, the egg and the uterine lining are shed during your period (menstruation). A new cycle begins.

Front view of woman's pelvis showing cross section of uterus, ovaries, cervix, vagina, and fallopian tubes. Embryo is implanted in wall of uterus.


The man’s role in conception

Sperm are made in a man’s testicles. Fluid made by the prostate gland combines with sperm to form semen. During a man’s orgasm, semen flows to the urethra and out of the penis (ejaculation). If the semen was ejaculated in or near a woman’s vagina, sperm may travel into the uterus and the fallopian tubes. There, a sperm may join a mature egg to form an embryo. This results in pregnancy.

Side view of male reproductive anatomy with erect penis showing path of sperm.

© 2000-2026 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

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