Health Conditions

What causes it?

Although preventing pregnancy is usually not considered to be a health condition, hormonal contraceptives do represent one of the few drug classes that are widely used by healthy individuals.

How Does Hormonal Contraception Work?

Hormonal contraception upsets normal female hormonal cycles in the human body. Generally, additional amounts of one or two female hormones are used to disrupt the balance of hormones that is needed for pregnancy to occur.

Estrogens:

• prevent ovulation (the release of eggs from the ovaries)
• affect the time needed for an egg to travel through the fallopian tubes, thus interfering with precise timing needed for fertilization
• interfere with the implantation of a fertilized egg on the wall of the uterus

Progestins:

• prevent ovulation (the release of eggs from the ovaries)
• affect the time needed for an egg to travel through the fallopian tubes, thus interfering with precise timing needed for fertilization
• increase the amount and thickness of mucus at the cervix (the opening of the uterus), thereby decreasing sperm entry to and passage through the vagina
• decrease the ability of sperm to fertilize an egg
• interfere with the implantation of a fertilized egg on the wall of the uterus

For a more detailed description of the menstrual cycle, click on the link below.

• The Menstrual Cycle