New News Biology #43

Contraception

Main methods of contraception (any artificial methods people use to prevent pregnancy):

It has to somehow interrupt the process of an egg being stimulated to grow, then released, and lastly being fertilized by a sperm cell.

Hormonal methods:

If oestrogen is released everyday, it inhibits FSH, so no egg will be developed.

If progesterone is released, it stimulates a thick mucus at the cervix (entrance to the uterus) which prevents the sperm from ever reaching the egg.

The combined oral contracepive pill is 99% effective in preventing pregnancy, though can have side effects such as headache and nausea.

Progesterone-only methods:

There is also a progesterone-only pill which is also quite effective but with less side effects.

The contraceptive patch is a sticker that slowly releases the two hormones and usually lasts 1 week.

A contraceptive injection injects progesterone into the body and lasts 2-3 months.

The contraceptive implant is an implant of a small device under the skin of the arm, and slowly releases progesterone for up to 3 years.

There is also the plastic intrauterine device (IUD) which slowly releases progesterone and is located inside the uterus.

Another type of IUD is the copper version, which is not a hormonal method of contraception, but simply kills the sperm cells.

Both IUDs can last over 3 years.

Non-hormonal methods:

Condom (fits over the penis, and traps sperm inside) Female condoms (fits inside the vagina, does basically the same thing)

They also protect against sexually transmitted diseases.

Diaphragm (a plastic cup which fits over the cervix, blocks sperm from entering the uterus) usually is also used with spermicide (which kills sperm). Spermicide can also be used along as a form of contraception, but works only 7/10 times, so it is not very effective.

More permanent methods:

Sterilization (cutting the fallopian tubes in women) or (cutting the sperm ducts in men)