Name four human contraceptive techniques.

The different methods of contraception available are Natural/Traditional methods, Barriers, (Intrauterine Devices), Oral contraceptives, Implants, Injectables, and surgical methods.

Natural method-
- Periodic abstinence- In this method, the couples are advised to avoid coitus from the 10 th to 17 th day of the menstrual cycle when there is a high risk of ovulation.
Withdrawal or coitus interruptus- It refers to the withdrawal of the penis from the vagina just before ejaculation to avoid insemination.
Lactational amenorrhea- It is a natural phenomenon. It can be described as the absence of a menstrual cycle during the initial lactation phase after parturition.

Barrier method

It is based on the principle of avoiding the physical meeting of the sperm and ovum.

For example- Condoms are made up of rubber or latex and can be inserted into the vagina or penis. Other barriers to preventing conception are Diaphragms, cervical caps, and vaults. I U D s - They are inserted into the uterus through the vagina and need expertise.
Non-medicated IUDs- They are inert and are made up of either plastic or steel-for example, the Lippes loop.
Copper-releasing IUDs- They release copper ions in the uterine cavity, which increase the phagocytosis of sperms, and decrease sperm motility and its fertilising capacity. Examples CuT, Cu7, Multiload-375, etc.
Hormone-releasing IUDs- They release certain hormones that render the uterus unsuitable for implantation and thicken the cervical mucus plug so that sperm entry is blocked-examples Progestasert, L N G-20, etc.

Oral contraceptives-
These are available as 'pills' consisting of progesterone or a combination of oestrogen and progesterone. The hormones send negative feedback to the hypothalamus and pituitary glands and thus inhibit ovulation and implantation and alter the thickness of the cervical mucus plug. Implants and Injectables-
They are hormone-containing drugs that can be implanted or injected under the skin. The mechanism of action is the same as that of pills.
Surgical method-
It involves sterilisation techniques like Vasectomy and Tubectomy.