Q.Describe the various contraceptive methods.

Contraceptive methods prevent pregnancy through several different strategies - avoiding fertile-period intercourse, physically or chemically blocking sperm-egg contact, altering the uterine/hormonal environment, or permanently blocking the gamete pathway - and are chosen based on effectiveness, reversibility and user convenience.

Categories of contraceptive methods:

1. Natural/behavioural methods (no device or hormone used):

   • Periodic abstinence (rhythm/calendar method): couples avoid coitus during the estimated fertile period of the menstrual cycle, when the chance of fertilisation is highest.
   • Coitus interruptus (withdrawal): the penis is withdrawn from the vagina before ejaculation, preventing sperm from entering.
   • Lactational amenorrhea method: intense breastfeeding suppresses ovulation and provides natural, temporary infertility for up to about six months after childbirth.

2. Barrier methods: physically prevent sperm from reaching the egg.

   • Condoms (male and female): thin sheaths that also help prevent transmission of sexually transmitted infections.
   • Diaphragms, cervical caps and vaults: devices inserted into the vagina to cover the cervix, usually used together with a spermicidal cream or jelly for extra protection.

3. Chemical/spermicidal methods: creams, jellies and foams containing spermicidal agents that immobilise or kill sperm, generally used in combination with a barrier method.

4. Intra-uterine devices (IUDs): small devices inserted into the uterus by a trained provider.

   • Copper-releasing IUDs (e.g., CuT, Cu7): copper ions increase phagocytosis of sperm and make the uterine environment unfavourable for fertilisation and implantation.
   • Hormone-releasing IUDs (e.g., progestasert, LNG-20): slowly release a progestogen that thickens cervical mucus and thins the uterine lining. IUDs are popular for women wishing to delay or space pregnancies without daily intervention.

5. Hormonal methods: use synthetic estrogen and/or progestogen to prevent ovulation and alter the reproductive tract.

   • Oral contraceptive pills: combination pills (estrogen + progestogen) or progestogen-only pills, taken daily, mainly work by inhibiting ovulation and thickening cervical mucus.
   • Injectables and subdermal implants: long-acting hormone preparations administered every few weeks/months or implanted under the skin, offering convenience without daily dosing. …