Course 21.1Lesson 2 of 3

Natural, barrier and intrauterine methods

Natural methods use no device, but they fail often. Barrier methods keep the sperm and the ovum apart, and a condom also protects against infection. An intrauterine device is placed in the uterus by a trained person, and it stops fertilisation for years.

about 30 min1 simulation1 practice question

Lesson 2 of 3Show all lessons

Try the code and the simulations beside the lesson.

What a good method looks like

A contraceptive is a method that prevents pregnancy. NCERT lists what an ideal contraceptive should be.

User-friendly and easily available.
Effective and reversible.
With no side effects, or as few as possible.
Not interfering with the sexual drive, desire or act of the user.

No single method is perfect on every point. This is why there are many methods. They fall into seven groups.

A tree chart. A box at the top says Methods of birth control, with six arrows down to six boxes. Natural: periodic abstinence, withdrawal, lactational amenorrhea. Barrier: condom for the male and female, diaphragm, cervical cap, vault, and spermicides. IUDs: non-medicated (Lippes loop), copper releasing, hormone releasing. Oral pills: progestogen alone or with estrogen, and Saheli taken once a week. Injectables and implants: progestogen alone or with estrogen, long acting. Surgical: vasectomy for the male and tubectomy for the female. A line at the bottom says that a condom is the only method of this chapter that also protects against infections.

This lesson covers the first three groups. The next lesson covers the rest. Nothing here is advice for a person. A qualified doctor is the right person to ask.

Natural methods

Natural methods use no medicine and no device, so they have almost no side effects. Their chance of failure is high.

Periodic abstinence. The couple avoids coitus from day 10 to day 17 of the menstrual cycle. Ovulation is expected in this time, and the chance of fertilisation is very high. So it is called the fertile period.
Withdrawal, or coitus interruptus. The male partner withdraws the penis from the vagina just before ejaculation, so that there is no insemination.
Lactational amenorrhea. In the first months after a baby is born, a mother who breast-feeds fully does not ovulate and has no menstrual cycle. So the chance of conception is almost nil. NCERT says that this holds only up to six months after the birth.

A row of 28 numbered squares, one for each day of a cycle of 28 days, with day 1 as the first day of bleeding. Days 1 to 5 are shaded red and marked as bleeding. Days 10 to 17 are shaded yellow and marked as the days of abstinence, the fertile period. Day 14 has a red border, and an arrow from below marks it as ovulation. Days 18 to 28 are marked as after the fertile period.

Why does periodic abstinence fail so often? The days 10 to 17 belong to a cycle of 28 days. Not every person has a cycle of that length. A cycle can also change from month to month. Then ovulation comes on another day, and the days that the couple leaves out are the wrong days.

You should find that the model matches the days 10 to 17 only for a cycle of 28 days. In a cycle of 24 days, four fertile days fall before day 10.

Barrier methods

A barrier method keeps the ovum and the sperms from meeting.

Condoms are thin sheaths of rubber (latex). The male condom covers the penis, and the female condom covers the vagina and the cervix. They are used just before coitus, so that the semen does not enter the female reproductive tract. Nirodh is a popular brand of condom for the male in India. Condoms are used once. They can be put on by the user, and this gives privacy.
Diaphragms, cervical caps and vaults are rubber devices that are placed in the female reproductive tract to cover the cervix during coitus. They block the entry of sperms into the cervix. They can be used again.
Spermicidal creams, jellies and foams kill sperms. They are used together with diaphragms, caps and vaults, to make them more effective.

Four simple drawings of barrier devices in a row, in light blue. The condom for the male is a sheath that covers a cylinder, and is labelled as covering the penis before coitus. The diaphragm is a large rubber dome with a rim that covers the cervix. The cervical cap is a small cup that fits over the cervix. The vault is a wider, shallow cup in the top of the vagina. A line at the bottom says that the diaphragm, cap and vault are reusable, and that condoms are used once.

Condoms have a second benefit: they protect against sexually transmitted infections (STIs), including HIV/AIDS. This is why their use has increased.

Intrauterine devices (IUDs)

An intrauterine device is a small device that a doctor or a trained nurse places in the uterus through the vagina. There are three kinds.

Kind	Examples
Non-medicated	Lippes loop
Copper releasing	CuT, Cu7, Multiload 375
Hormone releasing	Progestasert, LNG-20

How do they work?

An IUD makes the cells of the uterus engulf sperms in large numbers. This is phagocytosis.
The copper ions from a copper releasing IUD reduce the movement of the sperms and their power to fertilise an ovum.
A hormone releasing IUD does more. It makes the uterus unsuitable for the embedding of an embryo (implantation), and it makes the cervix hostile to sperms.

IUDs are ideal for women who want to delay a pregnancy or to leave a gap between children. They are among the most widely accepted methods in India.

A front view of the female reproductive tract: the uterus in the middle, a fallopian tube rising from each upper corner to an ovary, the cervix at the narrow lower end of the uterus, and the vagina below. A T-shaped copper releasing device, the CuT, with copper wire wound on its stem and arms, sits inside the cavity of the uterus, with a thread that hangs down into the vagina. Labels name the uterus, the ovary, the cervix, the vagina and the device. A note says that copper ions make sperms move less and fertilise less well.

Try it in Python

The program uses the model of the fertile period for cycles of different lengths. It counts the fertile days that fall outside days 10 to 17.

Practise with new numbers

Common mistakes

Saying that periodic abstinence is always safe. It has a high chance of failure, because the day of ovulation changes.
Saying that a condom is used again. Condoms are used once. Diaphragms, caps and vaults are reusable.
Mixing up the copper IUD and the hormone releasing IUD. Copper ions affect the sperms. The hormone releasing kind also changes the uterus and the cervix.
Saying that lactational amenorrhea works for as long as the baby is fed. It works only up to six months, and only with full breast-feeding.
Saying that every method protects against STIs. Among these methods, the condom is the one that does.

Remember these

An ideal contraceptive is user-friendly, available, effective, reversible and with few side effects.
Natural methods: periodic abstinence (days 10 to 17), withdrawal, lactational amenorrhea (up to six months).
Barrier methods: condoms, diaphragms, cervical caps, vaults, with spermicides. Condoms also protect against STIs.
IUDs: Lippes loop (non-medicated), CuT, Cu7 and Multiload 375 (copper), Progestasert and LNG-20 (hormone).
Copper ions reduce sperm movement and power to fertilise. Hormone releasing IUDs also block implantation and make the cervix hostile.

Check yourself

Try each one on your own first. If you are stuck, open a hint. Then check with Show the answer.

Name the three natural methods of birth control.

Which days are the fertile period in a cycle of 28 days, according to NCERT?

Why is a condom useful in more than one way?

How does a copper releasing IUD stop a pregnancy?

Name one example each of a non-medicated, a copper releasing and a hormone releasing IUD.

References

NCERT (2023). Biology, Textbook for Class XII, chapter 3, Reproductive Health.
World Health Organization and Johns Hopkins Bloomberg School of Public Health (2018). Family Planning: A Global Handbook for Providers, 3rd edition, chapters on condoms, diaphragms and IUDs.