Reproductive Health: Comparing Methods and Technologies: Quick Revision

A brief note on Reproductive Health: Comparing Methods and Technologies. Read it before a test. Try each question at the end before you open its answer.

Comparing the methods

• Protects against STIs: the condom only, among the methods of this chapter.
• Used by the female only: diaphragm, cap, vault, IUD, pills, injectables and implants, tubectomy.
• Used by the male: the male condom, withdrawal, vasectomy. Couple: periodic abstinence.
• Terminal: vasectomy and tubectomy. Reversal is very poor.
• Failure rates (not in the NEET text): the chance in one year grows over the years as $1 - (1 - f)^t$.

The pill and the cycle

• Natural cycle: FSH grows a follicle, estrogen rises, an LH surge near day 14 causes ovulation, progesterone follows.
• The pills: keep FSH and LH low, so there is no LH surge and no ovulation. They also stop implantation and change the cervical mucus.
• Schedule: 21 days with a pill, then a gap of 7 days with a bleeding.
• Saheli: non-steroidal, once a week. Emergency: within 72 hours of coitus.

Assisted techniques

• Gametes meet in a dish: IVF with ZIFT or the transfer into the uterus, and ICSI.
• Gametes meet in the body: GIFT, AI and IUI.
• Sites: up to 8 blastomeres into the fallopian tube, more than 8 into the uterus. The ovum of a donor in GIFT goes into the tube.
• Not in the NEET text: ICSI, AI, IUI and the arithmetic of chances.

A worked example

Two embryos are transferred, and each has a chance of $\dfrac{1}{2}$, on its own. What is the chance that at least one implants?

1. The chance that neither implants is $\dfrac{1}{2} \times \dfrac{1}{2} = \dfrac{1}{4}$.
2. At least one: $1 - \dfrac{1}{4} = \dfrac{3}{4}$.

Practice with new numbers

A program to try

The program lists the methods and picks out the one that also protects against infection.

Mistakes to avoid

• Saying that the pill protects against HIV. It does not. Only the condom does.
• Mixing up ZIFT and GIFT. ZIFT places a zygote or an early embryo. GIFT places an ovum.
• Saying that the pill stops ovulation by damaging the ovary. It keeps FSH and LH low.
• Putting an embryo of 16 cells in the fallopian tube. It goes into the uterus.

Check yourself

1. Which hormone surge is missing in a woman on the pill?

2. Which method protects against infection?

3. Where do the gametes meet in GIFT?

4. Which methods are terminal?

Sources

• NCERT (2023). Biology, Textbook for Class XII, chapters 2 and 3.
• World Health Organization and Johns Hopkins Bloomberg School of Public Health (2018). Family Planning: A Global Handbook for Providers, 3rd edition.