Family Planning Methods — Spacing vs Terminal, Pearl Index, IUCDs, Antara, Chhaya and Emergency Contraception

India's national programme sorts contraceptives by what the couple wants next. MoHFW states that the methods 'can be broadly divided into two categories, spacing methods and permanent methods', with the emergency contraceptive pill as an additional method for emergencies. Spacing methods are reversible and meant for couples who still want children; permanent (terminal, limiting) methods are for couples who have completed their family.

Textbooks also group methods by mechanism: barrier (condom, diaphragm, spermicide), hormonal (pills, injectables, implants), intrauterine devices, natural or fertility-awareness methods (LAM, calendar, withdrawal) and surgical methods. Both schemes appear in questions — read whether the stem asks about the type of method or its programme role.

The Pearl Index expresses contraceptive failure as the number of unintended pregnancies per 100 woman-years of exposure. Trussell describes it as 'obtained by dividing the number of unintended pregnancies by the number of years of exposure to the risk of unintended pregnancy contributed by all women in the study'. When exposure is counted in months, multiplying by 1,200 (12 months × 100 women) gives the rate per 100 woman-years.

Worked example: 100 women use a method for 12 months each (1,200 woman-months) and 3 become pregnant. Pearl Index = 3 × 1,200 ÷ 1,200 = 3 per 100 woman-years.

Perfect use is the failure rate when a method is used consistently and exactly as directed; typical use is what happens in real life, including missed pills, late injections and forgotten condoms. The gap is widest for methods that depend on the user at every act of intercourse or every day, and almost nil for methods that are 'fit and forget'.

The Lippes loop entered India's programme in 1965, Copper T 200B in 1975, Cu IUCD 380A in 2002 (replacing CuT 200B) and Cu IUCD 375 in 2012, so that women could choose between a 10-year and a 5-year device.

• Mechanism: copper ions reduce sperm motility and function, so sperm do not reach the tube to fertilise the egg; the device also provokes a foreign-body reaction in the endometrium that hinders implantation.
• Effective immediately after insertion; usable as emergency contraception if inserted within 5 days of unprotected intercourse.
• Follow-up at 1, 3 and 6 months, because expulsion is highest in this period.
• The expiry date on the pack refers to sterility of the packet, not contraceptive life — a device inserted the day before expiry still works for its full 10 or 5 years.

Antara is the programme name for injectable depot medroxyprogesterone acetate (DMPA, MPA), a progestogen-only injectable. One dose is a vial of 150 mg, given deep intramuscularly into the deltoid, the upper outer gluteal region or the outer thigh, every three months.

• Grace period: the repeat dose can be given up to 2 weeks early or 4 weeks late without a backup method.
• Breastfeeding: suitable from 6 weeks post-partum; it does not affect the quantity or quality of milk.
• Side effects: irregular or prolonged bleeding and amenorrhoea, weight change, headache, mood change and a decrease in bone mass.
• Return of fertility is delayed — about 7–10 months from the last injection (on average 4–6 months after the 3-month effect ends).
• A lower-dose subcutaneous MPA (104 mg/0.65 mL) is registered in India and is therapeutically equivalent to the IM form.

Centchroman (ormeloxifene) was developed indigenously at the Central Drug Research Institute (CDRI), Lucknow, and was added to the programme as Chhaya in April 2016. It is a non-steroidal, non-hormonal pill that acts as a selective oestrogen receptor modulator (SERM) — weakly oestrogenic in some tissues such as bone and strongly anti-oestrogenic in the uterus and breast.

1. First 3 months: one 30 mg pill twice a week — the first on day 1 of the period and the second 3 days later, on the same two weekdays thereafter.
2. From the 4th month: once a week, on the first pill day, regardless of the menstrual cycle.
3. Missed pill: take it as soon as remembered; if more than 7 days late, restart as a new user (twice weekly for 3 months).

It does not stop ovulation; it acts mainly by making the endometrium unreceptive and disturbing the timing of embryo transport, so implantation fails. It is safe during breastfeeding. Its main effect on the cycle is prolongation of the cycle with lighter periods, which MoHFW describes as helpful for anaemic women; if a period is delayed by more than 15 days, pregnancy must be excluded.

Emergency contraception is used after unprotected intercourse, contraceptive failure (such as a burst condom or missed pills) or coerced sex. It is not an abortifacient: WHO states that emergency pills 'prevent pregnancy by preventing or delaying ovulation and they do not induce an abortion'.

The WHO Medical Eligibility Criteria (MEC), adapted by MoHFW, grade each condition for each method into four categories.

LAM is a temporary natural method. MoHFW lists three criteria that must all be met: the baby is less than 6 months old, menses have not returned, and the baby is fully or nearly fully breastfed, often, day and night.

As soon as any one criterion fails — periods return, breastfeeds are reduced or bottle feeds start, or the baby reaches 6 months — another method must be started. Other natural methods (calendar, withdrawal) have high typical-use failure: withdrawal fails in about 22% of couples in the first year.

An eligible couple is a currently married couple in which the wife is in the reproductive age group — the textbook definition used in Indian exams (Park) is a wife aged 15–45 years, while NFHS surveys use 15–49 years. Eligible couples are the target group that ASHAs and ANMs counsel about family planning methods in the community.

The couple protection rate (CPR) expresses how many eligible couples are protected by an approved contraceptive method, as a percentage. It is the proxy measure used to judge contraceptive use among eligible couples, and it rises as more couples adopt spacing or permanent methods.