If 100 couples have used a method for a period of 2 years and have resulted in 10 pregnancies, what will be the effectiveness of the method used?
Moderate
The correct answer is Moderate. Contraceptive effectiveness is measured by the Pearl Index — accidental pregnancies per 100 woman-years of exposure — calculated as (pregnancies x 1200) / total months of exposure. Here exposure is 100 couples x 24 months = 2400 woman-months with 10 pregnancies, giving (10 x 1200) / 2400 = 5 per 100 woman-years. A failure rate of about 5 per HWY places the method in the moderately effective band, comparable to typical-use condoms or the diaphragm.
High effectiveness needs failure rates well below 1 per HWY — perfect-use combined pills (0.1), CuT-380A (0.6–0.8), implants and sterilisation — several-fold better than 5. Low effectiveness applies to methods failing 10–25 per HWY, such as periodic abstinence, withdrawal or spermicides alone, which is far worse than 5. Cannot be commented is wrong because all three variables needed — number of couples, duration and pregnancies — are given, so the index is fully calculable.
Key point: Always convert to woman-years: pregnancies x 1200 divided by total months of use. The Pearl Index assumes a constant failure rate over time, which is why life-table analysis is preferred for long-duration methods.
Similar Questions
Which of the following statements regarding lactational amenorrhea method are correct?
1. It is equally effective in amenorrheic as well as menstruating woman if the woman is exclusively breastfeeding.
2. The risk of pregnancy in amenorrheic woman who is exclusively breastfeeding is less than 2% in the first 6 months.
3. It requires exclusive breastfeeding for 6 months.
4. The failure rate for exclusively breastfeeding and menstruating women is 15-20%.
Select the answer using the code given below.
Important Questions from Conventional Contraceptives
- Which one of the following statements regarding contraception is NOT true?
- Which of the following are correct regarding failure rate of contraceptive methods?
1. Depot medroxyprogesterone ace-tate 0 to 1 per HWY
2. Norplant 0-1 per HWY
3. LNG-IUS 0.02 per HWY
4. Levonorgestrel 3 per HWY
Select the correct answer using the code given below : - Injectable medroxyprogesterone IP 150 mg/mL contraceptive injection is available in Family Health Programme of the Government of India under the name
- A 25-year-old newly married female on liver enzyme inducers is requesting contraceptive advice in family planning clinic. Which of the following would be the most reliable method of contraception for her?
- Amongst the following, the Pearl Index is highest with
