Question

Out of 100 women who were offered ocp for contraception 10 women got pregnant when followed for 24 months. What is Pearl's index?

• A. 10
• B. 5
• C. 4
• D. 2

Answer 1

The Correct Option is B

Pearl's Index is a calculation used to estimate the number of accidental pregnancies per 100 women-years of exposure to a contraceptive method. It is calculated as follows:

$$ Pearl's \ Index = \left( \frac{\text{Number of pregnancies} \times 12}{\text{Number of women} \times \text{Number of months observed}} \right) \times 100 $$

In this scenario:

• Number of pregnancies = 10
• Number of women = 100
• Number of months observed = 24

Substitute the values into the formula:

$$ Pearl's \ Index = \left( \frac{10 \times 12}{100 \times 24} \right) \times 100 $$

First, calculate the numerator:

$$ 10 \times 12 = 120 $$

Then calculate the denominator:

$$ 100 \times 24 = 2400 $$

Now divide the numerator by the denominator:

$$ \frac{120}{2400} = 0.05 $$

Finally, multiply by 100 to get the Pearl's Index:

$$ 0.05 \times 100 = 5 $$

Therefore, the Pearl's Index is 5.