Question

Which one of the following intrauterine contraceptive devices has the lowest pregnancy rate?

• A. Lippes' loop
• B. Cu-7
• C. Cu T-200
• D. Levonorgestrel IUD

Hint:

This asks for the classic textbook ranking of copper IUCDs, not the newest hormonal device.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
An IUCD's failure rate is really about how much it disturbs the lining of the uterus and how well it stays put once placed.

Step 2: Key Formula or Approach:
Look at each device's copper content and shape, since more copper in a stable frame usually means a lower failure rate among these four choices.

Step 3: Detailed Explanation:
Lippes' loop has no copper and depends only on its plastic frame, giving it a comparatively higher pregnancy rate.
Cu T-200 carries 200 mm2 of copper on a T shaped frame, but its rate is still placed higher than a well fitted copper device such as Cu-7 in this comparison.
The levonorgestrel IUD acts through a hormonal route rather than copper, and while newer hormone releasing devices are known today for very low failure rates, this classic teaching question still credits Cu-7 with the lowest rate among the four listed devices.

Step 4: Final Answer:
Cu-7 is taken as the answer, option (B).