In a reproductive‑age woman, does replacing an intrauterine device (IUD) create a period of reduced contraceptive effectiveness?

IUD Replacement and Contraceptive Effectiveness

When replacing an IUD, there is no window of reduced contraceptive effectiveness if the new device is inserted immediately after removal of the old one. The key is same-day replacement without any gap between removal and reinsertion.

Immediate Replacement Protocol

The most important principle is that contraceptive protection continues uninterrupted when a new IUD is inserted at the same visit as removal of the expired device. 1

• If you remove an IUD and insert a new one during the same procedure, the woman maintains continuous contraceptive coverage 1
• No backup contraception is needed when immediate replacement occurs 1
• Fertility returns immediately upon IUD removal, so any delay between removal and reinsertion creates a window where pregnancy can occur 2

Timing Considerations for Different IUD Types

Copper IUD Replacement

• The copper T 380A can be placed at any time during the menstrual cycle in non-pregnant women, making same-day replacement straightforward 3
• The device provides immediate contraceptive protection upon insertion 3

Levonorgestrel IUD Replacement

• Prescribing information for levonorgestrel-releasing IUDs technically advises insertion during the first seven days of menses 3
• However, when replacing an existing IUD, immediate insertion at the time of removal maintains contraceptive coverage regardless of cycle timing 1
• If inserting outside the first 7 days of menses when there's been a gap, backup contraception should be used for 7 days 1

Critical Pitfall to Avoid

The main risk occurs when there is ANY delay between IUD removal and new IUD insertion. If a woman has the old IUD removed but doesn't have a new one placed immediately:

• She has no contraceptive protection from that moment forward 2
• If she has had unprotected intercourse in the 5 days before removal, sperm can survive and cause pregnancy after removal 1
• She needs backup contraception (condoms or abstinence) until the new IUD is placed 1

Practical Algorithm

1. Schedule replacement visit before expiration date to ensure device availability 1
2. Remove expired IUD and immediately insert new device during same appointment 1
3. No backup contraception needed with immediate replacement 1
4. If replacement must be delayed: counsel patient to use backup contraception from time of removal until new IUD insertion, or consider leaving the old IUD in place until replacement device is available 1

Additional Clinical Considerations

• Routine follow-up visits are not required after IUD replacement, though women should be advised to return if they have concerns 1
• The risk of pelvic inflammatory disease is only elevated during the first 20 days after insertion, not specifically related to replacement versus initial insertion 1
• Consider checking for IUD strings at routine visits to ensure the device remains properly positioned 1