Efficacy, duration of use and assessing suitability

Efficacy

Pearl Indices (number of pregnancies per 100 users) for the different devices are generally reported as:

  • 1–0.2 for 52 mg LNG-IUD over 5–7 years
  • 3 for 19.5 mg LNG-IUD over 3–5 years
  • 3 for 13.5 mg LNG-IUD over 3 years.

 

The contraceptive effectiveness of LNG-IUD is not affected by use of enzyme-inducing drugs or weight/BMI, but there is an increased risk of expulsion if BMI > 25

 

Duration of Use

In individuals aged over 50 years with an LNG-IUD wishing to stop contraception use before age 55 years, take an FSH level and if >30 IU/L, they can stop contraception after one further year. If removing an LNG-IUD because contraception is no longer required, ensure they are not using it for endometrial protection as part of HRT.

 

See appendix one for Comparison of the product characteristics of LNG-IUD devices currently available in the UK

13.5 mg LNG-IUD for contraception

Jaydess®

3 years

19.5 mg LNG-IUD for contraception

Kyleena®

5 years

52 mg LNG-IUD for contraception

Beneilxa®, Levosert®, Mirena®,

Inserted age under 45 : 8 years

Inserted age 45 and over: retain until age 55

52 mg LNG-IUD as part of HRT

Beneilxa®, Levosert®, Mirena®

5 years

 

 

Assessing Suitability

Few medical conditions contraindicate use of LNG-IUD (see UKMEC (2016 https://www.fsrh.org/documents/ukmec-2016/)

 

The use of the LNG-IUD is contraindicated if there is a known or suspected allergy or hypersensitivity to any of the components of the device.

 

Editorial Information

Last reviewed: 25/08/2023

Next review date: 01/10/2025

Author(s): West of Scotland Managed Clinical Network in Sexual Health Clinical Guidelines Group .

Version: 10.1

Approved By: West of Scotland Managed Clinical Network in Sexual Health

Reviewer name(s): George Laird.