Dr Annabel Forsythe comments on the new guideline “Overweight, Obesity and Contraception" due to be released in spring 2019

Posted 04 Apr 2019

Date: 04 Apr 2019

Author: Annabel Forsythe

FSRH will shortly see the launch of new guidance on Overweight, Obesity and Contraception, written and published by the FSRH CEU. In her blog below, Dr Annabel Forsythe gives an overview of how she thinks this guideline will be useful in day to day consultations.

"Just a quick one doctor – I’m here for my pill"

We’ve all been there, haven’t we? The young woman sitting in front of you wants a repeat combined pill prescription. She has been happily using it for 5 years and loves it – her skin is glowing and her previously heavy and irregular periods are well controlled. Unfortunately, her BMI has just reached the magic number of 35, tipping her into a UKMEC 3. You’ve seen it coming. The moment she walked in your door you started to feel nervous. How can you broach the subject without causing offence? How will she react to a change of method?

Talking about weight is never easy. Many of us wouldn’t dream of telling a friend or family member that they are overweight, let alone a stranger - but in contraception consultations we have to discuss weight issues with increasing regularity. With the 2017 emergency contraception guidance bringing in a BMI threshold of 26 for doubling the dose of Levonorgestrel, it now feels like weight is a discussion point in more consultations than not. Consultation rooms are now equipped with bariatric couches for IUC insertions and we are seeing more and more women for contraception who are undergoing medical or surgical treatment for weight-related issues. The new FSRH guideline “Overweight, Obesity and Contraception” could not have come at a better time. Let me take you through how and why I think it might help…

Overweight Obesity Guideline FSRHWeight Matters

Weight has always been an important matter for the patient and for the clinician. However, the things clinicians worry about and the things patients worry about aren’t always the same. Women seeking contraception are often concerned with how it is going to affect their weight and whether they will have any side effects (good or bad): “How will I feel on this method? Will I gain weight?”. A good clinician will consider these things of course, but in reality, their main concern is around the safety of the method: “Am I going to give my patient a VTE/stroke/MI with this method?” It is when these concerns misalign that conflict can arise.

Helpfully, the new guideline takes us through every contraceptive method in turn, answering the following four key questions:

  • Question 1: Does raised BMI affect contraceptive effectiveness?
  • Question 2: What is the safety of contraceptive use by women with raised BMI?
  • Question 3: Does contraceptive use lead to weight gain among women with raised BMI?
  • Question 4: Are there non-contraceptive health benefits of contraceptive use to women with raised BMI?

Allow me to illustrate through the use of these simple vignettes how these questions might come up in consultations and how the guideline should help you to answer them…*

Does raised BMI affect contraceptive effectiveness?

A 34 year old woman attends clinic requesting an early implant exchange. She has had her implant in situ for 2 years now and this is her third implant. She explains that she “always has her implant changed at 2 years”. She says her doctor told her that due to her weight (BMI 39) the implant would be less effective after 2 years. She has put on more weight since the last insertion and is also worried that this will make it more difficult to remove.

Fortunately, the new guideline clarifies that “the ENG implant can be considered to provide very effective contraception for 3 years for women in all weight/ BMI categories”. Which means we can be more confident in ignoring the rather non-specific statement in the Summary of Product Characteristics (SPC) – “the clinical experience in heavier women in the third year of use is limited. It cannot be excluded that the contraceptive effect may be lower than for women of normal weight. Health professionals may therefore consider earlier replacement of the implant in ‘heavier’ women.”
Furthermore, the guideline reassures that an appropriately placed subdermal implant should be no more difficult to remove in a woman who has a high BMI or who has gained weight since the insertion.

Indeed, the implant is easily palpable and the woman leaves clinic reassured on both counts planning to return in another year.

What is the safety of contraceptive use by women with raised BMI?

A 31 year old woman attends requesting the DMPA injection following her gastric band surgery. She is aware that the injection can lead to weight gain but has used it successfully in the past and has also been told that oral contraception might be less effective and doesn’t like the idea of intrauterine contraception.

On checking the guideline you are able to inform her that there is very limited evidence on contraception use after bariatric surgery; however, both obesity and bariatric surgery are associated with vitamin D deficiency, a risk factor for loss of bone mineral density (BMD). Use of DMPA is also associated with a small loss of BMD. Although the clinical significance of this is unknown you discuss the implant, which she decides to go ahead with instead.

Does contraceptive use lead to weight gain among women with raised BMI?

A 26 year old woman with a BMI of 40 attends for an STI screen. She first had sex with her new boyfriend last night and says she is using the “Natural Cycles” fertility tracking app for contraception. She has tried other methods of contraception but says all hormones make her gain weight. She is on day 15 of an irregular 28-35 day cycle.

Using the new guideline you reassure her that, with the exception of the progestogen-only injectables, there is no evidence of any causal association between hormonal methods and weight gain. Further on in the guideline you also read that although there is no evidence regarding fertility awareness methods (FAM) and raised BMI, her irregular periods mean that she should not rely on her app for contraception. You offer her emergency contraception and she decides to have a Cu-IUD inserted today.

Are there non-contraceptive health benefits of contraceptive use to women with raised BMI?

A 17 year old with a BMI of 36 attends requesting contraception and help with her heavy, painful and irregular periods. She says her friend uses the combined pill which makes her periods much lighter and is interested in starting the same.
With the help of the guideline, you explain to her that the combined pill may not be safe (UKMEC 3 with BMI >35). However, the LNG-IUS is not only safe (UKMEC 1 / 2 with other cardiovascular risk factors) but is highly likely to make her periods lighter and less painful. The guideline also adds that LNG-IUS is likely to reduce the risk of endometrial hyperplasia and cancer that can be associated with obesity.

*Please note the patients in these cases are fictitious and therefore highly compliant.

Other highlights
Finally, I thought I would just draw your attention to some of my personal highlights in the guideline:

  • Approach to issues of weight in contraceptive consultations (section 7) suggests handy hints and tips about how to handle this sensitive issue
  • Contraception and weight management treatment (section 6) describes a pragmatic approach to prescribing contraception in women who are using medical or have undergone surgical treatments for raised BMI
  • Practical considerations with IUC, implant and DMPA (sections 5.1.5, 5.2.5, 5.3.5) provides a reassuring commentary on approaching insertion and removal procedures in women with a raised BMI
  • Barrier methods and Fertility Awareness Methods (sections 5.6 and 5.7) serves as a handy reminder of the methods which many women choose to use but clinicians can be prone to disregard.

I’m sure as you put the guideline into practice you will find your own highlights. I hope it will help us all to navigate these consultations with increased sensitivity and confidence.

Read Annabel's Biography. 

Watch the FSRH's webinar on this guideline. (FSRH Members can watch for free)

Please note, this guideline will be released in spring 2019, this blog post will be updated with a direct link to the guideline when it becomes available.