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- 26 April 2022
Page last updated April 2022
How BMI is being used to gatekeep fertility treatment

Lynsey was 38 when she and her husband started trying for a baby in 2019. After six months of trying to conceive without success, they sought tests at a private fertility clinic, where Lynsey was told that her egg count was low due to age.
Believing she was eligible for NHS-funded IVF, she returned to the NHS for a referral. “BMI was never raised by any medical professionals until I had the meeting with the final doctor at the hospital who told me my BMI was too high for them to give me IVF,” she says.
Lynsey’s BMI was 31, one point above the upper limit set by her local clinical commissioning group. “I never even knew my BMI would be a deciding factor,” Lynsey recalls. Medical professionals had never raised it as a problem before.
Lynsey isn’t alone. Limits on IVF according to BMI are imposed by almost all clinical commissioning groups (CCGs), who are responsible for commissioning and organising delivery of NHS services.
The assumed positive impact of weight loss on conception and pregnancy outcomes is seen as so great that its possible negative effects are ignored
According to research by reproductive healthcare charity BPAS on the provision of NHS-funded IVF treatment in 2020, 130 CCGs (96% of the total) in England specified a maximum female BMI.1
A BMI of 30 or more is considered “obese”. Many studies have found an association between higher BMIs and infertility. However, just because two factors are related, it doesn’t mean that one causes the other.
Plus, while a higher BMI may come with risks, the ACOG notes that it’s perfectly possible to have a healthy pregnancy while “obese”.
Some advocates, like Amber Marshall, who created Big Birthas to help women with BMIs of 30 and over access equitable healthcare during pregnancy and birth, feel that prejudice against “obese” people makes medical professionals over-focus on BMI.
As a result, the assumed positive impact of weight loss on conception and pregnancy outcomes is seen as so great that its possible negative effects are ignored.
“The sad reality of the NHS is that supply doesn’t meet demand and so treatment has to be rationed one way or another”
For instance, deferring fertility treatment until after weight loss means that a person’s eggs will be older when treatment begins. IVF has a success rate of 19% for those aged 38 to 39. But for people aged 40 to 42, the rate drops to 11%.2
IVF is an expensive treatment with low success rates, and some medical professionals argue that gatekeeping fertility treatment by using BMI cut-offs is justified to protect scarce NHS resources.
“The sad reality of the NHS is that supply doesn’t meet demand and so treatment has to be rationed one way or another,” says Dr Toni Hazell, a London GP. “Success rates for IVF are lower in women with obesity and so a BMI cut-off of 30 is often used.”
Dr Hazell adds that weight loss is not as simple as eating less and moving more, and that professional support isn’t always available. “Losing weight isn’t easy and NHS services for obesity are over-subscribed, often with long waiting lists. This can be very challenging for women who are already having a very stressful time due to their difficulty in conceiving.”
“Nobody disclosed it [until] I had already gone there. I had already paid; I had already done all the exams”
What about the private sector? Marianthi, a non-binary lesbian, knew from the start of their parenthood journey that accessing NHS treatment would be difficult. Their CCG’s policy expressly requires those wishing to conceive to self-fund six rounds of IUI before accessing NHS funding. And their “severely obese” BMI would disqualify them anyway.
When Marianthi found a private fertility clinic that took them on as a patient, staff were not forthcoming about their BMI policies. “Nobody disclosed it [until] I had already gone there. I had already paid; I had already done all the exams,” they say.
A consultant they met at the clinic acknowledged that, weight aside, Marianthi had a clean bill of health and normal fertility. Nonetheless, he advised them to return after losing 20kg.
If someone can conceive without medical intervention, doctors can’t stop them from doing so, regardless of their BMI. Lynsey fell pregnant naturally two weeks after her 40th birthday, and recently gave birth to a healthy baby girl.
Doctors at the private clinic were not guarding NHS resources when they refused Marianthi treatment, instead citing the importance of a healthy pregnancy to justify their “advice”
But for people who can’t conceive through intercourse, being refused treatment due to their BMI can mean resorting to DIY assisted conception. Marianthi is currently trying to conceive using a sperm donor they met online, without the medical supervision of the clinic.
Marianthi’s experience complicates the narrative that BMI thresholds exist to protect NHS resources. Doctors at the private clinic were not guarding NHS resources when they refused Marianthi treatment, instead citing the importance of a healthy pregnancy to justify their “advice”.
However, negative experiences with health professionals may contribute to adverse outcomes in “obese” people’s pregnancies and births. For example, some may avoid healthcare settings due to stigmatising treatment.3 This is worrying, as receiving specialist care has been linked to better birth outcomes for “obese” women.4
If fertility care providers are serious about the health of all parents and babies, they must listen to “obese” people when they say they feel discriminated against.
Featured image is an illustration of a feminine-presenting plus-sized person sitting on a sofa in a waiting room. They are resting their face on their arm as if waiting intently
Page last updated April 2022
Lynsey was 38 when she and her husband started trying for a baby in 2019. After six months of trying to conceive without success, they sought tests at a private fertility clinic, where Lynsey was told that her egg count was low due to age.
Believing she was eligible for NHS-funded IVF, she returned to the NHS for a referral. “BMI was never raised by any medical professionals until I had the meeting with the final doctor at the hospital who told me my BMI was too high for them to give me IVF,” she says.
Lynsey’s BMI was 31, one point above the upper limit set by her local clinical commissioning group. “I never even knew my BMI would be a deciding factor,” Lynsey recalls. Medical professionals had never raised it as a problem before.
Lynsey isn’t alone. Limits on IVF according to BMI are imposed by almost all clinical commissioning groups (CCGs), who are responsible for commissioning and organising delivery of NHS services.
The assumed positive impact of weight loss on conception and pregnancy outcomes is seen as so great that its possible negative effects are ignored
According to research by reproductive healthcare charity BPAS on the provision of NHS-funded IVF treatment in 2020, 130 CCGs (96% of the total) in England specified a maximum female BMI.1
A BMI of 30 or more is considered “obese”. Many studies have found an association between higher BMIs and infertility. However, just because two factors are related, it doesn’t mean that one causes the other.
Plus, while a higher BMI may come with risks, the ACOG notes that it’s perfectly possible to have a healthy pregnancy while “obese”.
Some advocates, like Amber Marshall, who created Big Birthas to help women with BMIs of 30 and over access equitable healthcare during pregnancy and birth, feel that prejudice against “obese” people makes medical professionals over-focus on BMI.
As a result, the assumed positive impact of weight loss on conception and pregnancy outcomes is seen as so great that its possible negative effects are ignored.
“The sad reality of the NHS is that supply doesn’t meet demand and so treatment has to be rationed one way or another”
For instance, deferring fertility treatment until after weight loss means that a person’s eggs will be older when treatment begins. IVF has a success rate of 19% for those aged 38 to 39. But for people aged 40 to 42, the rate drops to 11%.2
IVF is an expensive treatment with low success rates, and some medical professionals argue that gatekeeping fertility treatment by using BMI cut-offs is justified to protect scarce NHS resources.
“The sad reality of the NHS is that supply doesn’t meet demand and so treatment has to be rationed one way or another,” says Dr Toni Hazell, a London GP. “Success rates for IVF are lower in women with obesity and so a BMI cut-off of 30 is often used.”
Dr Hazell adds that weight loss is not as simple as eating less and moving more, and that professional support isn’t always available. “Losing weight isn’t easy and NHS services for obesity are over-subscribed, often with long waiting lists. This can be very challenging for women who are already having a very stressful time due to their difficulty in conceiving.”
“Nobody disclosed it [until] I had already gone there. I had already paid; I had already done all the exams”
What about the private sector? Marianthi, a non-binary lesbian, knew from the start of their parenthood journey that accessing NHS treatment would be difficult. Their CCG’s policy expressly requires those wishing to conceive to self-fund six rounds of IUI before accessing NHS funding. And their “severely obese” BMI would disqualify them anyway.
When Marianthi found a private fertility clinic that took them on as a patient, staff were not forthcoming about their BMI policies. “Nobody disclosed it [until] I had already gone there. I had already paid; I had already done all the exams,” they say.
A consultant they met at the clinic acknowledged that, weight aside, Marianthi had a clean bill of health and normal fertility. Nonetheless, he advised them to return after losing 20kg.
If someone can conceive without medical intervention, doctors can’t stop them from doing so, regardless of their BMI. Lynsey fell pregnant naturally two weeks after her 40th birthday, and recently gave birth to a healthy baby girl.
Doctors at the private clinic were not guarding NHS resources when they refused Marianthi treatment, instead citing the importance of a healthy pregnancy to justify their “advice”
But for people who can’t conceive through intercourse, being refused treatment due to their BMI can mean resorting to DIY assisted conception. Marianthi is currently trying to conceive using a sperm donor they met online, without the medical supervision of the clinic.
Marianthi’s experience complicates the narrative that BMI thresholds exist to protect NHS resources. Doctors at the private clinic were not guarding NHS resources when they refused Marianthi treatment, instead citing the importance of a healthy pregnancy to justify their “advice”.
However, negative experiences with health professionals may contribute to adverse outcomes in “obese” people’s pregnancies and births. For example, some may avoid healthcare settings due to stigmatising treatment.3 This is worrying, as receiving specialist care has been linked to better birth outcomes for “obese” women.4
If fertility care providers are serious about the health of all parents and babies, they must listen to “obese” people when they say they feel discriminated against.
Featured image is an illustration of a feminine-presenting plus-sized person sitting on a sofa in a waiting room. They are resting their face on their arm as if waiting intently
Page last updated April 2022
References
- BPAS, BPAS investigation into the IVF postcode lottery: an examination of CCG policy for the provision of fertility services, British Pregnancy Advisory Service, August 2020 [online] [accessed 26 April 2022]
- NHS, IVF – Overview, NHS website, October 2021 [online] [accessed 26 April 2022]
- Flint, S.W., Time to end weight stigma in healthcare, eClinicalMedicine (The Lancet), April 2021, Vol 34, no 100810
- Denison, F.C., et al., Does attendance at specialist antenatal clinic improve clinical outcomes in women with class III obesity compared with standard care? A retrospective case-note analysis, BMJ Open, 2017, vol 7, issue 5