Higher-Weight Patients and Fertility
Collaboration with Nicola Salmon Part 2
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This is the second article from Nicola Salmon, fat-positive fertility coach and author of “Fat and Fertile" who agreed to work with me on a series of articles for the newsletter. You can find the first piece (about gyn care and PCOS) here. I am so very thankful for her expertise! Please check out her work at http://nicolasalmon.co.uk/
A quick note – Nicola has included end note references here, please be aware that the studies cited often come from a place of weight bias and pathologizing higher-weight bodies in harmful ways and can be triggering.
When folks in larger bodies decide that they want to grow their family, they are often met with stigmatizing comments and recommendations, from friends, family, healthcare professionals and even their own internal dialogue. It’s a common belief within our culture that fat folks will have a harder time getting pregnant, a more “risky” pregnancy and that their weight could impact the health of their future child. So naturally weight loss is strongly encouraged from all camps.
The underlying wrongful assumption is that fat people are unhealthy and that any form of weight loss would improve the health of the person and their future pregnancy and child.
There are many studies that explore weight loss and fertility for people with higher weight bodies but the evidence is far from black and white and misses some key nuances that are essential to think about when discussing weight loss and fertility.
One systematic review and meta-analysis (1) looked at 40 studies and concluded that dieting and exercise were effective forms of intervention but when we look more closely at the results, it’s not that simple. Data aggregated from five randomized control trials showed that there was no difference in live births between the intervention group vs the control group. Studies that were included without control groups reported lower rates than expected results with diet and exercise and no difference was seen in outcomes for folks who participated in IVF.
So why are the results so varied? None of the studies have separated out the benefits of the change in health promoting behaviors that often come with recommending diet and exercise to promote weight loss.
Often doctors recommend that losing “5-10%” of weight will have a positive impact on their fertility (2) but if you are suggesting that BMI impacts fertility then losing a percentage of your body weight makes no sense as folks in higher weight bodies will still be considered as “unhealthy” with a 5% weight loss. What makes more sense is that these folks are altering their behaviors and it’s the behaviors that are impacting their health and fertility. In reality, the weight doesn’t matter.
The main issue with recommending weight loss however, is that it assumes that weight loss is risk-free.
There is overwhelming evidence that shows any form of intentional weight loss has no long term success. Due to the fact that any form of intentional weight loss is only ever short term, the majority of participants will experience weight cycling, where weight increases and decreases over time, which is independently linked to harm.
Fat people are more likely to have experienced weight cycling in their lives, and that risk indicator isn’t accounted for in studies about their health.
Weight cycling has been shown to negatively affect health by increasing chronic inflammation (3). Chronic inflammation can affect ovulation and hormone production (4) and is linked with the occurrence of many fertility issues such as PCOS (5) and endometriosis (6).
Weight stigma is the prejudice that fat people face. It's normalized within our society and healthcare systems. When these beliefs are internalized, meaning that fat people also believe them to be true, they may avoid seeking help with their fertility, especially when it proves to be difficult. For all the research out there on weight and fertility, there is no research specifically investigating the access that fat people have to fertility support. However, a study looking at how body weight impacted routine gynecological and breast checks (7) found that an increase in BMI led to a decrease in accessing preventative healthcare. Fat people seeking to get pregnant have reason to fear being stigmatized because of their body size. They might even blame themselves for any fertility issues they encounter and feel too ashamed to go to the doctor for help.
Weight stigma is also linked to an increase in chronic inflammation (8) due to the stress that fat people face when they have interactions with their healthcare professionals. Weight stigma means that it takes longer for people to receive fertility support and we know that time is an important factor. Weight cycling and weight stigma are never taken into account in the research on BMI and fertility or pregnancy.
There are also several studies that show dieting and weight loss has a negative impact on fertility. A study (9) where participants undertook a very low calorie diet had to be suspended due to its impact on egg quality and fertilization rates. Another study (10) reviewed the current literature and found two large well-conducted RCTs consistently showed that short-term weight loss for people with higher BMIs did not improve their live birth outcomes. Einarsson et al (11) showed that an intensive weight reduction program prior to IVF led to people losing weight but also did not impact live birth rates. A systematic review and meta-analysis (12) that looked at the impact of preconception lifestyle interventions. They found an increase in natural pregnancy rate but no increase in ART adverse events, clinical pregnancy, pregnancy complications, delivery complications, live birth, premature birth, birth weight or neonatal mortality.
A final factor that is essential to recognize is the time implications in recommending weight loss. A study looking at the probability of someone attaining a normal BMI showed the annual probability of achieving an BMI of less than 24.9 is 0.8% for women with a BMI of 30-34.9 and is 0.15% of women with an BMI of 40-44.9 (13) yet we know that age plays a significant role in outcomes. For every additional year that fat people are denied appropriate tests and treatment, the probability that they’ll get pregnant decreases by 3.5%. (14)
Fat people need evidence-based, respectful fertility care and choice in how they access that care. By denying fat folks access to care, we are denying them their reproductive rights as stated by the World Health Organization “to decide freely and responsibly the number, spacing and timing of their children and to have the information and means to do so, and the right to attain the highest standard of sexual and reproductive health. They also include the right of all to make decisions concerning reproduction free of discrimination, coercion and violence.” (15)
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More research and resources:
https://haeshealthsheets.com/resources/
*Note on language: I use “fat” as a neutral descriptor as used by the fat activist community, I use “ob*se” and “overw*ight” to acknowledge that these are terms that were created to medicalize and pathologize fat bodies, with roots in racism and specifically anti-Blackness. Please read Sabrina Strings’ Fearing the Black Body – the Racial Origins of Fat Phobia and Da’Shaun Harrison’s Belly of the Beast: The Politics of Anti-Fatness as Anti-Blackness for more on this.
References
1. Best D, Avenell A, Bhattacharya S. How effective are weight-loss interventions for improving fertility in women and men who are overweight or obese? A systematic review and meta-analysis of the evidence. Hum Reprod Update. 2017 Nov 1;23(6):681-705. doi: 10.1093/humupd/dmx027. PMID: 28961722.
2. Balen AH, Anderson RA; Policy & Practice Committee of the BFS. Impact of obesity on female reproductive health: British Fertility Society, Policy and Practice Guidelines. Hum Fertil (Camb). 2007 Dec;10(4):195-206. doi: 10.1080/14647270701731290. PMID: 18049955.
3. Strohacker K, Carpenter KC, McFarlin BK. Consequences of Weight Cycling: An Increase in Disease Risk? Int J Exerc Sci. 2009;2(3):191-201. PMID: 25429313; PMCID: PMC4241770.
4. Weiss G, Goldsmith LT, Taylor RN, Bellet D, Taylor HS. Inflammation in reproductive disorders. Reprod Sci. 2009 Feb;16(2):216-29. doi: 10.1177/1933719108330087. PMID: 19208790; PMCID: PMC3107847.
5. Blumenfeld Z. The Possible Practical Implication of High CRP Levels in PCOS. Clin Med Insights Reprod Health. 2019 Jul 22;13:1179558119861936. doi: 10.1177/1179558119861936. PMID: 31384138; PMCID: PMC6647201.
6. Meng-Hsing W, Kuei-Yang H, Shaw-Jenq T. Endometriosis and possible inflammation markers, Gynecology and Minimally Invasive Therapy 2015, Volume 4, Issue 3 61-67, doi.org/10.1016/j.gmit.2015.05.001.
7. Fontaine KR, Faith MS, Allison DB, Cheskin LJ. Body weight and health care among women in the general population. Arch Fam Med. 1998 Jul-Aug;7(4):381-4. doi: 10.1001/archfami.7.4.381. PMID: 9682694.
8. Tomiyama AJ, Carr D, Granberg EM, Major B, Robinson E, Sutin AR, Brewis A. How and why weight stigma drives the obesity 'epidemic' and harms health. BMC Med. 2018 Aug 15;16(1):123. doi: 10.1186/s12916-018-1116-5. PMID: 30107800; PMCID: PMC6092785.
9. Tsagareli V, Noakes M, Norman RJ. Effect of a very-low-calorie diet on in vitro fertilization outcomes. Fertil Steril. 2006 Jul;86(1):227-9. doi: 10.1016/j.fertnstert.2005.12.041. Epub 2006 Jun 5. PMID: 16750829.
10. Gaskins AJ. Recent advances in understanding the relationship between long- and short-term weight change and fertility. F1000Res. 2018 Oct 26;7:F1000 Faculty Rev-1702. doi: 10.12688/f1000research.15278.1. PMID: 30416711; PMCID: PMC6206616.
11. Einarsson S, Bergh C, Friberg B, Pinborg A, Klajnbard A, Karlström PO, Kluge L, Larsson I, Loft A, Mikkelsen-Englund AL, Stenlöf K, Wistrand A, Thurin-Kjellberg A. Weight reduction intervention for obese infertile women prior to IVF: a randomized controlled trial. Hum Reprod. 2017 Aug 1;32(8):1621-1630. doi: 10.1093/humrep/dex235. PMID: 28854592.
12. Lan L, Harrison CL, Misso M, Hill B, Teede HJ, Mol BW, Moran LJ. Systematic review and meta-analysis of the impact of preconception lifestyle interventions on fertility, obstetric, fetal, anthropometric and metabolic outcomes in men and women. Hum Reprod. 2017 Sep 1;32(9):1925-1940. doi: 10.1093/humrep/dex241. PMID: 28854715.
13. Fildes A, Charlton J, Rudisill C, Littlejohns P, Prevost AT, Gulliford MC. Probability of an Obese Person Attaining Normal Body Weight: Cohort Study Using Electronic Health Records. Am J Public Health. 2015 Sep;105(9):e54-9. doi: 10.2105/AJPH.2015.302773. Epub 2015 Jul 16. PMID: 26180980; PMCID: PMC4539812.
14. van Noord-Zaadstra BM, Looman CW, Alsbach H, Habbema JD, te Velde ER, Karbaat J. Delaying childbearing: effect of age on fecundity and outcome of pregnancy. BMJ. 1991 Jun 8;302(6789):1361-5. doi: 10.1136/bmj.302.6789.1361. PMID: 2059713; PMCID: PMC1670055.
15. World Health Organisation. Sexual and reproductive health and rights: a global development, health, and human rights priority. 2014 July [cited 2021 Oct 14] Available at: https://www.who.int/reproductivehealth/publications/gender_rights/srh-rights-comment/en/