One thing that breaks my heart and inflames me is when I am in one of the online dietitian / therapist groups I belong to and see an appeal for a recommendation from a gynecologist or fertility doctor who doesn’t tell fat women (I’m using fat as a neutral descriptor, such as low, high, or lean) that they need to lose weight before they get pregnant.
The recommendation to lose weight to increase the chances of a successful and healthy pregnancy is widespread, but without rigorous evidence to support it. So why do many experts, medical societies, public health programs and treatment centers push for weight loss before starting infertility treatment? The answer is a mix of weight bias and epidemiological research showing that there is a Association between “obesity” and infertility. But association is not the same as cause and effect.
“Healthcare professionals know that obesity is associated with major complications in pregnancy. Fertility providers are also aware of the association between obesity and low fertility. The time to pregnancy can be double that of women with a high BMI [body mass index]”Said Angela Thyer, physician and founding partner of Seattle Reproductive Medicine. “It is from these historical studies that doctors speculated that if women could lose weight, they could improve their time to conception and fertility. They recommended weight loss without knowing if it really helped. “
A recent randomized controlled trial, the kind of study that can prove cause and effect, found that weight loss didn’t help. Findings from the FIT-PLESE study, published in January in PLOS Medicine, found that in 379 women with a BMI of 30 or greater and unexplained infertility – unexplained, because the women were ovulating normally – an intensive weight loss intervention of 16 weeks that included a low-calorie diet, physical activity (increasing step counts up to 10,000 per day), and medications that reduce fat absorption were no better at improving fertility or childbirth results than an intervention that simply had increased physical activity. This was despite the fact that the women in the weight loss surgery lost about 7% of their initial weight. The authors concluded that there is no strong evidence to recommend weight loss before conception in women who have a BMI in the “obese” range and unexplained infertility.
“It takes well-designed studies like this to change the existing dogma,” Thyer said, adding that this study was surprising to many providers because it disproved long-held beliefs about weight loss and fertility. “Now, we can confidently say that there is no evidence that weight loss improves conception in obese or overweight women with ovulatory infertility.”
While the study may have been surprising, it has company. A 2016 randomized controlled trial published in the New England Journal of Medicine found that women with infertility – some who were ovulating regularly and others not – who underwent a similar intervention that involved a low-calorie diet had fewer healthy births than women who did not. they made him try to lose weight.
“A reduction in body fat may be helpful in reducing insulin resistance and inflammation, which can improve conception rates,” said registered dietitian Judy Simon, owner of Mind Body Nutrition. “But if a person decides to follow a strict calorie restricted diet, they are more likely to lack key nutrients that optimize fertility and pregnancy. I am amazed that a woman could have a medium or low BMI and be cleared for IVF [in vitro fertilization], however, she may have an eating disorder and be poorly fed. In fact, women who report to a fertility clinic are more likely to have a past or current eating disorder. Weight is not the same as health, especially when dietary and lifestyle habits are taken into account ”.
Thyer said that if weight loss can help a specific patient for a specific purpose, it needs to be approached with compassion and ideally, with expert guidance. “When weight loss is recommended without direction, patients can leave medical care feeling down and down and disappear for years,” she said. “And we know that as women get older, their fertility also decreases. Unfortunately I saw women in my studio where this happened ”.
For more than a decade, Simon and Thyer, who have been talking about “Control Your Weight Sprain at the Door: How to Be a Health Care Provider to Affirm Your Body” at the Seattle Reproductive Symposium in May, offered food classes for the fertility focused on learning food skills, including meal planning and cooking together, and adopting lifestyle changes in a support group setting. “Many of our participants who were preparing for IVF actually conceived naturally after eating regularly and feeling more confident in their bodies,” Simon said. All without focusing on weight loss.
“We don’t stop fertility treatments on any woman because of BMI,” Thyer said. “We encourage all women to optimize their lifestyle before conception by following a plant diet, whole foods, pro-fertility, doing regular activity every day, reducing the use of substances such as alcohol, tobacco and cannabis, aiming to a restful and restorative sleep, reducing stress and maintaining a loving and supportive network of friends and family while on the road to pregnancy ”.
Some providers may still recommend weight loss based on previous information, Thyer said. “Fortunately, the tide is turning. Many providers are now aware that weight loss alone may not help fertility for most patients with higher BMIs. Many are also aware of the fact that restrictive diets are unhealthy, they risk failing over time, and that the weight cycle is worse than maintaining your current weight ”.
Simon said he has had patients with a BMI above 55 who have been rejected by fertility clinics. “Luckily they found another help,” he said, adding that dealing with infertility is already stressful and when women feel guilty and ashamed of their size, it can damage their mental health. “I have had great success working with women with fat bodies who sustain themselves during pre-conception pregnancy and after childbirth. I support them by supporting themselves and their size ”.