Discussing Obesity and Fertility with FormHealth
Contributed By Dr. Florencia Halperin
As an endocrinologist specializing in obesity medicine, few things are more rewarding for me than working with women who are trying to lose weight to get healthy for a pregnancy. I also know that both weight and fertility can be tough subjects to address and can stir up difficult and deep-seated emotions. I recently talked with Dr. Abbaa Sarhan, a reproductive endocrinologist from Genetics & IVF Institute (GIVF) in Fairfax, VA, about the intersection between obesity and fertility. Together, our work is designed to bring hope to patients on their fertility journey, because with the right expertise and the right support, women can lose weight as part of their fertility plan — no matter how hard it has been in the past. An open conversation about the facts is a great place to start.
What is the relationship between obesity and fertility?
Obesity is defined as a body mass index (BMI) above 30 mg/kg2. Because obesity is so common (more than 40% of Americans have obesity), 25% of women in the US who become pregnant have obesity. A lot of research has shown that obesity adversely impacts a woman’s chance of becoming pregnant: rates of natural pregnancy are lower as BMI gets higher. It is also true that a woman with excess weight before pregnancy is at a greater risk of many complications during a pregnancy that can affect her own health (such as high blood pressure and gestational diabetes) and that of the baby (such as birth weight).
“In fact, even when assisted reproductive technology like in-vitro fertilization (IVF) is utilized to treat infertility, patients with higher BMIs have lower pregnancy and livebirth rates as well as higher miscarriages,” said Dr. Sarhan.
What is it about body fat that affects fertility?
The biology that underlies the relationship between body fat and the ability to become pregnant is fascinating–but complicated. Adipose tissue (fat, as we know it) is very important for hormone regulation. Adipose cells convert male hormones to female hormones, so having excess fat tissue can disrupt the fine balance between male and female hormone levels. And this in turn can disrupt the elegant cycles that result in the reproductive system releasing eggs (ovulation). So, women who have higher BMI have lower rates of ovulation. However, this is not the full story, because even when they have normal ovulation, women with obesity have lower pregnancy rates. “In fact, even when assisted reproductive technology like in-vitro fertilization (IVF) is utilized to treat infertility, patients with higher BMIs have lower pregnancy and livebirth rates as well as higher miscarriages,” said Dr. Sarhan. “They also require higher doses of fertility medications which can be costly. These outcomes point to obesity’s negative impact on both egg quality and endometrial receptivity.”
Obesity affects male fertility as well. Men with obesity are more likely to have low sperm count and motility (ability to swim). Men who have excess weight can have increased body temperatures and higher female hormone levels, both of which impair fertility.
Does weight loss improve fertility?
Research has shown that if a woman with obesity can lose weight, she is more likely to get pregnant. In fact, losing just 10% of starting weight helps regulate the menstrual cycle, and increase rates of ovulation and spontaneous pregnancy. Pregnancies that start at a lower weight also have lower rates of complications for the mother and the baby.
What about weight loss for women who need assisted reproductive technology such as IVF?
What we know about how weight loss impacts success rates for women who need assisted reproductive technology such as IVF comes from two large randomized controlled trials which studied diet, exercise, and weight loss interventions in women with obesity interested in pregnancy. Women who lost weight before undergoing IVF had increased likelihood of becoming pregnant spontaneously. Women who lost weight and still needed IVF did not have higher rates of live births, but during their pregnancies had lower risk of high blood pressure, pre-term birth and metabolic syndrome/insulin resistance.
And beyond the research, a very important consideration for women who have obesity as well as infertility is that in most centers across the US, a BMI below 45 is required to undergo IVF. In addition to the increased chance of success, Dr. Sarhan explained that the BMI limit is for our patient’s safety as there is an increased risk of complications during procedures that use anesthesia for patients with a BMI over 45.” For women with a BMI above 45, achieving weight loss can mean the difference between being offered the treatment or being ineligible for it,” she explained.
Can women with infertility and obesity be successful at weight loss?
Absolutely. Weight loss is possible even for women who have struggled with their weight for a long time and who are also going through fertility treatments that can affect their weight.
Many people are not aware of a subspecialty of medicine called obesity medicine, which focuses on helping individuals lose weight to improve their health. Obesity medicine specialists work to understand the many factors that contribute to a person’s weight, and to evaluate the many ways in which weight is affecting the person’s health. Then they use a wide range of science-backed methods to help each patient find their unique path to successful weight loss. Weight management is usually a team effort and works best when it also leverages the experience of other health care professionals, such as dietitians.
At Form Health, we pair each patient with a board-certified physician and a weight management dietitian. We work with patients on incremental changes that add up to a healthy mindset and a healthy lifestyle. Like Dr. Sarhan, we are dedicated to empowering patients by educating and counseling them about their choices so they can make the best-informed decisions leading up-to and during their fertility journey. The goal is establishing habits that can be continued during pregnancy and beyond – because avoiding excess weight gain during pregnancy is key, since postpartum weight retention is a fact of life. Our care plan, from video visits to messaging and more, is delivered through a secure smartphone app to make it as convenient as possible to get the kind of support that we know successful weight loss requires. Our team works closely with the fertility specialist towards the mutual goal of helping our patients have healthy pregnancies and healthy babies.
“The team-based approach and modern model of care that Form Health uses is the perfect complement to how we practice at GIVF,” explained Dr. Sarhan, “and I know when I refer a patient to the Form Health team they will feel supported, and their care plan will be part of their pathway to parenthood. It doesn’t feel like I’m sending them off to lose weight on their own, because I’m not.”
Although it can be challenging to discuss obesity and fertility, there are positive steps anyone can take towards getting healthier as part of planning for pregnancy. Women who want to become pregnant are uniquely motivated to achieve their health goals, and with the right medical expertise and support from a compassionate team, weight loss is possible.
For more information on how Form Health can help you, please visit our website: formhealth.co or give us a call (617) 505-1520.