According to the Centers for Disease Control and Prevention, over one-third of American women in their childbearing years are obese; in Europe, the World Health Organization estimates that 23 percent of women are obese. This means that reproductive specialists are increasingly addressing the fertility needs of patients with a high BMI.
The already emotional process of trying to conceive can be even more fraught for your overweight and obese patients. Increased weight not only poses health risks, but also decreases the chances of conception and a healthy pregnancy.
A 2019 article on BMI and IVF published in the Journal of Assisted Reproduction and Genetics called for a national professional organization to issue clinical guidelines outlining "consistent, fair and safe" treatment recommendations for high BMI patients seeking fertility assistance.
While there are currently no ironclad rules for clinicians navigating the discussion around fertility and body weight, demonstrating sensitivity while discussing BMI and IVF can help you navigate this difficult topic with patients.
The Relationship Between BMI and IVF Outcomes
High body weight presents numerous fertility challenges. A high BMI contributes to anovulation, irregular menstrual cycles, adverse oocyte quality and hormonal imbalances. Although more research is needed to explore how BMI influences female fertility, estrogen and leptin appear to play a role in regulating both BMI and reproductive physiology.
An increasing share of patients who are overweight or obese are seeking fertility assistance, presenting unique clinical issues. Research published in Human Reproduction Update suggests that women with obesity may experience significantly fewer live births after IVF than women at a lower BMI. Obese women are also more prone to preterm births and pregnancy complications.
Although your higher BMI patients may be aware of these challenges, the vast majority may resist more than a three-month delay in infertility treatment to allow for weight loss attempts, according to findings published in Obesity Research and Clinical Practice.
Further complicating the issue, recent research has cast doubt on the effectiveness of weight loss immediately prior to IVF. In a study published in Human Reproduction, researchers in three Nordic countries performed a randomized, controlled study comparing women with a BMI above 30 who dropped a mean of 20 pounds and women with the same BMI who did not lose weight. They found no statistical difference in pregnancy outcomes between the two groups.
Promoting a positive message about weight loss well before an infertility workup may be beneficial, as some patients may be more receptive to this information earlier in the process. The American College of Obstetricians and Gynecologists encourages clinicians to offer preconception counseling to patients who meet the definition of overweight or obese. You may also want to consider promoting appropriate weight loss methods for other health reasons well before your patients are actively pursuing parenthood.
Evaluating High BMI Patients for Fertility Treatment
Ultrasound has long been an essential tool in clinical fertility practice. Performing ultrasound on high BMI patients, however, can present novel challenges. While endocavity scanning is the preferred method of evaluation, if it is not an option (if patient refuses or it is not well tolerated), then transabdominal should be considered. Due to the increased depths required to account for the adipose tissue layer, however, energy is absorbed and refracted, causing back-scatter and resulting in image degradation.
Shortening the distance between the uterus and transducer may help clarify these images. Consider lifting and scanning under the panniculus just over the pubic bone, or imaging while your patient's bladder is full, which naturally lifts the uterus closer to the abdominal wall for better viewing.
Demonstrating compassion with patients of higher body weight can go a long way in fostering excellent doctor-patient relationships. Ensure them that their fertility journey may present more challenges, but is not without hope, and that you will be there to guide them every step of the way.
