Your Weight and Fertility

We are honored to have Dr. Stephanie Gustin from Heartland Reproductive Center in Omaha, Nebraska, tackle a sensitive topic with fertility: Weight. It’s not a fun topic to talk about because while we are always talking about the pains of losing weight, we rarely talk about HOW it effects our fertility.

“Your fertility and your weight. Arguably, weight (be it under or over) is one of the hardest subjects to address.  For many, it can be an emotionally charged topic, embedded in lasting wounds since childhood or adolescence. So much so, that some providers avoid the topic all together, given their personal angst in approaching the conversation, fearing a dichotomy between their intent and the patient’s perception.  

But here’s the thing, as a physician with a strong family history of overweight and/or obese women, who has her own personal history of gestational diabetes (twice!!) and now has impaired glucose tolerance, I am empowered to understand that my diet and my body composition has the potential to both positively and negatively affect my future health.

The question is, how does weight affect fertility?  And if it does, does alteration in weight (loss or gain) positively affect your outcome? Let’s do a deep dive of the existing literature, and I’ll let you (in concert with your provider) decide what is best for your particular case, armed with the most up to date information!

B M I, does it matter? Infrequent (oligo) or anovulation (lack of ovulation) is the most common cause of infertility amongst underweight (BMI < 18) and obese women (BMI > 30). So if we can circumvent that by inducing ovulation, does BMI matter?

A recent study by Whynott R, et al. F&S. 2020 attempted to answer this question.
A retrospective study (data review, no intervention to monitor for causal relationship) of 3,217 intrauterine insemination treatment cycles in 1,306 patients.

Baseline characteristics:
The BMI ranged from 18.5 to 53.1 kg/m2
47% percent of cycles were in normal weight women (BMI 18.5–24.99 kg/m2)
24.1% in over-weight women (BMI 25–29.99 kg/m2)
28.3% in obese women (BMI > 30 kg/m2), with average BMI (mean) being 37.3 kg/m2.

Diagnoses included unexplained, male factor and ovulatory dysfunction, with anovulation the most common diagnosis amongst obese women.

Treatment types:
14% natural cycle IUI cycles
61% oral ovulation induction cycles
23% injectable ovulation induction cycles
Treatment type varied (significantly) between BMI classes, with obese women more often requiring gonadotropins to achieve ovulation induction.

Outcomes:
There was no difference in rates of clinical pregnancy, multiple gestation, or multiple delivery for women with obesity compared to women with normal BMI.
When miscarriage, ectopic pregnancy, and biochemical pregnancy rates were analyzed separately, biochemical pregnancy was found to be more likely in women with BMI > 30 kg/m2 than in women in the normal BMI range

Take home points:
While obesity appears too play a larger role in IVF success, IUI success rates appear to be similar (with exception of biochemical pregnancy rates) across normal, overweight and obese women.”  

This post and all posts are for educational purposes only!