At Circle, one question that always comes up is: “Why is surrogate BMI so important?”
Your BMI is calculated using a formula that divides an individual’s weight by their height to provide an indicator of body mass.
You can find your own value by calculating your BMI. In the general healthcare setting, it’s often used to screen for weight categories that may lead to health problems, such as diabetes. In assisted reproduction, it’s used to qualify surrogate and egg donor applicants.
BMI requirements differ for surrogates and egg donors. However, weight plays a big role in both processes. Let’s start with surrogacy.
A surrogate must have a BMI of 33 or below, and in some cases can have a BMI of up to 35. Class II Obesity, a BMI above 35, can increase the time to conception two-fold. Additionally, underweight women with a BMI less than 19 can take up to four times longer to conceive.
When it comes to surrogacy, an extended time to conception means time, money, and emotional expenditure for both the intended parents and surrogates. Screening gestational carriers for BMI’s under 33 can help to avoid any potential complications with the in-vitro fertilization process.
Egg Donor’s BMI
BMI requirements are a bit different for egg donors. The required BMI for donors is under 28. A higher BMI may affect egg quality as well as necessitate higher doses of stimulation drugs to create follicles. More medications can lead to additional costs for the intended parent(s).
Some statistics from a paper published in the Journal of Fertility and Sterility:
- Patients with a BMI equal to or greater than 30 had significantly decreased odds of implantation, clinical pregnancy, and live birth.
- Compared with normal BMI, the adjusted odds of live birth are decreased by 37 percent in class I obesity, 61 percent in class II obesity, and 68 percent in class III obesity.
- Obese patients required higher daily doses of fertility drugs and had lower peak Estradiol levels.
- The chances of cycle cancellation, spontaneous miscarriage, ectopic pregnancy, or multiple births were not significantly different.
Many surrogate and egg donor applicants don’t qualify because of their BMI. Luckily, you can always start a weight loss program and reapply when your BMI is within the required range.