The Importance of Body Mass Index (BMI)

In order to be considered for surrogacy or egg donation, applicants have to meet certain qualifications. One such requirement is Body Mass Index (BMI). Curious as to why it’s so important? Then read on!

BMI For those of you unfamiliar with the term, BMI is a number calculated from a person’s weight and height, providing a reliable indicator of body fat for most people. In general healthcare, 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.

Surrogate’s BMI
A surrogate must have a BMI of 32 or below. Obesity, a BMI above 35, increases the time to conception two-fold. Additionally, underweight women with a BMI less than 19 take four times longer to conceive! When it comes to surrogacy, this means time, money, and physical and mental exhaustion for both the intended parents and surrogate. Ensuring a gestational carrier is at a healthy weight helps to avoid any potential complications.

Egg Donor’s BMI
The story is a bit different for an egg donor. The required BMI for donors is under 28. Egg donors are required to be of proportionate height and weight, as being overweight may affect egg quality, as well as necessitate higher doses of stimulation drugs to create follicles. More medications lead to additional costs for the intended parent(s).

Some Statistics from a recent paper published in 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 1 obesity, 61 percent in class 2 obesity, and 68 percent in class 3 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.