Surrogate and Egg Donor Body Mass Index (BMI)

understanding surrogacy and BMI young woman doing yoga to improve BMI

At Circle, one question that often comes up is: “Why is surrogate and egg donor BMI so important?” It is actually one of our most asked questions from surrogates and egg donors. In recent years, the conversation around body mass index (BMI) and its accuracy in determining overall health has presented an abundance of new information. We understand that BMI is not a clear indicator of health and that women with a BMI over 32 and under 19 are able to conceive naturally and carry a healthy pregnancy. When it comes to a surrogacy journey, BMI impacts the success of the medications necessary for IVF and the embryo transfer. 

What Is BMI?

In order to be considered for surrogacy or egg donation, applicants have to meet certain qualifications. One such requirement is BMI.

BMI and classification values

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.

Surrogate’s BMI

A surrogate must have a BMI of 32 or below; althought, in some cases she 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 BMIs under 32 can help to avoid any potential complications with the in-vitro fertilization (IVF) process.

Egg Donor’s BMI

BMI requirements are a bit different for egg donors. The required BMI for donors is under 29. 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% in Class I Obesity, 61% in Class II Obesity, and 68% 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. Learn about other surrogate requirements and egg donor requirements separate blog posts.

If you’re interested in learning more about surrogacy and egg donation, you can visit our website and start a chat with us! If you’re an egg donor and you’re feeling ready to apply, you can do so here! If you’re a surrogate and you’re interested in applying and starting the process, you can apply here