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Surrogate and Egg Donor Body Mass Index (BMI)

Marketing Team

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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 our requirements are able to conceive naturally and carry a healthy pregnancy. When it comes to a surrogacy or egg donation 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 (Body Mass Index).


BMI is calculated using a formula that divides an individual’s weight by their height to provide an indicator of body mass.



How to calculate your BMI (infographic)

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 is not an indication of how healthy you are, as you could have a BMI above the requirements to be a surrogate or egg donor and be perfectly healthy!


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

The process of getting pregnant naturally is very different than an IVF pregnancy. When becoming a gestational surrogate, a created embryo is implanted in the uterus and fertility medications are used to aid in the implantation of the embryos. The medications used in this process work optimally with women within a specific body mass index range. Health Magazine recently published and article explaining why BMI may impact IVF success and the role that weight plays in IVF pregnancy.


A surrogate must have an acceptable BMI according to clinic guidelines. In most cases, a surrogate must have a BMI of no higher than 33. If your BMI is too low, you may also not be able to be considered for surrogacy, since women with a BMI less than 19 can take up to four times longer to conceive.


When it comes to surrogacy, taking a longer time to have a successful transfer means time, money, and emotional expenditure for both the intended parents and surrogates. To illustrate this point, a study published in August 2018 in the Journal of Assisted Reproduction and Genetics found that women with a BMI above the normal range had a higher risk for IVF cycle cancellation and lower rates of ongoing pregnancy.


Screening gestational carriers for acceptable BMIs can help to avoid any potential complications with the in-vitro fertilization (IVF) process and ensure that the surrogate's body is as ready as possible to respond to IVF medications. Our goal is to create the safest scenario for our surrogates and the highest rate of a successful outcome for our intended parents.



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).


Many surrogate and egg donor applicants don’t qualify because of their BMI. Learn about other surrogate requirements and egg donor requirements in 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!


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