At EFC, our live birth rate from vitrified eggs is over 40% per embryo transfer. This rate is among the highest in the country. Our results are regularly submitted for peer-reviewed publications and have been awarded research prizes at major scientific conferences.
The following should be considered when comparing the success rates of fertility centers offering egg freezing services:
Is the success rate a clinical pregnancy rate or a live birth rate?
Clinical pregnancies are early pregnancies that can be miscarried at a rate of 15% or more. The live birth rate is defined as the birth of at least one live infant—the desired goal of egg freezing—and is not subject to miscarriage adjustment. Thus the live birth rate per embryo transfer is the most meaningful rate of comparison.
Are the success rates per patient or per embryo transfer?
If an individual patient undergoes multiple embryo transfer procedures, she is more likely to get pregnant over time. However, each embryo transfer requires a batch of frozen eggs. To properly plan the number of eggs to freeze, you should know the pregnancy rate per embryo transfer and not the pregnancy rate per patient, which actually represents the cumulative rate based on multiple transfers.
How many embryos are being transferred per pregnancy attempt?
The more embryos transferred, the higher the chance of pregnancy. However, transferring an excessively high number of embryos (more than four) can also lead to triplets and quadruplets, which are considered high-risk pregnancies. Most leading centers in the field transfer an average of 2-3 embryos per procedure.
Are the reported pregnancy rates derived from frozen donor eggs or from the patient’s own eggs?
Pregnancy rates from donor eggs represent the highest possible rates, because the eggs come from women in their twenties. Reporting pregnancy rates based on egg donors falsely overestimates the rates of women in their thirties or forties using their own eggs.
How many eggs were thawed per embryo transfer?
Thawing 6-10 eggs should yield sufficient embryos for a single embryo transfer. Thawing an excessive number of eggs falsely bolsters pregnancy rates and leads to egg and embryo wastage.
Be informed about success rates. Ask the right questions.