During IVF, most patients will create multiple embryos and this will force a decision of how many to transfer at one time. The data tells us that if a patient has two embryos, for instance, her success rate with those two embryos will be the same whether she transfers one embryo at a time (known as elective Single Embryo Transfer, or eSET) or both embryos at once.
This is a point that requires continual highlighting: the decision to transfer embryos one-at-a-time or multiple-at-once does not change the odds the cycle will lead to a live birth.
It does mean the patient having a double embryo transfer may require one fewer transfer to achieve the same result. As a result, that patient may become pregnant a month or two earlier and save roughly $3,000 (the cost of one transfer). This is not to be confused with the cost of a whole new cycle (roughly $20,000).
However, if a woman who transfers two embryos at once does conceive, she is far more likely to carry twins-or-triplets (30%) than if she conceives having transferred one-embryo-at-a-time (1%).
This is an especially big problem because multiple gestation pregnancies raise the risk to both mother and offspring.
For this reason, many don’t believe taking on this level of risk is worth it just to save an additional transfer (at $3,000) and a month or two of time.