A 2025 case report describes two IVF patients who conceived triplets from a single embryo transfer and offers insight into just how rare this is.
Multiple pregnancy
This post explains how embryos can split during IVF, especially at the blastocyst stage. It covers the timing of splitting, the different types of identical twins, the factors that make splitting more likely, and how IVF labs can reduce the risk of twins after single embryo transfer.
Researchers in 2023 provided evidence-based guidelines for deciding how many embryos to transfer, as prepared by ESHRE.
Researchers in a 2021 review combined multiple studies on assisted hatching and found no clear improvement in live birth rates, though clinical pregnancy rates were slightly higher and the chance of multiple pregnancy increased.