A 2025 study found that 0PN zygotes can actually be normally fertilized but missed during the standard 16–18 hour fertilization check, while those that never form pronuclei are likely unfertilized eggs, supporting a slightly earlier check around 16–17 hours and continued culture of 0PNs to the blastocyst stage for confirmation of fertilization.
The Italian Society of Fertility and Sterility and Reproductive Medicine (SIFES-MR) has issued new guidelines on 28 IVF add-ons, outlining which may help in certain situations, which lack evidence, and which should be limited to research.
Researchers in a 2023 study review the use of 27 IVF add-ons and provide recommendations by ESHRE, with only several that are recommended or could be considered for the general infertility population.
