Álvarez M, Gaggiotti-Marre S, Martínez F, et al. - Researchers aimed at determining if pregnancy outcomes can be improved by an individualised luteal phase support (iLPS), according to serum progesterone (P4) level the day prior to euploid frozen embryo transfer (FET), when initiated on the day previous to embryo transfer. They performed a prospective observational study of patients undergoing preimplantation genetic testing (PGT) for aneuploidies (PGT-A) IVF cycles and a subsequent FET under hormone replacement treatment. Analysis was performed on a total of 574 cycles (453 patients): 348 cycles (leading to 342 euploid FET) with adequate P4 on the day prior to FET, and 226 cycles (leading to 220 euploid FET) under iLPS after low P4 on the previous day to FET, but restored P4 levels on the transfer day. Overall outcomes suggest that the addition of daily subcutaneous P4 injections (Psc) can benefit patients with low serum P4 the day prior to euploid FET, when it is initiated the day prior to FET, and results in achievement of reproductive outcomes similar to those with initial adequate P4 levels.