Transferring a good and poor quality embryo together: a meta-analysis

Researchers in a 2022 study performed a meta-analysis to combine the results of studies examining the transfer of a good and poor quality embryo together (vs one good quality embryo alone), and found no differences in pregnancy or live birth rates, but increases in the rate of multiples.

why do embryos fail to implant or miscarry?

This post covers the variety of reasons embryos can fail to implant or miscarry, including as a result of advanced maternal age, chromosomal translocations, lifestyle, endometritis, the microbiota, immunological issues, endometrial receptivity, the clinic, and more. Note that this is not a complete list, and will be updated periodically.