Lab conditions
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.
Embryo arrest is when an embryo stops developing, usually before reaching the blastocyst stage. This post explains possible causes, including embryonic genome activation, maternal effect genes, the subcortical maternal complex, aneuploidy, mitochondrial dysfunction, oxidative stress, lab conditions, and sperm DNA fragmentation.