Much like a piece of ripe fruit, a human embryo has a certain squishiness that could provide fertility clinic staff with clues about its viability, a new study finds. ... More than 5 million babies have been born through in vitro fertilization, but the process of selecting viable embryos is still far from perfect.

What are the chances of an embryo surviving?

The survival rate was 69% for thawed zygotes, 85% for D3 embryos, and 88% for blastocysts [Table 1]. The implantation rate per number thawed was 10% for zygotes, 12% for D3 embryos, and 14% for blastocysts.

Why is an embryo not viable?

Causes of a Nonviable Pregnancy

The most common reasons for this include: A baby born too prematurely to be able to survive (before 23 weeks) A congenital defect that makes the survival of the fetus outside of the uterus impossible. A pregnancy in which the fetus no longer has a heartbeat.