What percentage of blastocysts fail to implant in the uterine wall?

1. Implantation requires the endometrium to be properly developed and receptive to the blastocyst. 2. If the endometrium is not ready, the blastocyst detaches, and often does not find a suitable spot at all. 3. The failure rate for implantation directly. 4. Less than 5 percent and About 20 percent are both different figures a reader might guess from memory, but neither matches the specific figure given here. 5. Nearly 100 percent is also incorrect for the same reason: it does not match the specific figure given here. 6. That rate is 50 to 75 percent, which is why pregnancy often requires several ovulation cycles to achieve. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 28 "Development and Inheritance", p.1327 §Implantation_