Endometrial growth is divided in two phases depending on the moment of the menstrual cycle:
- starts on day 1 of the cycle until day 14, when ovulation occurs. It a estrogen-dependent phase.
- starts after ovulation, on day 15, and extends until the end of the cycle. Progesterone plays a major role at this stage. Implantation is more likely to take place on days 19-21. This period is known as implantation window.
By Mark P. Trolice MD, FACOG, FACS, FACE (reproductive endocrinologist), Miguel Dolz Arroyo MD, PhD (gynecologist), Rebeca Reus BSc, MSc (embryologist) and Sandra Fernández BA, MA (fertility counselor).
Last Update: 10/11/2018