Why is endometrial integrity important in female fertility?

• A. It ensures the uterus can develop and sustain a pregnancy
• B. It regulates ovulation
• C. It stimulates cervical mucus production
• D. It determines embryo genetics

Answer: (A)

The key idea is that the endometrium must be receptive and able to support implantation and early pregnancy. Each cycle the lining thickens under estrogen and becomes a secretory, gland-rich tissue under progesterone, undergoing decidualization to create a nourishing, blood-rich environment. This environment provides the necessary nutrients, blood supply, and immune tolerance for the embryo to implant and begin growing, before the placenta takes over. If the endometrium is damaged, too thin, or not properly prepared, implantation may fail or pregnancy may not be sustained, leading to infertility or early pregnancy loss.

The other options don’t fit this concept: regulating ovulation is controlled by the hypothalamic-pituitary-ovarian axis; cervical mucus production is mainly influenced by estrogen and occurs in the cervix; embryo genetics are determined at fertilization by the genetic material from the egg and sperm, not by the endometrial lining.