The thickness is just one of the factors to consider. The presence of the "three-line sign," blood flow, and endometrial receptivity testing (ERA) are also crucial. It's easy to misjudge the situation based solely on one parameter.

In clinical practice, a thickness of 8–14 mm is generally considered ideal. However, some women have successfully conceived even with a thickness of 7 mm, while others failed despite having a thickness of 15 mm or more. This shows that thickness isn't the only variable to consider.

A more comprehensive assessment involves four aspects:

First, the shape of the endometrium. A clear "three-line sign" (a high-echo line in the center and low-echo bands on both sides) after ovulation or when medication is used usually indicates that the endometrium is in a acceptable state.

Second, blood flow. Abundant blood flow beneath the endometrium provides a better indication of endometrial receptivity compared to just the thickness of the endometrium.

Third, endometrial motility and peristaltic waves. Excessive peristalsis on the day of transplantation might affect embryo positioning.

Fourth, previous cycle conditions. If similar thickness levels led to failures in previous cycles, it's worth conducting a more thorough evaluation.

If the thickness consistently falls below acceptable levels, common approaches include adjusting the method of estrogen administration (from oral to vaginal or transcutaneous), improving blood flow, performing hysteroscopy to check for adhesions or chronic endometritis, and implementing individualized endometrial preparation plans.

The key is to ask clearly before transplantation: "What about the shape and blood flow of my endometrium, aside from its thickness?" Instead of focusing solely on the thickness of 7 mm.