Some of the most common factors that can influence uterus lining thickness include hormonal imbalances and abnormally short menstrual cycles. A woman may also experience problems with the thickness of her uterine lining because of fertility drugs she is taking or impaired blood supply to the uterus. Conditions that directly affect this reproductive organ as well as infections and scarring may play a role as well.
Among the most common problems that affect the uterus lining thickness are those that involve hormones. For reproductive health, a woman's hormones must typically stay in good balance. A woman's uterine lining may be adversely affected when levels of estrogen in her body are too low, and the hormone progesterone may affect the lining as well. For example, if a person has too little progesterone in her body, it is possible for her to develop a condition called endometrial hyperplasia, which is marked by the over-thickening of the uterine lining. Too little progesterone may also cause a woman's lining to shed too soon during her menstrual cycle.
Another issue that may affect uterus lining thickness is abnormal menstrual bleeding. When a woman's menstrual cycle is abnormally short or she experiences abnormal bleeding throughout her cycle, the lining may never grow as thick as expected. This is particularly important when a woman is trying to conceive, as a reasonably thick lining is critical for the successful implantation of a fertilized egg.
Insufficient blood flow to the uterus may also adversely affect a woman's uterus lining thickness. There are various issues that can impair blood flow to this organ. Among the most common are high blood pressure (which is also referred to as hypertension), blood clotting disorders, and sometimes a condition called polycystic ovary syndrome, which is marked by multiple ovarian cysts.
Sometimes the medications a woman uses to increase her chances of conceiving also may interfere with the thickening of the uterine lining. For example, some fertility drugs alter the processes the body goes through to produce hormones and prepare for possible pregnancy. As such, some of these drugs thin the uterine lining. This may be corrected, in some cases, by taking a different drug, by discontinuing their use, or by supplementing with extra estrogen.
Anything that adversely affects the uterus may contribute to changes in uterine lining thickness. For example, a person may have a thinned uterine lining as the result of a surgery on the uterus or a uterine infection. Scarring of the uterus may cause this issue as well.