I'm 29 years old and the mother of two. My periods are regular, but they are always four months apart. I've had a tubal ligation, so pregnancy is not an issue. Should I be concerned about the long space between periods?

--Marie

Long stretches between periods are a sign of not ovulating, and although this is not an issue from the standpoint that you are not planning on having any more children, it is of concern. Some women do not ovulate and do not have monthly periods because of thyroid imbalance; an underactive thyroid increases the risk of cardiovascular disease, while an overactive one predisposes to osteoporosis. If you are skipping periods because you are too thin or exercise too vigorously, this also places you at significant risk for osteoporosis because your estrogen levels are too low. If you are missing periods because you are obese and, therefore, have a chronically elevated estrogen level, this increases your risk of developing cancer of the uterine lining. If you have polycystic ovarian syndrome, then your risk of diabetes as well as uterine cancer is increased.

In other words, there are many possible reasons for having a period only every four months. The bottom line is that this is NOT normal and really should be investigated. You should see your gynecologist for a complete physical. Your doctor may want to order a few blood tests and may recommend an endometrial biopsy (a sampling of the uterine lining tissue) as well.