I am a 23-year-old woman. I was diagnosed with Turner syndrome. When I was 11 years old, I recall having one period for a week. Other than that, I have never had a menstrual cycle. Can I still get pregnant? If I want to conceive, what do I need to do?

S.E.

Turner syndrome is due to a chromosomal anomaly described as 45X, in which the woman's cells have only 45 chromosomes instead of the normal 46; they are missing the second X chromosome. In these women, the ovaries do not form normally.

A small percentage of women with this condition demonstrate chromosomal mosaicism. This usually means that some of their cells are 45X, while other cells may contain 46XX, the normal chromosomal makeup. These women may undergo a normal puberty and even experience a few normal menstrual periods. But in a very short while, the eggs seem to be exhausted, and premature menopause results.

It is important to test your chromosomal pattern, as some cases of mosaicism contain both 45X and 46XY. Women whose chromosomal analysis reveals a Y chromosome in some of the cells are at risk for the development of ovarian tumors. These tumors can produce estrogen and stimulate pubertal development. If cells with Y chromosomes are evident, laparoscopy should be performed and any ovarian tissue should be removed.

Luckily, ovarian tumors resulting from this condition are rare. However, natural pregnancy is even rarer. In order to conceive, you will probably need to use an egg donor. The good news is that if you get proper treatment and supervision, this condition should not affect your ability to carry the pregnancy, nor pose other risks to the fetus during the pregnancy.