Years ago, in my mid-20s, I learned from an ultrasound that I was born with one fallopian tube, one ovary and a uterus of half the normal size. At the time I was not terribly concerned because I thought I didn't want to have children. Now, 12 years later and married, at age 37, I would like to know if I can carry baby to term, assuming I am not too old to conceive. If so, what risks do I face?

Lori

As I described in an earlier column about Uterine Septum, the uterus and fallopian tubes form in a developing baby from two separate ducts, which fuse together in the middle to create the uterus. Many things can go wrong during this complex process. When only one of original ducts develops, the result is a unicornuate uterus -- a uterus of half the normal size, with one fallopian tube. However, development of the ovary is determined separately, and usually both ovaries are present in women with this anomaly. A CT scan of the pelvis or a transvaginal ultrasound may well show that your ovary is in fact present.

The presence of the second ovary is an issue in predicting how long it may take for you to conceive. In general, women with a unicornuate uterus do not have a significantly lower pregnancy rate. However, if both ovaries are present, pregnancy will be unlikely in the months when ovulation occurs on the side that has no corresponding tube. If you do not have the second ovary, this is not an issue; your one ovary should produce an egg each month.

Once you do conceive, the pregnancy should progress normally, although there is a slight increased risk of early labor. Your physician will probably want to monitor the pregnancy a bit closer with periodic ultrasound examinations to make sure your cervix remains closed.