My husband and I have been trying to conceive for two years. I have charted my basal body temperature and know when I ovulate, and we have sex accordingly. Years ago, when I worked for a dentist, I would practice taking X-rays on myself. At that time I had no desire to have children, and I didn't bother wearing the lead apron. Could this have made me infertile? If so, is there some way a doctor can tell for sure?

-- Kathy

It would be highly unlikely that exposure to dental X-rays resulted in any significant exposure to the ovaries. Your doctor can check this by measuring a day 3 FSH blood level or performing a clomiphene challenge test (CCT) to determine ovarian reserve.

Charting your basal body temperature is helpful in determining whether you ovulate or not, but it is inherently unreliable in predicting when you ovulate. The error in predicting the day of ovulation is plus or minus four days. If you wish to determine when to attempt conception, you are much better off using a urinary LH test, which accurately predicts the day of ovulation in up to 85 percent of women.