There is some connection between flying frequently as flight attendant and miscarriages
Recent studies have shown a slightly increased risk of miscarriage among flight attendants, possibly due to cosmic radiation, work during sleep hours, and high physical job demands. However, miscarriage risk was not increased among flight attendants compared with teachers.
Spontaneous abortion or miscarriage is a very common problem regardless of occupation or activity. In the first month of pregnancy about half of the fertilized eggs do not survive, most because of lethal chromosome abnormalities. Once a woman misses her period and knows she is pregnant, 15% of the embryos miscarry naturally.
There are about 24 known medical problems that are responsible for pregnancy losses. Smoking and drinking increase the risk, as does thyroid disease and diabetes. The radiation exposures in flight are too low to contribute to the risk of abortion and the oxygen levels in a pressurized cabin are more than adequate for the mother and fetus.
Stress may be a factor, but it will vary with the individual. Studies performed in female flight attendants, show that miscarriage risk was not increased among flight attendants compared with teachers.