Objectives This study assessed the occurrence of perinatal death, low birthweight, preterm birth, and birth defects (total, major, neural tube defects, total cleft, cleft palate, hypospadias, and Down syndrome) in the offspring of airline pilots and cabin attendants.
Methods A cohort of offspring of airline pilots and cabin attendants was established and characterized in terms of parental exposure to cosmic radiation the year before birth or ever. Pregnancy outcome was derived from the Medical Birth Register of Norway. The reference group comprised offspring of parents without occupational exposure to cosmic radiation.

Results No deviant risks were observed for the offspring of male pilots, either for the year preceding birth (N=2111) or ever (N=2356). Specific birth outcomes were fewer for the pilots than for the referents (N=1 621 186), except for Down syndrome, which was more frequent [odds ratio (OR) 1.41, 95% confidence interval (95% CI) 0.53-3.76]. For exposure the year preceding birth (N=2512), the risk of low birthweight was lower for the female cabin attendants than for the referents (adjusted OR 0.83, 95% CI 0.69-1.00), while Down syndrome was more frequent (OR 1.44, 95% CI 0.60-3.47). For exposure ever (N=3346), the risk of low birthweight was lower (OR 0.82, 95% CI 0.70-0.96) for the cabin attendants, while hypospadias (OR 1.18, 95% CI 0.61-3.04) and Down syndrome (OR 1.79, 95% CI 0.03-3.45) were more frequent.

Conclusions In general, offspring of air pilots and cabin attendants do not seem to be at increased risk of adverse pregnancy outcome.

Key terms airline pilot; aviation; birth defect; birthweight; cabin attendant; cosmic radiation; epidemiology; malformation; offspring; perinatal death; pregnancy outcome; preterm birth