Reproductive outcomes among hairdressers

The present study aimed at examining the possible risk of working as a hairdresser during pregnancy in relation to reproductive outcomes.

The Swedish Medical Birth Register, which includes almost every infant born in Sweden, has, since 1983, collected information prospectively about occupation in early pregnancy. This information is given at the first visit to a prenatal center. During the period 1983-2001, 12 046 infants were born to female hairdressers working either full- or part-time during early pregnancy. For comparison, all other deliveries during the same period were used in which the mother had worked either part-time or full-time.

The full-time hairdressers more often had intrauterine growth-retarded infants (ie, small for gestational age) as compared with referents with a corresponding worktime [adjusted odds ratio (OR) 1.20, 95% confidence interval (95% CI) 1.06-1.36]. The pattern was similar for part-time hairdressers (adjusted OR 1.16, 95% 0.93-1.46). The fraction of malformations did not differ from those among the referents. The gender ratio for the infants of hairdressers was similar to that for the overall Swedish population.

The findings concerning infants small for their gestational age in the present study is in accordance with previous findings. The reason for these findings remains unknown. Studies with more-specific exposure information during pregnancy are needed.