Birth weight and fetal growth in infants born to female hairdressers and their sisters
- Division of Occupational and Environmental Medicine, Lund University, University Hospital, SE-221 85 Lund, Sweden
- Dr Anna Axmon, Division of Occupational and Environmental Medicine, Department of Laboratory Medicine, Lund University, University Hospital, SE-221 85 Lund, Sweden; anna.axmon{at}med.lu.se
- Accepted 29 August 2008
- Published Online First 18 November 2008
Abstract
Objectives: To investigate birth weight and fetal growth in female hairdressers, while controlling for intergenerational effects and effects related to childhood exposures.
Methods: A cohort of women who had attended vocational schools for hairdressers were compared to their sisters with respect to birth weight and fetal growth (measured as small for gestational age (SGA) or large for gestational age (LGA), respectively) in their infants. In total, 6223 infants born to 3137 hairdressers and 8388 infants born to 3952 hairdressers’ sisters were studied.
Results: Among the infants born to the hairdressers’ sisters, the distribution of birth weights were wider than that among the infants born to the hairdressers. This was also reflected in that hairdresser cohort affiliation tended to be protective against both SGA (odds ratio 0.80; 95% confidence interval 0.49 to 1.31) and LGA (0.77; 0.54 to 1.09). For LGA, this effect was even more pronounced among women who had actually worked as hairdressers during at least one pregnancy (0.60; 0.39 to 0.92). The infants born to these women also had a significantly lower mean birth weight (3387 g vs 3419 g; p = 0.033).
Conclusions: The results from the present study suggest that infants born to hairdressers have a decreased risk of being LGA. This is most likely not caused by a shift in birth weight distribution or abnormal glucose metabolism.
Footnotes
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Funding: The Swedish council for working life and social research.
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Competing interests: None.
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Ethics approval: The study was performed in accordance with the Declaration of Helsinki and approved by The Lund University ethics committee. All participants provided written informed consent.
