No potential link between Night Shifts during pregnancy and risk of having small for gestational age babies: BMJ

A recent study published in BMJ Occupational and Environmental Medicine found no potential link between night work during pregnancy and the risk of having a small for gestational age (SGA) child. The study analyzed data from 2007 to 2015 primarily focused on healthcare employees, such as nurses and medical doctors.

The research, based on detailed payroll information obtained from the Danish Working Hour Database, identified 24,548 singleton pregnancies involving 19,107 women. The investigation aimed to determine whether the intensity and duration of night work during the first 32 weeks of pregnancy had any bearing on the likelihood of delivering an SGA child.

None of the dimensions of night work, whether in terms of intensity or duration, were found to be associated with an increased risk of SGA. Interestingly, there was a noteworthy observation: a slight increase in the risk of SGA was identified in pregnancies where women ceased working night shifts during their pregnancy. This finding opens up intriguing avenues for further research into the dynamics of night work during pregnancy.

The study's comprehensive approach included adjusting for variables such as age, body mass index, socioeconomic status, and smoking, aiming to account for potential confounding factors. In addition, the researchers employed quantitative bias analysis and G-estimation to explore the possibility of a healthy worker survivor bias (HWSB).

Notably, G-estimation suggested that if all workers continued to work night shifts throughout their pregnancies, as opposed to exclusively daytime work, there could be a reduced odds ratio (OR) for the association between night work and SGA. This finding hints at a complex interplay between work schedules and pregnancy outcomes that warrants further investigation.

This study brings reassuring news for healthcare workers who engage in night shifts during their pregnancies. It found no increased risk of delivering small for gestational age babies, a condition associated with various health concerns. Further research may shed more light on the subtle relationships between work schedules and pregnancy outcomes. 

Source:

Begtrup, L. M., Sejbaek, C. S., Flachs, E. M., Garde, A. H., Specht, I. O., Hansen, J., Kolstad, H. A., Bonde, J. P. E., & Hammer, P. E. C. (2023). Night work during pregnancy and small for gestational age: a Danish nationwide register-based cohort study. In Occupational and Environmental Medicine (p. oemed-2023-108981). BMJ. https://doi.org/10.1136/oemed-2023-108981