edWire News: Women who stand for long periods while they are pregnant risk hampering the growth of their developing fetus, researchers say in Occupational and Environmental Medicine .
Contrary to previous studies, Alex Burdorf (Erasmus University, Rotterdam, the Netherlands) and colleagues found that pregnant women who did physically demanding work or had long working hours were not at an increased risk for giving birth to a small for gestational age, low birthweight, or preterm baby.
However, women who reported standing for long periods of time often during their pregnancy were more likely than women who did not to have fetuses with a head circumference that was 1 cm smaller than the average at birth.
Compared with women who worked less than 25 hours per week, those who worked 25‑39 hours per week and more than 40 hours per week were significantly more likely to have fetuses that were 1 cm smaller in head circumference and weighed 148‑198 g less than average at birth. The differences were apparent from the third trimester onwards.
Burdorf et al emphasize that these findings were not reflected in adverse birth outcomes.
They say that physically demanding work, long working hours, and working at up to 34 or 36 weeks of pregnancy also had no adverse impact on fetal development.
The authors remark that, generally, women who work while they are pregnant have fewer complications, birth defects, and stillbirths than women who are unemployed, but add that certain aspects of work may be associated with risk.
The researchers assessed the fetal growth rates of 4680 pregnant women between 2002 and 2006. These women completed a questionnaire during mid-pregnancy about whether their paid employment involved lifting, long periods of standing, night shifts, and long working hours.
“We believe that optimizing the work environment is important since participation of women in the reproductive age in the workforce continues to increase,” comment Burdorf and team.
“Preventive measures reducing certain occupational conditions, such as shift work, night hours, standing, lifting and noise, have proven to reduce the risks of adverse birth outcomes.”
By Piriya Mahendra