Working while pregnant more than quadruples risk of pre-eclampsia

Women who work during pregnancy are almost five times as likely to develop pre-eclampsia, concludes research in the Journal of Epidemiology and Community Health.

In pre-eclampsia abnormally high blood pressure, blood poisoning, and swelling develop. Pre-eclampsia can be dangerous for both mother and child.

The blood pressure of 933 women in their early to late 20s was monitored over 24 hours while they went about their daily routines. The women were all between 18 and 24 weeks of pregnancy with their first child. They were divided into three groups: 245 were working during their pregnancy; 289 were not working; and 399 were employed, but chose not to work.

The women who were working had the highest blood pressure readings of the three groups. Older women tended to have higher blood pressures, but there were more smokers among the younger women.

There were no differences among the three groups in length of pregnancy, birthweight, or method of delivery – induction or caesarean section. But women in employment were almost five times as likely to develop pre-eclampsia. This finding was irrespective of factors known to influence blood pressure, such as smoking, drinking, weight, height and age.

The authors did not assess what type of work was particularly associated with pre-eclampsia.

Many women develop high blood pressure during pregnancy, a condition known as pregnancy hypertension, but there is usually very little risk to mother or child, say the authors, and the condition resolves after birth. It does not automatically predispose a pregnant woman to developing pre-eclampsia.

There is no obvious explanation for the link between pre-eclampsia and work, say the authors, but it has been suggested that the stress of work may increase the amount of circulating stress hormones. This affects the sympathetic nervous system, which then increases blood pressure levels.