April 17, 2002 -- Women who work during pregnancy may be at increased risk for high blood pressure and a potentially serious related condition. In a study from Ireland, those who held jobs outside the home late in their second trimesters were almost five times more likely to develop preeclampsia than those who did not work.
Researchers say the findings are preliminary, and that the risks of working are small for the vast majority of pregnant women. The main message, they add, is that more study is needed to better understand just what those risks are.
"Certainly the trend here and in the U.S. has been that most women work, and they work later and later in their pregnancies," says lead author and ob-gyn John R. Higgins, MD, of Ireland's University College Cork. "It is politically incorrect to suggest that this might not be a good thing, and we certainly aren't saying that based on these data. But this needs further study. Even if the risks are small on an individual basis, they may be significant to the population as a whole."
Also known as toxemia or pregnancy-induced hypertension, preeclampsia occurs in 5-10% of pregnancies and can endanger the health of both the mother and her baby. While at least one previous study has suggested that working outside the home is a risk factor for high blood pressure and preeclampsia, a definitive link has not been established.
In this study, reported in the latest issue of the Journal of Epidemiology and Community Health, Higgins and colleagues evaluated nearly 1,000 healthy women between 18 and 24 weeks of pregnancy. All were expecting their first babies and none had a history of high blood pressure. Blood pressure was measured with a device that is worn for 24 hours and gives readings throughout the day. Overall, 245 women worked during the monitoring day, another group of almost 400 working women stayed home during the monitoring day, and a third group of nearly 300 women did not work outside the home.
After adjusting for other risk factors, it was determined that the women who worked on the monitoring day had significantly higher blood pressure readings than those who did not, and they were almost five times more likely to develop preeclampsia. There were no significant blood pressure differences between the women without jobs outside the home and those who did not work on the monitoring day.
Higgins says future studies should include women in their third trimesters and those who already have children.
"We don't know if there is a difference between women working outside the home and those already raising children," he tells WebMD. "It could be that the stresses and pressures are the same."
High blood pressure expert Phyllis August, MD, says pregnant women who are at risk for high blood pressure or preeclampsia need to do all they can to reduce stress. For many, that may mean putting work on hold. August is chief of New York Hospital-Cornell Medical Center's division of hypertension.
"Telling the average woman who does not have [high blood pressure] or a history of [high blood pressure] to stop working would certainly be inappropriate," she tells WebMD. "But I tell my patients who are at high risk not to work. If a woman is at risk for preeclampsia, she needs to take it easy and get as much rest as possible."