March 6, 2001 -- Women who work outside their homes late into their pregnancies have higher blood pressures on the days they clock in than on the days they stay home. The increase in blood pressure was small but significant, according to Australian research published in the March issue of the medical journal Obstetrics and Gynecology.
To arrive at their conclusion, researchers measured the blood pressures of 100 pregnant working women while on the job, right after work, at sleep, and over the entire 24 hours of a workday. They then compared these readings to those taken on a non-workday. In addition to a general rise in blood pressure on workdays, they noted that the bigger the gain, the more chance the woman had to become hypertensive -- that is, to go on to develop chronic high blood pressure.
"We observed significant differences in the magnitude of [blood pressure] increases between work and non-workdays in women who developed pregnancy hypertension," the authors write. "... Analysis found that this change in [blood pressure] was a significant predictor of subsequent pregnancy hypertension."
The authors say their results ought to be confirmed by additional research -- but they point out that other studies already have shown that working pregnant women are at higher risk for developing preeclampsia, a condition characterized by high blood pressure, protein in the urine, and swelling.
"Preeclampsia used to be called toxemia," says William M. Manger, MD, PhD, chairman of the National Hypertension Association. "It occurs in 3% of all pregnancies."
First-time pregnant women are most at risk of developing preeclampsia -- at either end of the age spectrum, from young teens to those in their 40s -- as are women with a personal or family history of preeclampsia, those carrying multiple fetuses, diabetics, and women with a history of chronic high blood pressure.
The great danger is that preeclampsia, untreated, will become full-blown eclampsia.
"That's serious because it can cause the death of the patient," Manger says. "[Eclampsia is characterized by] pronounced hypertension, headache, abdominal pain, seizures, and [in some cases] the death of mother and fetus. It's a very severe condition."
While the changes in blood pressure related to working may seem small, they might prompt some women to reconsider whether to continue working into the third trimester -- that is, if they have the luxury of considering such an option.
Cindia Cameron, organizing director for group 9to5 National Association of Working Women, says employers can, by their actions, sometimes force a woman to choose between her health and a paycheck. While all employers with a certain number of employees are required to offer unpaid maternity leave, usually 12 weeks, there's nothing saying they can't start the clock early and require her to return immediately after delivery, she points out.
"The law is the basic minimum," she says. "Many employers do offer more. But after that 12th week, they can replace you."
Cameron suggests women be prepared to negotiate.
"There are many things women could propose: half-time work, working from home. Do a job share. Do light duty. And an employer might [go for it], but they don't have to," she says. Indeed, the light duty question is one that comes up often at 9to5, but as Cameron points out, no company has to offer light duty unless an employee has been injured on the job.
Before approaching your employer, Cameron suggests thinking about what leverage you have.
"You have to convince the employer to do the humane thing," she says. "Find out from their point of view why what you're asking for is a good idea."
And above all, talk with your doctor about whether or not you should continue working. He or she might consider you to be at risk for complications and may sign a note so that you can take breaks during the day, be assigned a different job temporarily, or take extra time off work.