Physically Demanding Work May Lead to Pregnancy Problems
April 5, 2000 (Atlanta) -- Physically taxing work conditions -- like
prolonged standing, heavy lifting, and night work -- may increase a woman's
risk of having a problem pregnancy, say researchers who reviewed many studies
of the issue.
The risks of such work, the researchers found, include premature babies,
babies that are small for their gestational age, and high blood pressure in the
The researchers, who reviewed 29 studies of the issue involving more than
160,000 working women, say their findings lend support to the need for an
improved national maternity leave policy -- one that includes pay, health
benefits, and job security for all.
"Preterm birth is a huge problem," study author Ellen Mozurkewich,
MD, tells WebMD. "There have been a lot of advances in obstetrics over the
last 50 years that have drastically reduced maternal death and [injury] ... and
fetal and neonatal death.
"But the big remaining problem is preterm birth. The reason it is such a
large problem is -- even though the risk of death related to premature delivery
has decreased markedly -- there are still major long-term problems that can
result for the children." Mozurkewich is an obstetrician-gynecologist who
is receiving additional training in complicated pregnancies at the University
of Michigan Medical School in Ann Arbor.
Mozurkewich and her colleagues looked at the link between preterm births --
those that occur at 20 to 36 weeks' gestation -- and physically demanding work
(that including heavy or repeated lifting or carrying, manual labor, or
significant exertion); prolonged standing; shift work; and long working
They also looked at the relationship between these conditions and a woman's
risk for having a small baby, or developing high blood pressure or a
pregnancy-related condition known as preeclampsia (high blood pressure,
swelling, and protein in the urine). A woman was considered to have been
exposed to risky work conditions if the conditions lasted at least through the
They found that physically demanding work was associated with having
premature or small babies. It was also linked to high blood pressure or
preeclampsia in some mothers. Other conditions associated with preterm birth
included high levels of work fatigue, prolonged standing, and night work.
Working long hours was not significantly associated with preterm birth,
according to the authors.
Even a relatively small increase in the risk of preterm birth is important,
Mozurkewich says. "There have been a lot of studies looking at possible
ways of preventing preterm birth and, for the most part, they have come up
empty handed," she says. "[Working conditions] may not be the largest
contributor to preterm birth in the United States, but it is another
Because many conditions can lead to premature labor or delivery, poor growth
of the baby before birth, and high blood pressure, a woman should talk with her
obstetrician or pregnancy specialist about whether special precautions may be
needed in her case.
"Our association suggests that modifying these lifestyle factors on the
job may reduce a woman's risk of preterm birth," Mozurkewich tells WebMD.
"But I would emphasize that liberalizing leave policies may be necessary;
it is very difficult for many women to modify activities on the job. It is much
easier said than done."