A pilot study indicates that pregnant women in high-stress jobs secrete elevated amounts of catecholamines, the socalled "fight-or-flight" hormones. Some scientists suspect that elevated blood levels of these hormones can sometimes trigger premature labor and early delivery of very small babies, who risk breathing troubles and other serious health problems.
The new report may help explain previous findings linking stressful jobs with an increased threat of premature labor and delivery of low-birthweight babies. Experiments with pregnant animals have shown that elevated catecholamine levels can decrease blood flow to the uterus, in some cases leading to premature labor.
Obstetrician Vern L. Katz noticed among his patients that pregnant physicians with demanding work schedules seemed to deliver prematurely more often than women in less stressful jobs. That observation prompted Katz and his colleagues at the University of North Carolina in Chapel Hill to explore the connection between catecholamines and stress in a study of 10 physicians and three intensive-care-unit nurses, all in their third trimester of pregnancy. The 13 women had jobs requiring long and irregular shifts, prolonged periods of standing, and mentally taxing duties such as decisions about patient care.
The researchers instructed the women to collect urine samples during a typical workday and again, about a week later, on a non-workday. In analyzing the urine samples, the team discovered that catecholamine levels averaged 58 percent higher on workdays than on non-workdays.
They went on to compare these levels with those of a control group of 12 women in their third trimester os pregnancy who worked in lower-stress jobs. The 12 women collected urine during a typical workday, and again the team analyzed the samples for catecholamines.
In the March Obstetrics …