
Device May Aid Pregnancy MonitoringBy
Marcia Wood June
19, 1998An expectant mother's chances of delivering a healthy, normal-weight baby
may increase in the future. That's thanks to a promising new technique for
monitoring the pregnancy. Called bioimpedance spectroscopy, the technique may allow fast, convenient
and painless measurements of water-weight gains during pregnancy. Scientists
with the Agricultural Research Service,
the University of California at Berkeley, and Xitron Technologies, Inc., San
Diego, Calif., showed that bioimpedance measurements correlate significantly
with infant birth weight. The researchers measured water-weight gain of 10
women before pregnancy, at intervals throughout pregnancy, and after delivery. With further study, bioimpedance spectroscopy may augment ultrasound
monitoring, according to ARS research physiologist Marta D. Van Loan at the
Western Human Nutrition Research Center,
San Francisco. Van Loan led the bioimpedance monitoring. Low-birth weight babies--those weighing less than five and one-half pounds
at birth--have an even greater risk of early health complications than premature
babies. An expectant mother who does not eat properly, exercises too
vigorously, takes diuretics or abuses drugs, for example, may deliver an
underweight infant. Physicians have known for more than four decades that moderate water
accumulation during pregnancy is a strong indicator of proper fetal growth. The
ARS-led investigation, however, was likely the first to show that bioimpedance
spectroscopy may offer an safe, accurate and inexpensive way for physicians to
detect subnormal water-weight gains in time to help their patients take
corrective action. Bioimpedance measurements take less than two minutes to perform. They
involve sending a harmless current between electrodes positioned on the hand and
foot. A personal computer linked to the bioimpedance spectrometer processes
these measurements. It then prints out an estimate of the patient's water load,
called "total body water." Scientific contact: Marta D. Van Loan, USDA-ARS
Western Human Nutrition Research Center,
P.O. Box 29997, Presidio of San Francisco, CA 94129, phone (415) 556-5729, fax
(415) 556-1432, [email protected]. Story contacts Western Human Nutrition Research Center Marcia A Wood U.S. Department of Agriculture | |