Unemployment Linked With Very Low Birth Weight
Dec. 10, 1999 (Atlanta) -- Unemployment is associated with very low birth
weight (three pounds or less), according to a Scandinavian study in the
December issue of the Journal of Health and Social Behavior. Thus, the
associated, expensive, pre-term deliveries may be preventable to some extent.
In the U.S., very low birth weight infants represent 1% of births and 64% of
"The most important point is that the incidence of very low birth
weight, which clinically is a very significant phenomenon, is not random over
time," lead author Ralph Catalano, MD, tells WebMD. "It's influenced by
factors in the community that are to some degree controllable." Catalano is
professor of public health at the University of California, Berkeley.
Can the findings be generalized to the U.S.? Yes, says Catalano. There is no
biological reason why the phenomenon found in this study should be peculiar to
Scandinavia, he explains. In fact, he adds, the effect may be even stronger in
the U.S. due to fewer support systems for people who are economically insecure
or losing jobs or income.
This study used a test to compare quarterly economic rates of unemployment
among Norwegian and Swedish males with the incidence of very low birth weight
from 1973 through 1995.
Over this time period, quarterly economic rates of unemployment were
associated with an increase in very low birth weight. The investigators
estimated that if quarterly increases in male unemployment had been constrained
over the 23 years, 188 very low weight births could have been prevented in
Norway and approximately 329 in Sweden.
Other stressors, besides unemployment, may cause very low birth weight as
well, says Catalano. "It's not that the economic stress is any different
from any other stress," he says. "The reason that we use the economy as
the indicator is that that is one of these encompassing stressors that affects
many families and many individuals at the same point in time as opposed to the
more idiosyncratic and random individual events that we have
What is the biochemical connection between stressors and very low birth
weight? That is not entirely clear, according to Catalano, although it is known
that pre-term deliveries often result in babies of very low birth weight.
"It appears that the clock for birth is set relatively early in pregnancy
-- some people believe somewhere in the first trimester," he says. "If
the mechanism perceives a relatively high level of stress hormones in the
system, there is a perception that this female is stressed. The faster you get
this organism [baby] delivered, the less likely it is to be subjected to
whatever it is that is bothering the parent."
What can be done to prevent very low birth weight? "Certainly, how we
deal with unemployment and economic security is an issue that we have come to
grips with politically," says Catalano. "But probably we could do more
to reduce the incidence of physical adversity that follows from those events.
We have a lot of models to predict economic performance. Certainly, you can use
this information to, at least, predict the likelihood of these events occurring
and perhaps be ready for more of them." He suggests that social support for
women who are at risk for early delivery may result in the delivery of fewer