By PT Staff, published on July 1, 1994 - last reviewed on January 23, 2015
Mothers who smoke while pregnant may be knocking as many as four
points off their baby's IQ. But intensive prenatal care may offset the
The deficits turned up in a Cornell University study of three-and
four-year-old children of 400 mothers who smoked at least 10 cigarettes a
day when pregnant. Tots whose mothers received routine home visits from
nurses during pregnancy had IQs five points higher than smokers who were
What accounts for the rebound? "The nurses were able to curb the
mothers' smoking. But that's not all of it, contends Charles Henderson,
research associate and coauthor of the study, reported in Pediatrics
(Vol. 93, No. 2). They also improved the eating habits of the moms, 85
percent of whom were either teenagers, unmarried, or poor.
The nurses gave them all kinds of health guidelines, covering
everything from nutrition, infection prevention, the appropriate use of
medical care, and what to expect when the child arrives. They made
hour-and-a-quarter visits about every two weeks, averaging nine visits
throughout the pregnancy. They followed some of the families for two
years, visiting about 23 times.
The researchers are convinced that prenatal care compensated for IQ
deficits that would have shown up otherwise. They are also adamant that
the two years of follow-up, which involved advice on infant care giving,
support systems, and the healthcare system, made a big difference in the
Not to mention the mothers' lives. The nurses also helped the women
complete their education, find jobs, and plan future pregnancies.