When Mom-to-Be’s Overweight and Smokes, Risk for Birth Defects Rises (HealthDay)

TUESDAY, Jan. 31 (HealthDay News) — Women who are both overweight and
smoke during pregnancy could damage their baby’s developing heart, a new
study warns.

Researchers in the Netherlands looked at nearly 800 fetuses and babies
with congenital heart defects, but no other birth defects, between 1997
and 2008. Congenital means present at birth. This group was compared with
more than 300 fetuses and babies born with chromosomal abnormalities, but
without any heart defects.

The results showed that women who were both overweight (body mass index
of 25 or more) and smoked during pregnancy were 2.5 times more likely to
have a baby with a congenital heart defect than women who either smoked or
were overweight during pregnancy.

The researchers also found that babies born to overweight mothers who
smoked during pregnancy had a threefold increased risk of outflow tract
abnormalities, in which blood flow from the ventricles of the heart to the
pulmonary artery or aorta is reduced or blocked.

The study was published online Jan. 31 in the journal Heart.

“These results indicate that maternal smoking and overweight may both
be involved in the same pathway that causes congenital heart defects,”
wrote Dr. Marian Bakker of the department of medical genetics at the
University Medical Centre, Groningen, and colleagues in a journal news
release.

The findings add to the growing body of evidence that smoking and being
overweight during pregnancy is associated with problems such as
miscarriage and stillbirth, stunted growth and premature birth, the
researchers said.

Heart abnormalities, one of the most common kinds of birth defects,
affect about 8 in every 1,000 babies. A likely cause is identified in only
15 percent of cases.

More information

The March of Dimes has more about heart defects.