A woman's use of decongestant medications in the first
trimester of pregnancy may raise her child's risk of certain rare birth defects,
according to a small study.
Some types of over-the-counter decongestants, including the
popular phenylephrine and pseudoephedrine, were individually linked to rare,
specific birth defects of the digestive tract, ear and heart.
"Major birth defects of any kind affect about two to three percent
of live born infants, so they are rare," study author Dr Allen Mitchell
said. "The associations we identified involved defects that generally
affect less than 1 per 1 000 infants. Some of them may require surgery, but not
all are life-threatening."
Decongestants are some of the most commonly used drugs,
however, so fully understanding the consequences of taking them during
pregnancy is important, said Mitchell, director of the Slone Epidemiology
Center at Boston University. His team worked with a large collection of data on
babies born with birth defects between 1993 and 2010.
Nurses had interviewed the mothers of babies with birth
defects not caused by chromosome problems, and Mitchell's group analysed the
results for a total of 12 700 infants, comparing them to answers from the
mothers of 7 600 infants without deformities.
Mothers were asked about medications they took while
pregnant and in the two months before becoming pregnant. First-trimester use of
phenylephrine, which is found in Sudafed among other products, was tied to an
eight-fold higher risk of a heart defect called endocardial cushion defect.
phenylpropanolamine (Acutrim) was also linked to an eight-fold risk of defects
of the ear and stomach. All were associations that had been suggested by
earlier studies. But for the first time, the authors found links between
first-trimester use of pseudoephedrine (also in Sudafed) and a 3-fold higher
risk of so-called limb reduction defects.
Use of imidazolines (found in nasal decongestant sprays and
eye drops) was tied to an approximate doubling of risk for an abnormal
connection between the trachea and aesophagus. "The risks we identified
should be kept in perspective," Mitchell cautioned."The risk of an
endocardial cushion defect among babies whose mothers did not take decongestants
is about 3 per 10 000 live births.
"Even the eight-fold increase in risk indicated by the
study results, while it sounds large, would translate to a 2.7 in 1 000 chance
the baby would have the defect, he said. Assuming the findings are correct, he
added, the researchers could not speculate about why these drugs might be
linked to this handful of defects.
They found no link between the medications and several other
deformities that had been suggested by previous studies, such as clubfoot or
defects of the eye or face, according to the report published in the American
Journal of Epidemiology."This should offer some reassurance to women who
have taken these medications in pregnancy," Mitchell said.
Small absolute risks
"Since the absolute risks for these rare birth defects
are still very small, pregnant women should not be very worried after having
used these drugs," said Marleen van Gelder, an epidemiologist at Radboud
University Nijmegen Medical Center in the Netherlands who was not involved in
the study but has researched birth defects and decongestants
before."However, it should always be determined whether the beneficial
effects of treatment outweigh the possible risks for the developing
foetus," van Gelder told Reuters Health.
Mitchell believes there's enough evidence indicating a
possible connection to birth defects that doctors should not be recommending
that pregnant women take decongestants, but should evaluate each woman's need
for the drugs on a case-by-case basis.
"The fact that medications such as decongestants are
typically and widely available for use without a prescription and do not
require consultation with a healthcare provider should not be assumed to mean
they are safe with respect to the foetus, since there are still relatively few
studies that examine the risks and relative safety of these 'over-the-counter'
medications, which are more widely used in pregnancy than prescription
medications," Mitchell said.