Women who get allergy shots
before or during pregnancy may lower the odds that their offspring will suffer
from asthma, food allergies or eczema, a preliminary new study suggests.
Reviewing anonymous surveys
from 143 mothers who had received allergy shots also known as immunotherapy,
researchers from the University of Tennessee Health Science Centre in Memphis
found a 10% to 12% reduced rate of allergies among the women's children.
"It was our hope that
allergy shots would help, and I wasn't surprised," said study author Dr
Jay Lieberman, an assistant professor of paediatrics at the centre. But, he
added, "I wouldn't say this [research] is the end-all and be-all. We would
love better data. This provides some background data to say this should be
looked into further."
Controlling the symptoms
Lieberman said the small
number of participants lowered the impact of the results. "A drop of 10%
to 12% [in children's allergy rates] is meaningful, but is not statistically
significant," he said. "But I would call that clinically
The study is scheduled to
be presented at the annual meeting of the American College of Allergy,
Asthma and Immunology (ACAAI) in Baltimore. Research presented at scientific
meetings typically has not been peer reviewed or published, and results are
More than 50 million
Americans suffer from allergies of all types, including seasonal and food
allergies, as well as asthma and the skin condition eczema. If both parents in
a family suffer from allergies, their offspring have a 75% chance of following
suit, according to the ACAAI.
Those odds drop to 30% to
40% for children with only one allergic parent, and up to 15% for children with
no parental allergies.
Although allergies have no
cure, allergy shots monthly injections for three to five years once a maintenance
dose is achieved have been shown to control and sometimes eliminate symptoms.
Taking into account the
children's breastfeeding status, gender and other factors that affect allergy
risk, Lieberman and his team found that kids whose mothers received allergy
shots during pregnancy were 12% less likely to also develop allergies.
Those odds changed to 10%
less likely for those whose mothers received allergy shots before pregnancy.
Of children whose mothers
did not receive allergy shots, 62% were diagnosed with allergies compared with
52% of those whose mothers had the shots.
Dr David Bernstein, a
professor of medicine and environmental health at the University of Cincinnati,
said it makes sense that the offspring of pregnant mothers receiving allergy
shots might later gain some immunity from allergies.
"I think this research
raises interesting possibilities," said Bernstein. "We're trying to figure out why the instances of allergies have
increased so dramatically and what to do about it. So it's interesting to
speculate what can happen in utero when pregnant women are already receiving
There appears to be no
drawbacks for foetuses exposed to allergy shots during their mothers'
pregnancy, study author Lieberman said. Current clinical recommendations
suggest pregnant women continue receiving the same injection dose as before
pregnancy but not increase it, he said.
Lieberman has not planned a
larger study to confirm the findings, but hopes other researchers will follow
up on the data.
"I think a real-world
trial that follows women... for 10 or 20 years would be feasible and
ideal," he said.
Learn more about allergies
from the US National Library of Medicine.