Laura Vandenberg worries whenever she hears a pregnant friend talk about
painting a nursery. She gets even more concerned when she learns of a childbearing woman
spraying chemical pesticides on her lawn. "It sounds like a no-brainer, but you see it," said Vandenberg, a postdoctoral fellow in biology at Tufts University.
"If there is a group of people that could inform these women about
the dangers to an expected child," she added, "it is absolutely their
OB/GYNs."
Many reproductive health doctors remain largely unaware of both the
lengthening list of toxic chemicals their patients are exposed to every
day and the widening range of risks the chemicals might pose to a
vulnerable, developing baby -- from cancer to
obesity to lower IQ.
A pair of papers published this month highlight this dilemma, as well
as the public health benefits that could come with solving it. More
babies would grow up healthy, researchers say, if more obstetricians and
gynecologists use their unique positions to counsel women and inform
policies that eliminate toxic chemicals from a woman's environment in
the first place.
It took a patient asking if growing up in Love Canal, N.Y. -- home of
the infamous toxic waste site -- could have anything to do with her
recurrent miscarriages for Dr. Linda Giudice to connect environmental
exposures and human health.
"I didn't know what to say," recalled Giudice, chair of the
Department of Obstetrics, Gynecology and Reproductive Sciences at the
University of California, San Francisco, and a researcher on
one of the new papers.
Now, after educating themselves, Giudice and a growing number of
reproductive health physicians are cautioning patients to avoid things
like spraying pesticides while trying to get pregnant or during pregnancy.
"Every
mom wants to do the right thing for their baby," said Dr. Tanya Dailey,
an OB/GYN in Providence, R.I., and a researcher on the
other paper.
"We don't want to scare women, but we also want to limit exposures,"
added Dailey, who said she received little-to-no training on
environmental exposures during medical school, yet faces more and more
questions on the issue from patients. Now, Dailey might advise a
pregnant woman to eat only small fish, for example, explaining that
marine life lower on the food chain will accumulate less
mercury and other toxic chemicals.
Taking your shoes off before going inside the house is one of Dr.
Sheela Sathyanarayana's recommendations. That, and keeping carpets and
windowsills clean, can cut down on the array of toxic chemicals carried
by dust. Eating
fresh foods, she added, avoids
bisphenol A (BPA) and other chemicals commonly consumed via processed foods and leaching cans and plastic packaging.
"There are
simple things you can do
to reduce all of your exposures at once," said Sathyanarayana, a
pediatric environmental health expert at Seattle Children's Hospital and
lead researcher on the paper with Dailey. "But you can never get to
zero exposure -- that's just not realistic."
Dr. Tracey Woodruff has found that virtually all pregnant women in
the U.S. carry multiple chemicals in their body, including BPA,
dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls
(PCBs). Of the 163 chemicals analyzed in a study published last year,
43 were found in nearly all of the women tested.
"The burden is not just one or two chemicals -- it's actually many,"
said Woodruff, also a co-author on Giudice's paper. "And we know that
these chemicals can act together," with combined effects that may be
even greater than the sum of each acting alone.
A recent study led by Tuft's Vandenberg also shows that exposures to even
small doses of a toxic chemical can prove hazardouss -- in some cases, the smaller dose actually poses the higher risk.
What's more, scientists are learning that the consequences can last a
lifetime, even multiple generations. The groundbreaking evidence of
this latter phenomenon -- now an emerging science called epigenetics --
is based on the popular use of a hormone drug by pregnant women in the
1950s and 1960s. Touted at the time for preventing miscarriages,
diethylstillbestrol (DES) has now been associated with cancers and
reproductive defects in the exposed women's children, as well as their
children's children.
"Genetics alone can't explain all the things we observe in terms of familial disease patterns," said Woodruff.
Largely under Woodruff's lead, obstetrics and gynecologists in
California have weighed in on public policy matters including bans on
BPA in baby bottles and
flame retardants in furniture.
"As new legislation moves forward, we want the issue of pregnant
women to be adequately incorporated," said Woodruff, noting that laws
have not kept up with the deluge of chemicals in the marketplace or the
pace of science.
"While there are things they can do to minimize chemical exposures,
the burden should not all be on mothers," she added. "It should be on
industry and government agencies to make sure chemicals have been tested
and don't pose undue risks to children."