Source: ACOG Today, February 2013
Published by the The American Congress of Obstetricians and Gynecologists
Around 1986, Linda C. Giudice, MD, Phd,MSc, (right) had a conversation that changed the course of her career. "It was when I was at Stanford, and a patient in my practice called," said Dr. Giudice, now an endowed professor and chair of the department of Obstetrics, Gynecology & Reproductive Sciences at University of California, San Francisco. "She asked me whether I thought her recurrent miscarriages had anything to do with growing up near a Superfund site."
Nearly 30 years after that conversation, Dr. Giudice wouldn't say she's resolved whether miscarriages are related to living near pollution, but she has been a pioneer in an emerging field: reproductive and environmental health. In recent years, the field—which posits that environmental hazards such as pesticides can affect health— has transitioned from a theory of the fringe left to a topic of serious scientific inquiry. In 2011, a presidential panel reported that 80% of cancers are caused by the environment.
In Dr. Giudice's Donald F. Richardson Memorial Lecture at the Annual Clinical Meeting, she'll explore the state of the science and show clinicians how to be an advocate for their patients. The symposium session will be held on Monday, May 6, from 2:50 to 3:50 pm. "It is definitely an emerging area," said Dr. Giudice, who co-authored a paper in the September 2012 issue of the American Journal of Obstetrics and Gynecology with ACOG President Elect Jeanne A. Conry, MD, PhD, that calls on ob-gyns to help patients avoid chemical exposure.
Effects across the lifespan
Nowhere has the issue of environmental toxins been as publically discussed as in the debate over bisphenol A, or BPA, a chemical used in plastics since the 1960s. In 2006, The New York Times reported that parents were avoiding products containing BPA. Soon, research showed that BPA appeared in women's breast milk and umbilical cord blood and that BPA might accelerate puberty and increase cancer risk. By 2012, the US Food and Drug Administration had banned it for use in baby bottles and sippy cups.
BPA, like many chemicals, is estrogenic in nature—that is, it mimics estrogen, which can trigger growth in estrogen-receptive cancers. Many environmental toxins are either estrogenic or anti-androgenic, blocking androgen. Both of these, emerging evidence seems to suggest, can not only increase a mother's risk for cancers, but can also alter the expression of a fetus's genes.
"All the emerging evidence suggests that fetal exposure to a variety of things in pregnancy can alter not only anatomic development but also alter the susceptibility to disease later in life," Dr. Giudice said. "It doesn't change the genes, but nutrition and environmental changes can change the pattern of the DNA and its expression."
Call to action
Given the evidence, Dr. Giudice is hopeful that ob-gyns will start to address environmental toxicity with their patients. Some already have. She was part a team that surveyed 20,000 ob-gyns to ask if they talk to their patients about chemical exposure. The results are still being studied, but preliminary results found that a fraction do. She also hopes for a new subspeciality in reproductive environmental health. Dr. Giudice hopes all of this work will help raise awareness without creating undo alarm. "We don't want people to go crazy and be afraid of living in the world," she said. "But we do want to give them the opportunity to minimize risk."