In 2005, one study suggested that exposure to bisphenol A could be linked to recurrent miscarriages. The researchers found that high exposure to BPA was associated with recurrent miscarriages, particularly those that were associated with chromosomal abnormalities in the baby. But the study was small, as the researchers themselves admitted, with the experimental and control groups of too small size to draw sweeping conclusions -- and more research is needed to determine the effects of BPA on recurrent miscarriages.
Researchers in a 2003 study had found evidence that BPA exposure led to chromosomal problems in mice also -- specifically aneuploidy, a type of chromosomal abnormality frequently responsible for miscarriages in human beings. As opposed to other studies that have intentionally administered toxins to measure effects, the researchers uncovered the link between environmental conditions and aneuploidy after damage to the laboratory mouse cages led to a sudden increase in the rate of aneuploidy in the mice. They then followed up the hypothesis with other experiments that ended up supporting their hypothesis that, at least in mice, BPA could lead to chromosomal damage.
And in 2007, some of the researchers involved in the 2003 mouse study went on to find evidence that the effects of the BPA exposure could stretch for generations as well -- increasing the incidents of aneuploidy even in the eggs of female mouse fetuses that were exposed during the mother's pregnancy.
There isn't much other evidence on the relationship between miscarriage and bisphenol A, but many scientists feel that this isn't reason for reassurance and that the evidence of risk may yet be uncovered. The AAP has criticized claims that there is negligible concern for BPA having effects during pregnancy, stating that there is insufficient evidence to draw conclusions. Furthermore, in addition to pregnancy concerns, there is some evidence that early BPA exposure may affect children's neurological and behavioral development -- a matter that needs a lot more study before anyone should feel reassured that BPA is safe.
The above evidence has been disputed. Some researchers believe that the one study linking bisphenol A to recurrent miscarriages in humans used questionable methods and have analyzed the same data differently to find no link between recurrent miscarriages and exposure to BPA.
In addition, some research has questioned the finding that BPA increases the risk of aneuploidy in mice, suggesting that scientists do not currently understand whether BPA cases damage to chromosomes of developing cells and it may well be that it doesn't. (Note that most research does find that bisphenol A affects cell division -- researchers just don't agree on whether chromosomal abnormalities are the result.)
The National Toxicology Program (NTP), a government agency that evaluated the safety of bisphenol A and reviewed the available research, concluded that there was "negligible" reason to be concerned that normal levels of BPA exposure would lead to pregnancy complications, although it noted that a "minimal" risk could exist for women exposed occupationally -- and it did also state that there was "some" concern that normal levels of exposure to bisphenol A could affect a baby's neural development.
As far as BPA and miscarriage, it's too early to know the truth. Before you worry too much, note that nearly everyone is exposed to BPA and babies are still being born. There's no reason to believe that BPA exposure will prevent you from having a baby.
But looking at BPA overall, there's definite reason to be concerned about BPA -- especially with possible effects on neural development in young children. If you want to look into how to avoid BPA, that is a sensible choice. Alternatives exist in most cases that can reduce your BPA exposure. Yet it is true that there's no conclusive proof of risks at normal levels of BPA exposure, so it is also understandable to wait for firmer recommendations from governing bodies before making drastic changes to your routines.
Sources
Berkowitz, G., "Limitations of a case–control study on bisphenol A (BPA) serum levels and recurrent miscarriage." Human Reproduction 2006. Accessed 5 Sept 2008.
Eichenlaub-Ritter, U., E. Vogt, S. Cukurcam, F. Sun, F. Pacchierotti, and J. Parry, "Exposure of mouse oocytes to bisphenol A causes meiotic arrest but not aneuploidy." Mutat Res. Mar 2008. Accessed 5 Sept 2008.
Hunt, P., K. Koehler, M. Susiarjo, C. Hodges, A. Ilagan, R. Voigt, S. Thomas, B. Thomas, and T. Hassold, "Bisphenol A Exposure Causes Meiotic Aneuploidy in the Female Mouse ." Current Biology 2003. Accessed 5 Sept 2008.
Jenkins, Renee R., AAP President, Letter to Barbara Shane of
NTP Board of Scientific Counselors. 23 May 2008. Accessed 9 Sept 2008.
National Toxicology Program, "SInce You Asked - Bisphenol A." Accessed 5 Sept 2008.
Sugiura-Ogasawara, Mayumi, Yasuhiko Ozaki, Shin-ichi Sonta, Tsunehisa Makino, and Kaoru Suzumori, "Exposure to bisphenol A is associated with recurrent
miscarriage." Human Reproduction Jun 2005. Accessed 5 Sept 2005.
Susiarjo, M., T.j. Hassold, E. Freeman and P. Hunt, "Bisphenol A Exposure In Utero Disrupts Early Oogenesis in the Mouse." PLoS 2007. Accessed 5 Sept 2008.
US Food and Drug Administration, "Bisphenol A (BPA)." Apr 2008. Accessed 5 Sept 2008.
Vom Saul, Frederick S. and Claude Hughes, "An Extensive New Literature Concerning Low-Dose Effects of Bisphenol A Shows the Need for a New Risk Assessment." Environ. Health Perspect. Aug 2005. Accessed 5 Sept 2008.
Welshons, W.V. S.C. Nagel, F.S. vom Saal, "Large Effects from Small Exposures. III. Endocrine Mechanisms Mediating Effects of Bisphenol A at Levels of Human Exposure." Endocrinology 2005. Accessed 5 Sept 2008.
