Smaller babies from PCBs?

Sep 19, 2008

Halldorsson TI, I Thorsdottir, HM Meltzer, F Nielsen and SF Olsen. 2008.  With fatty fish consumption and reduced fetal growth among Danish pregnant women: a cause for concern? American Journal of Epidemiology online August 21, 2008.

Synopsis by Jennifer Adibi

Danish mothers who ate fish during pregnancy had higher PCB levels in their blood and smaller babies. This finding clouds advice to pregnant women about the benefits of eating fish.

Danish women who ate fish four or more times a month during their pregnancy had more polychlorinated biphenyls (PCBs) in their blood and their babies were born smaller and with smaller placentas. This finding adds to the controversy surrounding fish advisories directed at pregnant women that were designed to promote the healthy development of the fetus, but do not generally take into account the potential harm due to pollutants found in fish meat. PCBs are a highly toxic, highly persistent class of chemicals that are found in fatty fish despite the fact that they were banned from production and use in the 1970s. The women who had higher levels of PCBs had eaten salmon, herring, mackerel, trout and Greenland halibut. One hundred Danish women who were pregnant between 1998 and 2002 participated in the study. They filled out a questionnaire on food consumption midway through their pregnancy and gave 2 blood samples and a cord blood sample at delivery for PCB analysis. Approximately 33% of the women reported that they had eaten fish 4 or more times a month which is considered a moderate amount. The babies born to moms at a high range of exposure were smaller at birth by 155 grams and their placentas were smaller by 81 grams. These are small differences at an individual level but could be related to developmental and pregnancy disorders if amplified at the population level.