Response to Brody et al.

Dear Editor:

We appreciate the comments raised by Dr. Brody and colleagues. As they noted, our study characterizes mothers' breastfeeding behavior when they were informed of hypothetical, not actual, levels of phthalates in their breast milk. The purpose of our study was to determine if mothers wanted to know if chemicals are in their breastmilk and if knowing the results would potentially alter their breastfeeding practices. Our results showed that the majority of participants would discontinue breastfeeding if told that their milk contained environmental chemicals.

Dr. Brody and colleagues were concerned that our survey failed to provide a context or offer opportunities for further information. Indeed, we designed our survey to mimic how a typical study might report biomarkers of exposure and to discern potential problems of reporting individual test results. We also wanted to know whether and how participants want to receive test results.

The breastfeeding participants in our analysis are part of a longitudinal Cincinnati Children's Environmental Healthy Center project entitled the “Study of Prevalent Neurotoxicants in Children.” Within this larger study, multiple biomarkers are serially measured on each participant throughout pregnancy and early childhood. Since the early stages of this study we have been cognizant of how to appropriately and ethically inform participants of their results. Although our community advisory board recommended that we share all test results with participants, we wanted to know how they would want these results reported. Sixty-nine percent (238 of 343) said that they would prefer a mailed letter with a phone number to call if they had questions. Seventy percent (238 of 343) requested that each result be presented as an exact value within a range of other participants' results and a range of national data when available.

Our practice for reporting results are aligned with the National Academy of Sciences guidelines, ¹ mentioned by Dr. Brody and colleagues. We have developed a communication protocol for reporting on the effects of environmental chemicals. We also have made sure that there are knowledgeable personnel available to help participants and their families interpret their results. This process is very labor intensive and costly. Ideally, the investigators should request funding for this process at the outset, but historically there has not been sufficient funding for reporting biomarker results.

The results from our survey of breastfeeding mothers help us to understand the potential implications of reporting individual test results to research participants. Our aim was to determine how mothers might react to receipt of biomarker results in the absence of any context. We feel that it is beneficial to both research participants and scientists to examine the potential benefits and risks associated with various communication methods of study results.