In a report filed on the U.S. National Laboratory of Medicine website, a case control study was performed using 292 women who had experienced unexplained spontaneous abortion at less than 14 weeks of gestation and 308 pregnant women who were at 14 weeks gestation.
For the consideration of cell phone effects, the study measured the average calling time per day, the location of the cell phones when not in use, the use of hands-free equipment, use of phones for other applications, the specific absorption rate reported by the manufacturer and the average of the effective specific absorption rate, which is the average duration of calling time per day × specific absorption rate.
The study demonstrated an increased risk of spontaneous abortions associated with EMF exposure and confirmed the results of other research. Despite the lack of a clear understanding of the underlying mechanisms, the result suggests that the use of cell phones may be related to early spontaneous abortions.
If you would like to examine the report for yourself, I have included a link to it below. Many more informative links are available in the report itself.