In a Kaiser Permanente cohort study published in 2017, 913 women were followed throughout their pregnancies. Researchers were examining the possible connection between high amounts of exposure to EMF radiation and the probability of miscarriage.

Study subjects were given special meters to track the amount of EMFs they encountered over a typical 24 hour period, and were asked to keep a log of the day’s activities along with where they took place. Additionally, the subjects were asked to note what parts of their day involved high EMF exposure. Researchers were careful to check for other risk factors of miscarriage among subjects in order to avoid false findings.

The results of the study were not comforting, yet weren’t entirely unexpected; expectant mothers who fell into the “high exposure” category (75% of the subjects) were nearly three times as likely to miscarry compared to the “low exposure” group.

This is consistent with the findings of multiple studies done on the subject over the last 15 years: This 2016 Chinese study exposed female mice to Extremely Low frequency, or ELF, magnetic fields throughout their pregnancy, with grim results. The exposed group produced 60 percent less offspring; spontaneous abortions and fetal deformities were prevalent in this group. Slowed development was also observed in the offspring that did survive.

Similarly, this 2013 study focused on the effects of Extremely Low frequency EMF radiation on humans. 116 women, half of whom had experienced miscarriage, filled out questionnaires (regarding socio-economic status, medical and reproductive histories), and had their homes tested for levels of EMF radiation. The group of women that lost their unborn children were found to have significantly higher levels of EMFs within their homes.

One thing worth noting about the Kaiser study findings is that within the high exposure group, which was further broken down into 3 subgroups based on exposure amount, there was no dose-response relationship between higher amounts of EMF radiation and miscarriage.

In other words, it seems that the risk posed by EMF radiation appears once a certain threshold is reached, but exposure amounts that go beyond this threshold do not continue increase risk in a linear sense.

Also, the specific sources of EMF radiation did not seem to be significant; rather, it was the consistency of exposure that made a difference in miscarriage outcomes. So, driving past a cell tower on your morning commute is likely less risky than using a laptop on your lap all day for work.