It’s also possible that in this particular study done in Montreal on pregnant women that they eat a high percentage of organic fruits and vegetables, thus the detectable levels of Bt toxin. Are they able to distinguish the source of the Bt toxin detected?
Inquiring minds want to know.
Practically zero chance of that since organic foods are significantly more expensive and used by only a small percentage of any population. They'd have to seek out women who used organic produce to have such a study group. And Bt is probably not used on fruit and most vegetables other than the cabbage family. It's used mostly against leaf chewing insects that attack the cabbage family of vegetables.