That could be, but my only point about the leafy greens is that most are not grown organically, and would not have been grown using Bt. So it's very unlikely more than a very few of the women in the test groups were eating organically grown greens. - They would not have ingested the Bt from the non-organic greens most would have eaten.
Unless Bt has replaced pesticides like Sevin for non-organic farming of greens, then the greens don't answer your question.
Except that the cohort MOST likely to consume more expensive organic greens is pregnant women, particularly in a liberal greeny enclave like Montreal for the previously stated reasons.