I wish the proponents of the ABC link would STOP saying this. It is simply untrue. There are many many causes of miscarriage. One cause is insufficient progesterone but I have never read of insufficient estrogen being a cause, and I have read extensively although I am not a medical professional.
It is possible that some kinds of miscarriage are associated with lower estrogen levels. It is also possible that there is a more gradual decline of hormones in a miscarriage, rather than a sudden drop in an abortion.
Mrs VS
Good comment. We often test for and give progesterone if levels are low in women having troubles getting or staying pregnant.