Blood type and speed of birth

[AndiE]

I'm B-
DS1 total labour approx 8 hours, mild/easy contractions with only last 2-3 hours active labour.
DS2 total labour approx 7 hours, as with DS1 it was mild with only last 2 hours active labour.

For the purpose of LM's theory - DS1 is B+ and DS2 is B-