Rh+ children of rh- mothers more likely to be disabled

Remember the previous studies indicating such?

Here is yet another study (from Dec. 2015) showing the same type of results:

There was a significant relationship between mother’s Rh blood and having disabled child (P=0.002). However no significant relationship between having disabled children and the following variables was found: the father’s Rh blood (p=0.2), father and mother’s Rh blood together (P=0.5), father blood type (P=0.56), mother blood type (P=0.42), and mother and father blood types together (P=0.7).

Coincidence?

Conclusion
Maternal and fetal blood incompatibility (mother with negative Rh blood and fetus with positive Rh blood) increased the likelihood of being born with disabilities.

See the study:

ABO and Rh Blood Type Relationship in Parents with more than One Disabled Child