Nope sorry never heard of it. The only connection between RH negativity and problems I have ever heard dealt with RH sensatitivity (which is why we get the rhogam shots).
I don't think the corrolation would be that strong. 15% of the population is RH - (but estimates of european descent individuals is 1 out of every 7 is RH- Eurpoeans are much higher because the mutation is thought to have occured in europe, about 7% of African-Americans are RH-), so you not only have to look at the woman being RH- but also the RH factor of the husband and the child (I have a RH + and a RH - child.. had PE/PIH with both).
One study I found between RH- and Hellp indicated that it was O- woman who had the increased risk