There is a great deal of controversy about a recent study published by Prof. Mark Regnerus.
The study finds that in a narrowly defined family relationship of gay parents, that survey evidence does not support the widespread court testimony that gay families have the same or better child rearing outcomes than heterosexual families.
I am an expert on survey design. I looked carefully at the Regnerus study and find it is excellent. There are no comparable studies of this subject that are competent.
The Regnerus findings are based on reports from children who are now adults and whose own parents had 'some homosexual relationship' when they were growing up.
Since they were growing up in the 1980s, it was very rare for a stable gay couple to be raising children. Therefore the sample is much too small to be of any current relevance.
I don't expect to find a reliable study on this subject for another decade. Children whose parents were both openly gay and offering a stable relationship will not be in sufficient numbers until then.