Using Canadian census data, a very large and therefore representative database, Canadian professor Douglas Allen of Simon Frazier University finds that children raised by intact, married biological parents do better than children raised by same-sex couples. From the abstract, yes, published in a peer-reviewed journal:
Here, a 20 % sample of the 2006 Canada census is used to identify self-reported children living with same-sex parents, and to examine the association of household type with children’s high school graduation rates. This large random sample allows for control of parental marital status, distinguishes between gay and lesbian families, and is large enough to evaluate differences in gender between parents and children. Children living with gay and lesbian families in 2006 were about 65 % as likely to graduate compared to children living in opposite sex marriage families. Daughters of same-sex parents do considerably worse than sons.