Do single mother homes statistically produce more children?

This is not a morality question or a religious based question. All answers must provide actual sources that back them. I am not anti gay nor pro gay. I want to know if there has ever been a study to see if single parent homes produce a higher percentage of ual children or less than average percentage. I am not asking for people to tell me ity is something people are born with or not born with. I am looking to see if a study has been done to see if there are differences.