Our results provide no support for the hypothesis of masculinization of female twins from opposite sex twin pairs. (insights.ovid.com)
Sharing of intrauterine environment in twins of opposite sex has been hypothesized to result in masculinization of the female twin. (insights.ovid.com)
According to The Philadelphia Center for Transgender Surgery, chest masculinization surgery includes removing female breasts to create a male chest, but doesn't remove all of the mammary tissue. (romper.com)