Are amniotic fluid alpha-fetoprotein levels influenced by the gender in twin pairs?

Objectives: To examine the assumption that amniotic fluid alpha-fetoprotein (AFAFP) levels are different in female and male twin fetuses.

Design: Amniotic fluid levels of AFP in pregnancies with female and male fetuses in gender-concordant and gender-discordant twins were compared. A t test of p < 0.