A monoclonal antibody test for the presence of alpha-fetoprotein (AFP) in vaginal secretions, used in cases of suspected premature rupture of membranes. In healthy pregnancies AFP is detectable in the amniotic fluid but is present only in very low concentrations in vaginal secretions. If there is leakage of amniotic fluid into the vagina as a result of premature rupture of membranes, AFP levels in the vagina rise significantly.