A preterm mother comes into the hospital with concern of premature rupture of fetal membrane. Essentially, this means her water broke before 37 weeks. An AmniSure test is performed on the vaginal secretion to detect the presence of amniotic fluid in the secretion. The test comes out positive, indicating the amniotic sac has ruptured. The fern test is another method to detect amniotic fluid in vaginal secretions, though less specific and less sensitive than more modern methods. This means it is prone to false positives and false negatives. A drop of the vaginal secretion is placed on a glass slide and allowed to dry. The amniotic fluid present in the secretion dries in the following fern pattern as expected.