Assessing Second-Trimester Ferning in Diagnosing Preterm Prelabor Rupture of Membranes.

Objective:  Preterm prelabor rupture of membranes (PPROM) diagnosis is made through visualization of amniotic fluid (pooling), nitrizine testing, sonographic low amniotic fluid, and microscopic detection of amniotic fluid arborization (ferning). Data exist on the specificity and sensitivity of ferning detection but have not focused on the second trimester. Our objective is to evaluate the presence of ferning in transvaginally collected amniotic fluid in pregnancies with known second-trimester PPROM to determine if there is a difference in ferning based on gestational age and sample drying time.