What is ferning of amniotic fluid?

Ferning of amniotic fluid is a microscopic appearance of the fluid that surrounds the fetus during pregnancy. This test is conducted to check the rupture of membranes, which is often an indication of preterm labor. Amniotic fluid has high levels of estrogen and salts that help in the formation of a fern-like pattern when viewed under a microscope. This pattern can be observed when a small amount of amniotic fluid is placed on a glass slide and allowed to dry.

The ferning test is a simple and non-invasive procedure, and it can provide critical information regarding the health of the baby. Doctors usually conduct this test if there is a suspicion of premature rupture of membranes, which can lead to complications like low birth weight and preterm labor. A negative fern test suggests that the membranes are intact, while a positive ferning test indicates a rupture.

It is important to note that the ferning test has limitations, and further testing may be needed to confirm the presence of amniotic fluid. False positives may occur if there is cervical mucus or bacterial vaginosis present. Therefore, it is essential that medical professionals perform other tests, like vaginal pH and nitrazine tests, before proceeding with intervention.