A blue strip means it's more likely the membranes have ruptured. The strips will turn blue if the pH is greater than 6.0.

The strips change color depending on the pH of the fluid. This test involves putting a drop of fluid obtained from the vagina onto paper strips containing nitrazine dye. This test is done to ascertain the nature of fluid in the vagina during pregnancy especially when premature rupture of membranes (PROM) is suspect.Nitrazine is usually used as the disodium salt. More sensitive than litmus, nitrazine indicates pH in the range of 4.5 to 7.5. A 26 y/o G1 weeks gestation presented to the hospital exam room after noticing her “underwear was wet.Nitrazine or phenaphthazine is a pH indicator dye often used in medicine. A 26 y/o G1 weeks gestation presented to the hospital exam room after noticing her “underwear was wet.” What causes false positive nitrazine test?Ĭlinical Scenario A. If blood gets in the sample or if there is an infection present, the pH of the vaginal fluid may be higher than normal. This test, however, can produce false positives. A blue strip means it’s more likely the membranes have ruptured.

What does Nitrazine positive mean? Nitrazine Test The strips will turn blue if the pH is greater than 6.0. What does a positive nitrazine test signify? What causes positive Nitrazine test? Nitrazine test may also lead to false positive or negative results due to probable contamination by alkaline urine, semen, blood, meconium, vaginitis, cervicitis and using antibiotics.

What is the Nitrazine test in pregnancy? What causes positive nitrazine test? Because pH in the upper vagina is normally acidic (pH 3.8-4.5), a vaginal pH test showing a pH of more than 4.5 strengthens a suspicion of rupture of membranes in case of clear vaginal discharge in pregnancy. The test was interpreted as positive if the test paper turned blue.Īmniotic fluid normally has a pH of 7.0 to 7.5. Vaginal pH is normally between 4.5 and 5.5 but the presence of amniotic fluid in the vagina increases the pH value. What is Nitrazine paper used for? What is a Nitrazine test? Assessment of membrane rupture in pregnant women as described in the Procedure for Premature Rupture of membranes (PROM) as found in the OB GYN Policy and Procedure Manual. Nitrazine (phenapthazine) paper is used to measure vaginal pH in two settings. On the other hand, false negative results can be obtained when the amount of fluid available for analysis is scant. However, a nitrazine test can give a false positive result if the sample is contaminated with blood, semen or antiseptics, or if the patient has vaginitis or cervicitis. Nitrazine Test This test involves putting a drop of fluid obtained from the vagina onto paper strips containing Nitrazine dye. Dried normal vaginal fluid does not produce a “fern” pattern. Dried amniotic fluid produces a microscopically visible crystallization in a “fern” pattern. How do you test for amniotic fluid Ferning?Įxamine the air-dried smear under the microscope without a coverslip and using low power magnification (10x magnification). Though the pH of urine ranges from 4.0 to 8 3, it also contains ammonia. The strip is also able to eliminate any false readings caused by incontinence. What is the pH of amniotic fluid and urine?Īmniotic fluid has a pH of 6.7 or more, while normal vaginal secretions are 3.5 to 4.5. Amniotic fluid normally has a pH of 6.5 or above whereas vaginal pH is 3.5–4.5.

Nitrazine ph test strip amniotic fluid