Which test detects PROM by measuring the pH of amniotic fluid and is alkaline when PROM is present?

Which test detects PROM by measuring the pH of amniotic fluid and is alkaline when PROM is present?

• A. Fern test detects crystallization of salts in the amniotic fluid
• B. Nitrazine test detects pH of the fluid
• C. Ultrasound examination of the membranes
• D. Beta-hCG in vaginal fluid

Answer: (B)

When PROM is suspected, using a pH-based test works well because amniotic fluid is alkaline compared with vaginal secretions. The nitrazine test uses nitrazine paper that changes color to blue in alkaline conditions. If amniotic fluid leaks into the vagina, it raises the vaginal pH and the paper turns blue, signaling PROM. The fern test looks for the crystal pattern of dried amniotic fluid, which is not about pH. Ultrasound can evaluate membranes but doesn’t measure pH, and Beta-hCG in vaginal fluid isn’t used to diagnose PROM. Be aware that factors like semen, blood, or infection can alter vaginal pH and affect interpretation, but the pH-based change with nitrazine is the method that directly detects the alkaline amniotic fluid indicative of PROM.

When PROM is suspected, using a pH-based test works well because amniotic fluid is alkaline compared with vaginal secretions. The nitrazine test uses nitrazine paper that changes color to blue in alkaline conditions. If amniotic fluid leaks into the vagina, it raises the vaginal pH and the paper turns blue, signaling PROM. The fern test looks for the crystal pattern of dried amniotic fluid, which is not about pH. Ultrasound can evaluate membranes but doesn’t measure pH, and Beta-hCG in vaginal fluid isn’t used to diagnose PROM. Be aware that factors like semen, blood, or infection can alter vaginal pH and affect interpretation, but the pH-based change with nitrazine is the method that directly detects the alkaline amniotic fluid indicative of PROM.