FAQ – Amniotest™  

Q: How does AmnioTest™ work?

A:  The pH of the vagina is normally acidic. Rupture of fetal membranes can result in small amounts of amniotic fluid leaking into the upper vagina. Amniotic fluid has a neutral pH.  Thus, the presence of amniotic fluid elevates the pH of the upper vagina.   AmnioTest™ is a sterile swab impregnated with nitrazine yellow dye that when brought in contact with the upper vagina will absorb fluid and develops a colour to correlate with the pH of the absorbed fluid ranging from pH 5.0 to pH 7.5.  A possible ruptured membrane is indicated if the swab has a pH of 6.5 to pH 7.5 turning the swab dark green to navy blue. A colour interpretation card is included with each box of AmnioTest™.


Q: What are the benefits of the AmnioTest™ Swab?

A: The benefits are as follows; AmnioTest™ comes in sterile, individually sealed, easy to open sleeves with identifiable expiry dates. AmnioTest™ conveniently combines nitrazine dye and the sampling swab together, thus eliminating the extra, cumbersome steps of traditional testing using pH paper. Using AmnioTest™ provides a standard method of practice for pH testing amongst staff.  AmnioTest™ meets all POC and laboratory accreditation requirements with the Colour Interpretation Card and the Q.C. buffers to match along with the training Education Power Points.

Q: I pressed the swab into the wet pad and it did not turn blue?

A: Initially, it is important to remember that the AmnioTest™ swab is not a protein-specific assay, but rather a pH indicator. Therefore, it does not identify amniotic fluid itself. Further, outside of the vagina, isolated amniotic fluid may not maintain its basic pH possibly due to its low buffering capacity.

PRO·Mcomplete  Pro-Lab’s protein specific test for detection of PROM  (Click here for more information)


Q: The patient seemed to have an obvious rupture yet the AmnioTest™ did not turn blue?

A: AmnioTest™ is designed to aid in detection of ruptured membranes not to confirm obvious ruptures.  If there has been an obvious rupture the pH of the vagina may no longer be elevated beyond a pH of 6.5.  Thus, the swab will not turn blue.

PRO·Mcomplete  Pro-Lab’s protein specific test for detection of PROM  (Click here for more information)


Q: What About False Positives?

A: False positives can be caused by a variety of factors. The most common cause of false positives are interfering substances that elevate the pH of the vagina. Such as the presence of blood, urine, semen, vaginal infections, some topical creams, and antibiotics.

PRO·Mcomplete  Pro-Lab’s protein specific test for detection of PROM  (Click here for more information)


Q: Can you get a false negative result?

A: Yes, for example if the patient’s clinical history indicates time from ROM greater than 12 hours the pH of the vagina may no longer be elevated.  Keep in mind, being a qualitative test, a negative result does not preclude the possibility of rupture of the fetal membranes.  Other clinical findings should be considered when interpreting a negative result.

Q: Does AmnioTest™ meet POC and Laboratory accreditation requirements?

A: Yes, AmnioTest™ swabs all have identifiable expiry dates on each sleeve.  There are six available AmnioTest™ Quality Control Buffers to match the colour interpretation card.  For new users, it is recommended that Quality Control be performed on a per box basis with six swabs and all six buffer solutions so that the user can become familiar with the product and interpreting the results. After which, the standard Q.C. regiment should be performed on a per LOT basis. (Q.C. record sheet can be found on the resource page). Extra colour interpretation cards can be ordered in packs of 50 cards for individual staff members. Further, training Education Power Points are available (Click here for documents).