AmnioSense Clinical Studies

Clinical Studies

Using AmnioSense to Detect Amniotic Fluid Leakage.

Introduction: The AmnioSense panty liner is the only non-intrusive monitor for amniotic fluid leakage that can be used at home. It allows women to monitor for amniotic fluid leakage and differentiate this from urine leakage. The test has obvious benefits to both patient and healthcare professional. It also has possible cost benefits to the NHS because current guidelines require women be admitted if amniotic fluid leakage is suspected. Many such admissions are unnecessary and can create anxiety for patients and needless expense for the NHS.

Undetected leakage of amniotic fluid can also cause serious problems for both mother and baby. The risk of infection to both of them is is significantly increased if the amniotic fluid becomes contaminated.

Technology: The AmnioSense product conveniently monitors for amniotic fluid leakage whilst a woman goes about her normal daily routine. At the end of the day or as soon as any wetness is felt the woman simply removes an indicator strip from the panty liner and checks for a change in colour. If a blue-green colour is seen then amniotic fluid is present and the woman should immediately contact her midwife or doctor for further advice. The test is clearly of value to all women after 36 weeks of pregnancy but it is also of benefit after amniocentesis and any other high risk patient categories.

The AmnioSense test works by changing colour upon contact with amniotic fluid which normally has pH of 6.7 or more. The AmnioSense panty liner membrane is specific to amniotic fluid leakage and even if contaminated with relatively alkaline urine in the pH range 5.5-7.5 will not give a false positive results. The reason for this is that the technology gives a reversible colour reaction with urine after 10 minutes.

AmnioSense is also better than existing delivery room tests in the sense that it monitors continually whereas spot tests can give false negative results by missing intermittent leakage.

Clinical Study: In a clinical study involving 104 women, aged 20-40 years, entering hospital for a routine examination or for delivery. Each woman was given a single panty liner to use during the waiting period and the results obtained were compared to the Nitrazine pH test, visual check by a speculum examination and if negative by an additional ferning test. If subjects were suspected of having bacterial vaginosis or Trichomonas vaginalis infections a vaginal swab was obtained and sent for laboratory analysis. Of these 104 women studied 54 were shown to have amniotic fluid leakage (52 with identified wetness and 2 without any declared wetness) and 50 were shown to have no amniotic fluid leakage.

The overall results showed a sensitivity of 100% ie all 54 cases of confirmed amniotic fluid leakage were identified correctly, and a specificity of 84% ie 42/50 women had true negative results. However, the panty liner technology will also detect cases of vaginal infection, because of the presence of vaginal discharge with high pH, and it was noted that 4/8 women with false positive AmnioSense results were diagnosed as having bacterial vaginosis or Trichomonas vaginalis. The identification of vaginal infection is an important clinical observation and given that such cases require medical follow-up we conclude that the AmnioSense product yields an overall sensitivity of 100% and specificity of 92%.

Conclusions: This clinical study supports the use of AmnioSense as a monitor of amniotic fluid leakage which can bring support and comfort to all pregnant women and their healthcare providers by reliably identifying when amniotic fluid leakage occurs. The test is particularly beneficial to high risk groups because of its efficacy and the likelihood of reduced patient anxiety. The test has the additional advantage of detecting some cases of vaginal infection that will benefit from medical follow-up.

The test is a Class 1 Medical Device and is sold CE marked and compliant with the EU Medical Device Directive.