Vaginal wetness is common during pregnancy. Around 20% of pregnant women report to hospital or birth units reporting wetness (Odunsi and Rinaudo, 2001). In most cases, it is harmless, resulting from urinary incontinence or changes to the vaginal secretions. However, dampness may indicate a rupture of the membranes.
Rupture
An amniotic sac can overstretch and cause an early rupture. Symptoms can easily be confused with urinary incontinence or increased vaginal discharge.
Premature rupture of membranes (PROM) occurs in around 10% of pregnancies. This is a rupture before 37 weeks, which is followed by spontaneous labour. These women need to be identified to ensure those who do not go into labour receive appropriate treatment. Women who have experienced PROM during a previous pregnancy are at increased risk of it happening again (O'Connor et al, 1999). Women who have undergone cervical surgery or those born with a shorter cervix are also at increased risk.
P-PROM is pre-term premature rupture of membranes and occurs in one in 50 pregnancies. In cases of P-PROM, the membranes rupture before 37 weeks but the mother does not go into labour within 18 to 24 hours. P-PROM is associated with 40% of pre-term deliveries and can lead to significant morbidity and mortality. The challenge for midwives is that often a diagnosis that can only be made retrospectively. It is crucial to identify women who have P-PROM but may not go into labour because a third of women (36%) who experience a confirmed P-PROM have an infection inside the womb. In some cases, there may be warning signs, such as raised temperature or an unpleasant vaginal discharge. In most cases the infection is subclinical, which means there are no obvious symptoms until amniotic fluid begins to leak out, or the waters break completely (Jolley and Wing, 2008).
Rupture after 37 weeks is described as spontaneous rupture of membranes (SROM) when the waters break naturally sometime after week 37 and the woman goes into labour.
Timing and treatment
Membranes can rupture at any stage of the pregnancy. The treatment options and outcomes depend on the baby's development, the extent and position of the tear and—most importantly—how quickly the mother receives medical care or goes into labour.
Many risk factors and variables will influence outcomes, but if a leak of amniotic fluid is suspected, it must be investigated at once because both the mother and child may need immediate attention.
Unless there is an obvious rupture, a speculum examination will be performed to determine if there is any pooling of amniotic fluid. It is not standard NHS practice to use acidity or Ferning tests for this purpose. However, current testing methods do not always detect non-continuous small ruptures and hind leaks, which is of concern for midwives as any leak of amniotic fluid increases the risk of a serious neonatal infection and early onset of labour (Santolaya-Forgas et al, 2007).
A new evidence-based test in the form of a two-staged diagnostic polymer strip located inside a panty liner has been proven to be as accurate as hospital-based examinations (Ferning test, sterile speculum examination and pH test). This test is approved by NICE and unlike a speculum examination, it allows for constant monitoring. Several studies have confirmed the accuracy, sensitivity and ease of use of this latest diagnostic tool (Bornstein et al, 2006; Mulhair et al, 2008; Odeh et al, 2011).
Conclusion
Timely adoption of simple, clinically proven diagnostics tests using the very latest technology helps provide reassurance and clear benefits for both maternity and midwifery healthcare professionals and women with suspected SROM, PROM and P-PROM.