Prelabour Rupture of Membranes

Prelabour rupture of membranes (PROM) occurs when your “water breaks” before contractions start.

Preterm prelabour rupture of membranes (pPROM) occurs when your water breaks before contractions start and before you are 37 weeks pregnant.

PROM occurs in approximately 10% of pregnancies and 60-80% of those after 37 weeks.

The cause of PROM is poorly understood; however, a few factors have been associated with it, including a history of PROM in a previous pregnancy, infection, and cigarette smoking.

The majority of women go into labour on their own after rupture of membranes: 75% of women will be in labour within 24 hours, 90% within 48 hours, 95% of within 72 hours.

Signs of PROM

Trickling or gush of fluid that keeps coming (may be a lot or just a little).

Underwear or pad is wet.

May notice contractions after the initial rupture.

Other possibilities

Many women have an increase in vaginal discharge (leucorrhea), which is	typically thicker in consistency.

The “mucous plug” resembles a stringy discharge streaked with blood.

Some women have urinary incontinence, which has a stronger odour.

Risks of PROM

Endometritis (infection of the lining of the uterus) and chorioamnionitis (infection of the membranes) may cause PROM or result from prolonged PROM.

Neonatal infection (infection in the baby) can be increased with PROM because the membranes are no longer providing protection against bacteria.

The risk of infection has been shown to increase with a higher frequency of vaginal exams, as well as a longer period of rupture.

Cord prolapse, when the umbilical cord falls into the vagina in front of the baby’s head, is a rare emergency.

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Prelabour Rupture of Membranes

Management

If you think your water has broken:

Note the time, quantity, colour, and odour of the water.

Put a pad on to monitor the fluid.

Call your midwife immediately if:

You are less than 37 weeks pregnant.

The fluid is not clear (brown, green, or yellow) or smells bad.

You are GBS positive.

The baby is moving less than usual or not at all since rupture.

You feel the umbilical cord hanging in your vagina.

You are in active labour.

You are not planning a vaginal delivery.

Call your midwife within eight hours if there are no concerns (listed above). If it’s the middle of the night, you can wait to call your midwife in the morning to establish a plan going forward. The best thing to do is get more sleep before contractions start.

When you speak to your midwife, you will be offered two options:

Expectant management: continuing to wait for labour to start naturally.

Induction of labour: initiating labour artificially through the use of	medications. Your midwife will consult with the obstetrician on call at the hospital.

Things to consider for women who are GBS negative or did not do the GBS test:

Expectant management is as appropriate as induction of labour.

Obstetricians in this community recommend induction approximately 12 hours after PROM.

Midwives believe it is reasonable to wait up to 96 hours before induction.

The risk of infection increases from 10% to 40% after 24 hours after PROM.

Things to consider for women who are GBS positive:

The risk of infection is increased due to the presence of GBS.

The Society of Obstetricians and Gynaecologists of Canada recommends induction of labour immediately, typically within 6 hours of PROM.

The Association of Ontario Midwives supports offering either	expectant management or induction of labour with rupture less than	18 hours.

After 18 hours of rupture, induction of labour is recommended.