Membrane Sweep: is it Safe?

Hey expecting mama, you may be wondering what a membrane sweep is! It has nothing to do with a broom! I’m here to give you the education you need to make an informed decision.

Membrane sweeping or membrane stripping is a procedure that has been reported since the 19th century as a way to stimulate labour. The procedure is done with a vaginal exam by your healthcare provider at a routine prenatal appointment. Your healthcare provider will gently separate the membranes (the sac around your baby) from your cervix with their finger if your cervix is open. This procedure encourages the release of endogenous prostaglandins that soften the cervix and may encourage contractions.

When can this procedure be offered?
Anytime after 38 weeks gestation

Do I have to have a membrane sweep?
No! It is your decision whether you would like to have a membrane sweep after a
discussion of the benefits and risks with your healthcare provider.

What are the benefits?

Plasma prostaglandins levels after a membrane sweep are 10% of those achieved with labour therefore possibly improving labour outcomes
Can be beneficial for first time mamas with an unfavourable Bishop score (Tool used by clinicians to determine cervical status)
In some trials, membrane sweeping has been an effective outpatient method for reducing pregnancies that go beyond 41
May decrease the need for formal induction at 41 weeks gestation
May promote spontaneous labour

What are the risks?

  • Unintentional rupture of membranes (water breaking), rare
  • Chorioamnionitis, rare
  • Bleeding from an undiagnosed previa, rare as it is usually diagnosed by ultrasound
  • Potential increased incidence of prelabour rupture of membranes (mixed studies)

What are the side effects?

  • Cramping
  • Spotting
  • General discomfort

Is it safe?
Multiple studies have established membrane sweeping as a safe practice that does not increase maternal or fetal morbidity or mortality.

What does the research say?

  • Studies on membrane sweeping are mixed
  • A recent Cochrane review assessed 22 trials involving sweeping membranes. Sweeping of the membranes at term (38–41 weeks) reduced the frequency of pregnancies continuing after 41+0 weeks. Eight women would need to undergo sweeping of membranes to prevent one induction of labour.
  • In a study by Berghella et al.,45 patients were randomized to weekly sweeping of membranes or gentle exams starting at 38 weeks. Time to delivery was significantly decreased with membrane stripping, and there were fewer pregnancies reaching past 41+0 weeks.
  • A well-designed Canadian study enrolled patients at 38 to 40 weeks, and did not find any differences between a single membrane sweeping and routine examination with respect to onset of after 41 weeks or need for induction of labour.
  • In another study, both the induction-to-labour interval and oxytocin use were decreased, and there was an increased rate of normal vaginal delivery.
  • Research suggests that pregnancy exceeding 42 weeks gestation is associated with an increased risk of perinatal morbidity and mortality.
  • A study by Avdiyovski, Haith-cooper & Scally demonstrated membrane sweeping is effective in promoting a spontaneous labour and thereby reducing the need for formal induction.

What does SOGC (Society of Obstetricians and Gynaecologists of Canada) recommend? The SOGC recommends that women should be offered the option of membrane sweeping commencing at 38 to 41 weeks, following a discussion of risks and benefits.

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