Everything you need to know about membrane sweeps

If you're approaching your due date or are already overdue, you'll likely be offered a 'membrane sweep'. At first, when you hear this, it might seem a bit terrifying, but it's actually a common way of inducing labour. The goal of a membrane sweep is to help start labour naturally and potentially avoid the need for more medical methods of induction. Read on to find out what this procedure is all about.

What is a membrane sweep?

A membrane sweep, also known as a cervical sweep or stretch and sweep, is a procedure sometimes performed to help induce labour in pregnant women who are near or past their due date. During the procedureOpens a new window, your doctor or midwife inserts a gloved finger into the cervix (the lower part of the uterus) and uses a sweeping motion to separate the membranes of the amniotic sac (which surrounds the baby) from the cervix. This action can release hormones called prostaglandinsOpens a new window, which may help to soften and dilate the cervix, potentially initiating labour.

Membrane sweeps are typically offered to women who are at least 38-40 weeks pregnantOpens a new window and may be considered if there are concerns about overdue pregnancy or if the mom-to-be is seeking to avoid a medical labour inductionOpens a new window. The procedure can be uncomfortable, and there's a risk of some side effects, including cramping, spotting, and, in rare cases, infection. However, many women find it a relatively low-intervention option compared to other methods of inducing labour.

How long after a membrane sweep will I go into labour?

After stripping the membranes, some pregnant women may go into labour within a few hours, while for others it may take a few days. Some may not go into labour at all.

Studies suggestOpens a new window that the chances of going into labour are increased during the 48 hours after a membrane sweep, with some research showing that about 50% of women experience the onset of labour within seven daysOpens a new window of a membrane sweep. However, effectiveness and timing can depend on factorsOpens a new window such as:

• Gestational age: How far along you are in your pregnancy can influence the effectiveness of a membrane sweep.
• Cervical readiness: If your cervix is already starting to dilate and efface, a sweep may be more effective.
• Individual differences: Each woman's body responds differently to induction techniques, including a membrane sweep.

If labour doesn't start after a membrane sweep, your doctor or midwife might discuss other induction techniques with you.

How painful is a membrane sweep?

The physical sensations experienced during a membrane sweep can vary. Some women describe it as uncomfortable rather than painful, while others may find it more painful. You may feelOpens a new window:

• Discomfort: Many women feel pressure and discomfort during the procedure. The sensation of a gloved finger inserted into the cervix can be uncomfortable.
• Cramping: It's common to experience cramping similar to menstrual cramps during and after the sweep.
• Pain: Some women report feeling pain, which can range from mild to more intense. The intensity depends on individual pain tolerance and the readiness of the cervix.
• Spotting or bleeding: Light spotting or bleeding after the procedure is normal and can add to the discomfort.

Breathing techniques, relaxation, and communicating with your healthcare provider about what you're feeling can help manage any discomfort. 

How likely is a membrane sweep to induce labour?

The likelihood of a membrane sweep inducing labourOpens a new window varies and depends on several factors. Studies and clinical experiences provide some insights into its effectiveness:

• General effectiveness: Most studies showOpens a new window that around 50% of people will go into labour within seven days of a membrane sweep.
• Gestational age: Membrane sweeps tend to be more effective when performed closer to or after your due date.
• Cervical readiness: If the cervix is already showing signs of readiness for labour, such as being dilated or effaced, the likelihood of labour starting after a sweep is higher.
• Individual differences: Each person's body responds differently to the procedure, so the success rate can vary.
• Number of sweeps: Sometimes, multiple sweeps are performed over a few days to increase the chances of inducing labour.

While a membrane sweep can increase the chances of labourOpens a new window starting naturally, it is not guaranteed to work for everyone. 

Are there risks that come with a membrane sweep?

Even though it is a natural labour induction method, there are some risks and potential side effects associated with a membrane sweep. Although it is generally considered a safe procedureOpens a new window, expectant parents should be aware of the following risks and potential side effects associated with a membrane sweep.

• Discomfort and pain: The procedure can cause discomfortOpens a new window or pain, as well as cramping similar to menstrual cramps.
• Spotting or bleeding: Light spotting or bleedingOpens a new window is common after a membrane sweep. Heavy bleeding should be reported to a healthcare provider.
• Infection: There's a slight risk of infection since the procedure involves inserting a finger into the cervix.
• Premature rupture of membranes: In rare cases, the procedure may cause the amniotic sac to rupture prematurelyOpens a new window, which can lead to other complications if labour doesn't start soon after.
• Irregular contractions: Some women may experience irregular contractions or cramping that doesn't lead to labour, which can be uncomfortable.
• Emotional impact: The procedure can cause anxiety or stress, especially if it turns out to be uncomfortable or if it doesn't result in labour starting.

It's important to talk about these potential risks with your midwife or OB so that you can make an informed decision. They can help you weigh the benefits and risks based on your individual situation and pregnancy.