A membrane sweep, also known as a stretch and sweep, is a procedure done late in pregnancy to try to induce labor naturally. It involves a doctor or midwife sweeping their finger around the cervix to separate the membranes of the amniotic sac from the cervix. This releases hormones called prostaglandins that can help soften and dilate the cervix, which could kickstart labor. However, a sweep does not always lead to labor starting on its own. Here is some more information on whether induction is required after a sweep.
What percentage of women go into labor after a sweep?
Studies show that sweeping the membranes results in increased rates of spontaneous labor and birth. However, there is a wide range of estimates on exactly how effective membrane sweeping is at bringing on labor:
- Some studies have found between 10-25% of women will go into labor within 48 hours of a sweep.
- Other studies estimate between 20-50% of women will go into spontaneous labor after a sweep.
- One analysis found that around 27% of women who had a membrane sweep delivered within 48 hours, compared to around 6% of women who did not have a sweep.
So while membrane sweeping seems to make labor more likely, there is no guarantee it will induce labor. At least half of women will not go into labor within 48 hours after a sweep. The success rates seem to depend on a few factors:
Factors that affect success of sweep
- Cervical ripeness – Sweeps are more successful when the cervix is already thin, soft and partly dilated. If the cervix is still firm and closed, a sweep may not be very effective.
- Bishop score – This is a rating system from 0-13 that assesses cervical ripeness based on dilation, effacement, position, consistency and station. Higher scores indicate increased likelihood a sweep will initiate labor.
- Gestational age – Sweeps done at term, from 37-40 weeks, tend to be more successful than earlier sweeps.
- Parity – Primiparous women (first time mothers) have lower rates of labor after a sweep than multiparous women.
- Amount of separation of membranes – More separation and release of prostaglandins during the sweep increases chances of labor.
Overall, the ripeness of the cervix seems to be the biggest factor in whether a sweep will successfully initiate labor. Women who are already partially effaced and dilated have the highest success rates.
When would induction be recommended after a sweep?
If labor does not start within 24-48 hours after a membrane sweep, your doctor or midwife will likely recommend induction. However, there are some situations where induction may be suggested sooner:
- You are past your due date – Induction is often offered between 41-42 weeks to avoid risks of going post-term.
- You have medical issues like diabetes, high blood pressure, etc.
- There are concerns with the baby’s growth or well-being.
- Your water breaks but labor does not start.
- You have a history of fast labors.
- You live far away from the hospital.
During induction, medications or other methods will be used to stimulate uterine contractions and cervix changes to start labor artificially. Common induction techniques include:
Methods of induction
- Oxytocin (Pitocin) – Synthetic form of the hormone oxytocin given through an IV to cause contractions.
- Foley balloon catheter – A catheter placed in the cervix and inflated to put pressure on the cervix.
- Artificial rupture of membranes (AROM) – Breaking the amniotic sac to release prostaglandins.
- Prostaglandin medications – Given as a vaginal insert, pill or gel to soften the cervix.
- Membrane stripping – Repeated sweeping of the finger around the cervix.
During the induction process, your labor will be closely monitored by your doctor or midwife. How long induction takes varies between women – it could be as short as a few hours or upwards of a day or longer. Some women may fail to respond to induction medications and need a c-section if labor does not progress.
What are the pros and cons of induction after a sweep?
Here are some of the key pros and cons of proceeding with induction after membrane sweeping has failed to kickstart labor:
Pros of induction after sweep
- Avoids risks of going past your due date like the baby getting too big.
- Delivers the baby in a controlled setting with close monitoring.
- Having an endpoint gives you a timeline versus continued waiting.
- Prevents potential complications like cord prolapse if water breaks at home.
Cons of induction after sweep
- Increases chances of needing interventions like vacuum, forceps or c-section.
- Can be more intense and painful than natural labor.
- Risks like infection, excessive bleeding, fetal distress are higher.
- Newborns are more likely to have issues like low APGAR scores.
The risks of induction are relatively low in most cases. However, choosing induction electively versus for medical necessity does increase the chances of needing a surgical delivery. Some women wish to wait longer for natural labor to start versus rushing into an induction after a failed sweep.
What percentage of women are induced after a sweep?
There are not comprehensive statistics on the rate of induction after membrane sweeping. However, we do know:
- Around 10% of women have a membrane sweep done before labor.
- Up to 50% of women may not go into labor within 48 hours after a sweep.
- The rate of labor induction in the US is around 23%.
Based on these numbers, a reasonable estimate would be that around 5-10% of women end up getting induced after having an unsuccessful membrane sweep sometime during the last weeks of pregnancy. However, more statistics are needed on rates of induction specifically after sweeping.
Here is a table summarizing the key statistics on membrane sweeping and labor induction:
| Statistics on Sweeps and Induction | Percentages |
|---|---|
| Women who get a membrane sweep | 10% |
| Women who do not go into spontaneous labor within 48 hours after sweep | Up to 50% |
| Rate of induction of labor in the US | 23% |
| Estimated rate of induction after unsuccessful sweep | 5-10% |
What can you do to encourage labor after a sweep?
If your doctor or midwife performs a membrane sweep but labor does not start on its own, here are some tips that may help encourage the onset of labor naturally before resorting to induction:
Tips to encourage labor after a sweep
- Have sex – semen contains prostaglandins that can help ripen the cervix
- Take evening primrose oil capsules – helps soften the cervix
- Do nipple stimulation – releases oxytocin to promote contractions
- Walk and stay active – movement may help labor progress
- Eat dates – contains compounds that stimulate contractions
- Drink red raspberry leaf tea – tones the uterus
- Get acupuncture – shown to promote cervical ripening
- Use a breast pump – sucking action releases oxytocin
- Take a warm bath – can relax pelvic muscles
- Bounce on a birth ball – may help baby descend into pelvis
However, there is no foolproof way to guarantee labor will start naturally after a sweep. Speak to your healthcare provider about how long to wait before considering induction if your sweep does not kickstart labor within 24-48 hours.
Conclusion
Membrane sweeping helps induce labor in around 20-50% of women within 48 hours. However, many women will not go into labor after a sweep and will need to discuss options like induction with their healthcare provider, especially if they are past their due date. While some women wish to wait longer for natural labor, induction is often recommended after 24-48 hours from a failed sweep, particularly if there are medical concerns. An estimated 5-10% of women end up getting induced after unsuccessful membrane sweeping sometime in late pregnancy. If labor does not start after a sweep, techniques like sex, nipple stimulation and acupuncture may encourage the onset of natural contractions before resorting to medical induction methods.
