The Evidence Says: Stripping the membranes not consistently effective but consistently uncomfortable.

Frequently, I am asked to address traditional maternity care procedures and shine the light of evidence on these procedures.  Today, in response to a midwife's request,  The Evidence Says presents the most current findings regarding stripping membranes.

Do you have a topic that you would like addressed by Childbirth Today?  If so, email me at birthguru@birthsource.com!

Induction of labor is a highly controversial topic and one that requires careful consideration. 

Stripping or sweeping of membranes (the amniotic sac near the opening of the cervix) is one method care providers often use. 

How is it done ?

During a vaginal exam, the care provider places a gloved finger into the cervical os.  The closer edge of the membranes is detached from the lower uterine segment in a circular motion – not unlike peeling an orange.

Why is it done?

Stripping the membranes may begin labor by increasing local production of prostaglandins (hormone that will soften the cervix) by stretching of the cervix.  This intervention may shorten pregnancies of women who are at term (41-42 weeks) and may also reduce the need for induction.  However, some studies refute this finding³.

What the evidence indicates:

According to the most prestigious research database, the Cochrane database, stripping of membranes, while possibly shortening pregnancy by initiating cervical softening and irritating the uterine muscle, does not reduce cesarean rates in any population (nulliparous or multiparous women).  There was also no significant difference in maternal or neonatal infections.  It may not be the most effective means of inducing labor when there are medical indications.

Routine use of sweeping of membranes from 38 weeks of pregnancy onwards does not seem to produce clinically important benefits. When used as a means for induction of labor, the reduction in the use of more formal methods of induction needs to be balanced against women's discomfort and other adverse effects.

Discomfort associated with stripping membranes includes irregular contractions, spotting/bleeding, cramping and general discomfort – all of which may last for up to 24 hours.

Reasons You Would Not Want Your Membranes Stripped:

According to the American College of Nurse-Midwives (ACNM) Fact Sheet on Stripping Membranes¹, there are five reasons why an expectant mother may not want her membranes stripped.  They include:

• You have been told that it is not safe to have your infant vaginally.
• You have had unexplained vaginal bleeding during your pregnancy.
• You have been told that you need to have your infant urgently and it would be safest to have your labor induced by using medication.
• You want to let your pregnancy and labor unfold naturally and there is no medical reason to have your labor induced.
• If you have had a vaginal culture that says you have group B strep (GBS) in your vagina, you may not want to have your membranes stripped; there are no studies that have shown it is safe if you have GBS so this decision should be made with you and your care-provider making the decision together.

When might induction improve health outcomes of mothers and babies:

According to two studies^4,5, three situations showed small improvements in outcomes but left many unanswered questions.  These situations included:

• Pregnancy lasting beyond 41 weeks.
• Prelabor rupture of membranes at term.
• Increased blood pressure/preeclampsia at the end of pregnancy.

And a final word on reasons for induction that are not supported by research:

• Preterm prelabor rupture of membranes.
• Twin pregnancy.
• Gestational Diabetes requiring insulin.
• Intrauterine growth restriction (IUGR) before 37 weeks or at term.
• Oligohydramnios (too little amniotic fluid).
• Concern that the baby will get to big (suspected macrosomia).

Stripping of membranes and other mechanical methods of labor induction may begin labor but may also lead to additional interventions and methods of induction (such as Pitocin/ Syntocin) or even Cytotec.  It is important for careproviders to share all information with expectant mothers so that a well-thought out decision can be made.

References and Resources:

1. ACNM (2009) Fact Sheet: Stripping Membranes. Journal of Midwifery and Womens Health.
2. Boulvain, M. et al (2005) Cochrane Database: Membrane sweeping for induction. Last accessed 2/13/14 http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD000451.pub2/abstract;jsessionid=D4F9ECF1A89EEAB8143B5930D810A792.f03t02
3. Kashanian, M. et al. (2006) Effect of membrane sweeping at term pregnancy on duration of pregnancy and labor induction: a randomized trial. Gynecologic and Obstetric Investigation. 62(1): 41-4.
4. Koopmans CM, Bijlenga D, Groen H, et al. Induction of labour versus expectant monitoring for gestational hypertension or mild pre-eclampsia after 36 weeks' gestation (HYPITAT): A multicentre, open-label randomised controlled trial. Lancet. 2009;374(9694):979-988. 
5. Mozurkewich E, Chilimigras J, Koepke E, Keeton K, King VJ. Indications for induction of labour: A best-evidence review. British Journal of Obstetrics & Gynecology. 2009;116(5):626-636.

The Perfect Response by Barbara Harper

My long-time friend, Barbara Harper (founder of Waterbirth International), posted this on her Facebook page. I found her dialogue so phenomenal, I asked her permission to reprint.  So here it is..in Barbara’s words….

There was a commentator on the radio in Miami this morning (10/18/12) extolling the virtues of planned cesarean surgery and induction because you can guarantee that your doctor will be there as one reason to "control" the birth of your baby. This was my response:

To the uninformed person who commented on the convenience and safety of inductions and scheduled cesarean surgery instead of waiting for the perfectly timed dance of undisturbed childbirth: 

Barbara Harper

All human beings are programmed by brain wiring and influenced by the environmental signals to initiate the birth process through a complex set of chemical, hormonal and neurological transmitters. The new human needs that process to fully engage and activate parts of the brain that contribute to health, well-being, cardiovascular stability, respiratory function, neurological development and even feelings of love and attachment. 

When we arbitrarily assign a date to chemically initiate the process, the innate programming gets shut down, cannot function in the same way as the biological imperative would have, had things been left alone. The human being perceives this "jump start" as a threat and begins to prepare its body and brain to survive in an environment that is stress filled and possibly life threatening. All of the bodily functions that control the neurological, cardiovascular, respiratory, metabolic adaptive mechanisms are put on high alert and remain there. This over stimulation of the psychoneuroimmunological system creates and lays down the patterns for future problems such as heart disease, high blood pressure, diabetes, chronic obstructive pulmonary disease and even some psychiatric disorders. 

This may be difficult for the uninformed consumer to begin to see the connections between the use of a simple drug to stimulate the uterine contractions or a surgical procedure to remove a human being from the habitat in which brain development is meant to take place, but the growing field of epigenetics and pre and perinatal psychology are rapidly filling in the gaps in our understanding that what we do in the birth process has life-long consequences on human health, the development of character, mental stability and perhaps even drug addiction. Tall order? Perhaps we are only beginning to realize the long term effects of this violation of an innate biological agenda - because that is what early chemical induction is!

As they say, "don't mess with Mother Nature!"

These scientific principals and the evidence to support this thesis are contained in my forth coming book, "Embracing The Miracle: How Pregnancy, Birth and the First Hour Influence Human Potential."  There are already many books and hundreds of research studies from which to broaden your understanding of allowing nature to fulfill its destiny in the creation of new human beings. Parenting For Peace by Marcy Axeness is a great book for any potential parent or grandparent along with my other book, Gentle Birth Choices .