From the Editor

How do you feel about expectantly managing a well-dated pregnancy past 41 weeks’ gestation?

OBG Manag. 2019 February;31(2):10, 12-13

References

Divon MY, Ferber A, Sanderson M, et al. A functional definition of prolonged pregnancy based on daily fetal and neonatal mortality rates. Ultrasound Obstet Gynecol. 2004;23:423-426.
Middleton P, Shepherd E, Crowther CA. Induction of labour for improving birth outcomes for women at or beyond term. Cochrane Database Syst Rev. 2018;5:CD004945.
Caughey AB, Sundaram V, Kaimal AJ, et al. Systematic review: elective induction of labor versus expectant management of pregnancy. Ann Intern Med. 2009;151:252-263.
Hannah ME, Hannah WJ, Hellmann J, et al; Canadian Multicenter Post-term Pregnancy Trial Group. Induction of labor as compared with serial antenatal monitoring in post-term pregnancy. N Engl J Med. 1992;326:1587-1592.
Delaney M, Roggensack A. No. 214-Guidelines for the management of pregnancy at 41+0 to 42+0 weeks. J Obstet Gynaecol Can. 2017;39:e164-e174.
Whitworth M, Bricker L, Mullan C. Ultrasound for fetal assessment in early pregnancy. Cochrane Database Syst Rev. 2015;7:CD007058.
Boulvain M, Stan C, Irion O. Membrane sweeping for induction of labour. Cochrane Database Syst Rev. 2005;1:CD000451.
Berghella V, Rogers RA, Lescale K. Stripping of membranes as a safe method to reduce prolonged pregnancies. Obstet Gynecol. 1996;87:927-931.
Avdiyovski H, Haith-Cooper M, Scally A. Membrane sweeping at term to promote spontaneous labour and reduce the likelihood of a formal induction of labour for postmaturity: a systematic review and meta-analysis. J Obstet Gynaecol. 2018:1-9.
de Miranda E, van der Bom JG, Bonsel G, et al. Membrane sweeping and prevention of post-term pregnancy in low-risk pregnancies: a randomised controlled trial. BJOG. 2006;113:402-408.
National Collaborating Centre for Women's and Children's Health. NICE Guideline 70. Induction of labour; July 2008. https://www.nice.org.uk/guidance/cg70/evidence/cg70-induction-of-labour-full-guideline2. Accessed January 23, 2019.
Hamdan M, Sidhu K, Sabir N, et al. Serial membrane sweeping at term in planned vaginal birth after cesarean: a randomized controlled trial. Obstet Gynecol. 2009;114:745-751.
Gibbon K. How to perform a stretch and sweep. Midwives Magazine. 2012. https://www.rcm.org.uk/news-views-and-analysis/analysis/how-to%E2%80%A6-perform-a-stretch-and-sweep. Accessed January 23, 2019.
Ryan KJ. Erosion of the rights of pregnant women: in the interest of fetal well-being. Womens Health Issues. 1990;1:21-24.

Routinely use ultrasound to accurately establish gestational age

First trimester ultrasound should be offered to all pregnant women because it is a more accurate assessment of gestational age and will result in fewer pregnancies that are thought to be at or beyond 41 weeks’ gestation.⁵ In a meta-analysis of 8 studies, including 25,516 women, early ultrasonography reduced the rate of intervention for postterm pregnancy by 42% (31/1,000 to 18/1,000 pregnant women).⁶

Membrane sweeping (or stripping)

Membrane sweeping, which causes the release of prostaglandins, has been reported to reduce the risk of late-term and postterm induction of labor.^7,8 In the most recent Cochrane review on the topic, sweeping membranes reduced the rate of induction of labor at 41 weeks by 41% and at 42 weeks by 72%.⁷ To avoid one induction of labor for late-term or postterm pregnancy, sweeping of membranes would need to be performed on 8 women. In a recent meta-analysis, membrane sweeping reduced the rate of induction of labor for postmaturity by 48%.⁹

Membrane sweeping is associated with pain and an increased rate of vaginal bleeding.¹⁰ It does not increase the rate of maternal or neonatal infection, however. It also does not reduce the CD rate. In the United Kingdom, the National Institute for Health and Clinical Excellence recommends that all clinicians have a discussion of membrane sweeping with their patients at 38 weeks’ gestation and offer membrane stripping at 40 weeks to increase the rate of timely spontaneous labor and to avoid the risks of prolonged pregnancy.¹¹ Of note, in one randomized study of women planning a trial of labor after CD, membrane sweeping did not impact the duration of pregnancy, onset of spontaneous labor, or the CD rate.¹²

Steps from an expert. A skillfull midwife practicing in the United Kingdom provides the following guidance on how to perform membrane sweeping.¹³

Prepare the patient. Explain the procedure, have the patient empty her bladder, and encourage relaxed breathing if the vaginal examination causes pain.
Abdominal exam. Assess uterine size, fetal lie and presentation, and fetal heart tones.
Vaginal exam. Ascertain cervical dilation, effacement, and position. If the cervix is closed a sweep may not be possible. In this case, massaging the vaginal fornices may help to release prostaglandins and stimulate uterine contractions. If the cervix is closed but soft, massage of the cervix may permit the insertion of a finger. If the cervix is favorable for sweeping, insert one finger in the cervix and rotate the finger in a circle to separate the amnion from the cervix.
After the procedure. Provide the woman with a sanitary pad and recommend acetaminophen and a warm bath if she has discomfort or painful contractions. Advise her to come to the maternity unit in the following situations: severe pain, significant bleeding, or spontaneous rupture of the membranes.

Membrane sweeping can be performed as frequently as every 3 days. Formal cervical ripening and induction of labor may need to be planned if membrane sweeping does not result in the initiation of regular contractions.

Continue to: Collaborative decision making

How do you feel about expectantly managing a well-dated pregnancy past 41 weeks’ gestation?

References

Routinely use ultrasound to accurately establish gestational age

Membrane sweeping (or stripping)

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