Cervical Ripening

Aka: Cervical Ripening, Membrane Stripping, Cervical Membrane Sweeping

1. Medications: Standard
   1. Dinoprostone (PGE2 Gel, Cervidil, Prepidil)
   2. Misoprostol (PGE1, Cytotec)
2. Procedures: Membrane Stripping (Membrane Sweeping)
   1. Benefit
      1. Stimulates prostaglandin release
      2. Reduces the need for Labor Induction
         1. Boulvain (1998) Br J Obstet Gynaecol 105:34-40
      3. Useful as adjunct in Labor Induction
         1. Allows for lower overall Oxytocin dose
         2. Foong (2000) Obstet Gynecol 96:539-42
   2. Risk
      1. Unintentional Rupture of Membranes
      2. Infection
      3. Bleeding
   3. Technique
      1. Examining finger inserted into Cervix
      2. Finger moved in circular fashion inside endocervix
      3. Press against internal cervical os
      4. Separates membranes from lower uterine segment
3. Procedures: Methods to apply pressure to endocervix
   1. General
      1. Mechanism: Local pressure releases prostaglandins
      2. Risks
         1. Infection risk with Laminaria
         2. Artificial Rupture of Membranes
         3. Abruptio Placenta
         4. Cervical or uterine bleeding
   2. Hygroscopic Dilator (Laminaria, Lamicel)
      1. Dilator swells with absorption of local fluid
      2. Preparations
         1. Laminaria japonicum (Kelp, natural)
         2. Lamicel (synthetic)
      3. Technique
         1. Outpatient placement of dilator in endocervix
         2. Successive dilators placed until endocervix full
         3. No Fetal Heart Rate monitoring needed
   3. Balloon Dilator (e.g. 16 french Foley Catheter)
      1. Technique
         1. Catheter placed in endocervix
         2. Catheter tip inflated with 30 cc sterile water
         3. Traction applied to catheter
         4. Start Induction when catheter is extruded
      2. Adjuncts
         1. Weight end of catheter
         2. Tug on catheter 2-4 times per hour
         3. Sterile saline infusion
         4. Prostaglandin Gel
      3. Safety
         1. Does not appear to predispose to subsequent PTL
         2. Sciscione (2003) Am J Obstet Gynecol 190:751-4
4. Non-Pharmacologic Methods
   1. Breast stimulation
      1. See Oxytocin Challenge Test
      2. Rigorous trials lacking to show benefit
      3. Theoretical benefit
         1. Breast stimulation stimulates Oxytocin release
         2. Fetal Heart Rate response similar to OCT
      4. Technique
         1. Gentle massage or warm compresses applied to Breast
         2. Done for one hour or repeated three times daily
   2. Sexual Intercourse
      1. Benefits in Cervical Ripening or induction unclear
      2. Theoretical benefit
         1. Female orgasm induces uterine contraction
         2. Semen contain prostaglandins
   3. Acupuncture or TENS unit
      1. Proposed for Oxytocin and prostaglandin release
      2. No rigorous studies to show benefit
5. Alternative Medications: Herbals
   1. General
      1. Used by some nurse-midwives in United States
      2. Anecdotal use in some cultures as long tradition
      3. No current rigorous studies on safety and efficacy
   2. Herbals historically used for Cervical Ripening
      1. Evening Primrose Oil
      2. Black Haw
      3. Black Cohosh
      4. Blue Cohosh
      5. Red raspberry leaves
   3. References
      1. McFarlin (1999) J Nurse Midwifery 44:205-16
6. Disproved Methods that are not recommended
   1. Castor oil
   2. Hot baths
   3. Enemas
7. References
   1. Adair (2000) Clin Obstet Gynecol 43:447-54
   2. Tenore (2003) Am Fam Physician 67(10):2123-8