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Cervical Ripening. Dr Jessica Servey, FAAFP 15 March 2007 Travis AFB Family Medicine Residency. Review the indications for cervical ripening Review the mechanical means of cervical ripening Look at pharmacologic for cervical ripening Consider risks and benefits of agents. Objectives.
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Cervical Ripening Dr Jessica Servey, FAAFP 15 March 2007 Travis AFB Family Medicine Residency
Review the indications for cervical ripening Review the mechanical means of cervical ripening Look at pharmacologic for cervical ripening Consider risks and benefits of agents Objectives
What is cervical ripening • Process that is used to soften, dilate and efface the cervix • Agents will often start labor
Indications • Postterm • Hypertensive disorders • Premature rupture of membranes • Chorioamnionitis • IUGR • Isoimmunization • Intrauterine fetal death • Maternal medical complications • Logistic factors
ABSOLUTE Placenta previa Vasa Previa Transverse/breech lie Prolapsed cord Prior classical c-section Active genital herpes RELATIVE Multifetal gestation Polyhydramnios Maternal cardiac conditions Grand multiparity Presenting part not in fetal pelvis Contraindications
Bishop score • Described 1955 • Score at least 8 – induction chances of vaginal delivery • equivalent to spontaneous • ACOG recommends score at least 6 for induction
Methods to ripen • Mechanical • Laminaria • Dilators • Foley balloon • Membrane stripping • Acupuncture • Pharmacologic • Prostaglandin (Prepidil/Cervidil) • Misoprostol • Pitocin
Mechanical Methods • Laminaria • Efficacious in cervical dilation • Increased risk of intrauterine infection third trimester • Hygroscopic cervical dilators • Cheap • Easy to place
Mechanical Methods • Membrane stripping • Cochrane review of 19 trials, 17 compared with placebo • NNT 7 to avoid one formal induction past 40 weeks • No risk of infection • Acupuncture • LI4 and Sp6 can aid in cervical ripening • Study demonstrated shortened interval to delivery
Foley balloon • First described in 1967 • Safe • Cheap • Easy to use in combination with pitocin • May be useful for outpatient ripening
Foley Balloon • 2004 (30 vs 80 ml) • 75% in 80ml group vs 58% in 30ml deliver within 24 hours • c-section rate not significant • 2005 (extra amniotic saline infusion) • No difference in vaginal delivery rates • No difference in maternal or fetal complications
Cervidil/Prepidil • PGE2 • 3 methods of action • Alters extracellular ground substance • Affects smooth muscle of the cervix • Gap junction formation • Meta analysis of more than 7 studies show efficacy compared to placebo or oxytocin • Storage/cost/user capability are issues
Cervidil Placed in posterior vaginal fornix Prepidil Intracervical placement
Low dose pitocin • 1 to 4 mu per minute for ripening • 2002 study compared this to cytotec 50 ucg dose • Interval to delivery - significantly less with cytotec • Vaginal delivery – 61% vs 65% (no difference) • Cytotec higher c-s for fetal distress (27% vs 8%) • Pitocin higher c-s for labor dysfunction (26 vs 10%) • Overall- same efficacy
Misoprostol • Dosing • 25 mcg • 50 mcg • Intravaginal • Oral • Very cheap • Easy to store • NOT FDA APPROVED
Misprostol 25 vs 50 ucg dose • 50 ucg increase rate of vaginal delivery • Shorter time to delivery • Increased fetal distress related to uterine hyperstimulus • Cochrane review with increased need for oxytocin with 25 but less uterine problems (NNT 25) and trend toward less neonatal ICU admissions • Individual studies show differences in c-section rates
Oral vs vaginal • Study published 2005 • 212 women • No statistical difference between time of first dose to time of delivery • Pitocin used in 97% of both groups • No difference in maternal complications, fetal complications, or side effects • No difference in indication for c-section • Dosing: • 25 ucg vaginally every 4 hours vs 50 ucg followed by 100 ucg orally every 4 hours
Which is better? • Study 2003 Cervidil vs cytotec (both had pitocin) • Time to vaginal delivery not significant • C-section rate not significant • Reasons for c-section essentially the same • Cochrane review • Subgroup analysis with significantly larger % of patient deliver within 24 hr with cytotec (nnt 10) • No change in c-section rate for PGE1 vs 2
How to choose? • Cost effectiveness • Cervidil and prepidil vs cytotec and Foley balloon • Cost of nursing staff • ? Outpatient regimens • How long must use pitocin • Patient choice • Only safety contraindication—Prior c-section • Increased risk of uterine rupture using prostaglandins to ripen cervix for VBAC
References • Colon et al, Prospective Randomized Clinical Trial of inpatient cervical ripening with stepwise oral misoprostol vs vaginal misoprostol, American Journal of Obstetrics and Gynecology, 2005, 192:747-752. • Cochrane database, Membrane sweeping for induction of labor, updated 2005. • Levy et al, A randomized trial comparing a 30-ml and a 80-ml Foley catheter balloon for preinduction cervical ripening, American Journal of Obstetrics and Gynecology, 2004, 191:1632-1636. • Bolnick et al, Randomized trial between two active labor management protocols in the presence of an unfavorable cervix, American Journal of Obstetrics and Gynecology, 2004;124-128. • Weaver, Sally,Vaginal Misoprostol for Cervical Ripening in Term Pregnancy, American Family Physician, February 2006, Vol 73;3, pg 511-512. • ACOG Committee on Practice Bulletin-Obstetrics. Induction of Labor. ACOG Practice Bulletin No. 10., November 1999. Obstetrics and Gynecology. 1999:94(part1) 1-10. • Lydon-Rochelle et al, Risk of uterine rupture during labor among women with prior cesarean delivery, New England Journal of Medicine, 2001, 345;3-8. • Sanchez-Ramos, Luis, Induction of Labor, Obstetrics and Gynecology Clinics of North America, 2005, 32;181-200.