Cervical Ripening and Induction/Augmentation of Labor

1. Cervical Ripening andInduction/Augmentation of Labor Daren Sachet, RNC/MPA

2. Objectives List the indications and contraindications for cervical ripening and induction of labor. Discuss the different methods used for cervical ripening, labor induction and augmentation. Discuss the nurses role in the safe administration of cervical ripening and induction agents.

3. Definitions What is cervical ripening? Preparation of an unfavorable cervix for labor induction What is induction? Stimulation of uterine contractions before the spontaneous onset of labor What is augmentation? Correcting ineffective uterine contractions or hypocontractility

4. Incidence in the United States National Center for Health Statistics (NCHS) year 2000 data Induction of labor- 19.9% labor augmentation-17.9% National Center for Health Statistics (NCHS) year 2009 data Induction of labor - 22.5% Labor augmentation - 19.9% Since 1989, this represents a 137% increase in induction and a 75% increase in augmentation rates. NCHS, 2009

5. Risk-Benefit Risk of Cesarean Birth for Nulliparous Women: 17.2% spontaneous labor 30.4% induced labor 77.7% increase for induction Reisner et al., 2009 Use of pharmacologic agents increases risk for tachysystole, indeterminate or abnormal FHR patterns and failure to progress

6. Cascade of Interventions Related to Induction of Labor

7. Economic Costs • Spontaneous Labor/vaginal birth $4000 • Induction of labor/vaginal birth $5000 • Cesarean Birth/scheduled $7000 • Cesarean Birth/failed induction $7500 Simpson, KR., 2009 Simpson, 2009

8. Indeterminate/Abnormal FHR(Category II and Category III FHR) • Nearly twice the risk, possibly related to: • Tachysystole • Early Amniotomy • Labor Dystocia • Longer Labor • Less Fetal Tolerance Glantz, 2005, Simpson, KR., 2009

9. Risks to the Infant

10. Indications for Cervical Ripening and Induction of Labor Decrease the rate in patients with elective delivery at 37 to 39 weeks gestation. Joint Commission National Quality Core Measure PC-01

11. Contraindications-Induction of Labor Generally, the contraindications for labor induction are the same as those for spontaneous labor and vaginal birth Vasa previa or complete placenta previa Transverse fetal lie Umbilical cord prolapse Previous transfundal uterine incision Active genital herpes infection Pelvic structural deformities Invasive cervical cancer

12. Situations Requiring Special Attention One or more previous low-transverse cesarean births Breech presentation Maternal heart disease Multifetal pregnancy Polyhydramnios Presenting part above the pelvic inlet Severe hypertension Abnormal FHR patterns requiring emergent birth A trial of labor after a previous cesarean birth or history of prior uterine scar ACOG 2009, 2002

13. Indications for Augmentation of Labor Dystocia Uterine Hypocontractility Uterine hypocontractility should be augmented only after both the maternal pelvis and fetal presentation have been assessed. ACOG 2009

14. Pre-induction/Ripening Criteria Availability of trained nursing and provider staff Cervical ripening agents should be administered at or near the labor and birth suite where uterine activity and FHR can be monitored continually Assessment of gestational age, cervical status, pelvic adequacy, fetal size and presentation A physician capable of performing a cesarean birth should be readily available. ACOG 2009

15. Criteria continued Considerations to any risks to mother or fetus Patient counseling regarding indications, agents/methods, and possibility of repeat induction or cesarean birth The medical record should document that a discussion was held between the pregnant woman and her health care provider ACOG 2009

16. Bishop ScoreHas been shown to be an important determinant of the success or failure of induction

17. Cervical Status Includes documentation of the Bishop score and the presence or absence of uterine activity For women at term, a Bishop score of 6 or more may be useful in predicting onset of spontaneous labor within 7 days Rozenberg, Goffinet & Hessabi, 2000

18. Cervical Ripening Agents These agents may soften the cervix, change the Bishop score Mechanical/Non pharmacologic Methods Laminaria tents Synthetic hygroscopic dilators (Lamicel and Dilapan) Balloon catheters Pharmacologic Methods Prostaglandins (E1 & E2) Oxytocin

19. Mechanical Dilators Laminaria Tents Synthetic Osmotic Dilators Cervical Ripening Balloons

20. Laminaria Tents

21. Synthetic Osmotic Dilators Lamicel Dilapan

22. Balloon Catheters and Extraamniotic Saline Infusion Foley Catheter Extraamniotic saline infusion- balloon catheter Double Balloon Cervical Ripening Catheter Results seen within 8-12 hours after insertion

23. Mechanical Ripening Devices Double balloon device Foley catheter

24. Pharmacologic MethodsNot recommended for use in women with history prior c-birth or uterine scar Prostaglandin E1: Misoprostol (Cytotec) Oral, sublingual or vaginal use Wide variations exist in time of onset of uterine contractions Peak action is approximately 1-2 hours but can be up to 4-6 hours

25. Re-dosing Parameters Re-dosing is permissible if: Still unripe cervix? Happy baby? Redosing is withheld if:

26. Complications with Misoprostol (Cytotech) • Tachysystole • Indeterminate/Abnormal FHR pattern • Precipitous Labors • Uterine Rupture • Need careful maternal/fetal assessments • Need consent/protocols ACOG, 2009

27. Prostaglandin E2-Dinoprostone Prepidil Perform speculum exam, introduce gel just below cervical os Patient should remain recumbent for at least 30 minutes Uterine contractions usually occur within one hour of administration- peak activity within 4 h

28. Prostaglandin E2-Dinoprostone Cervidil

29. Cervical Ripening Agents Minimum safe interval from prostaglandin to oxytocin administration not established Manufacturers guidelines recommend Misoprostol- at least 4 hours after last dose Prepidil- 6-12 hours after last dose Cervidil-30-60 minutes after removal of vaginal insert Not contraindicated with PROM

30. Induction and Augmentation of Labor Mechanical methods of Induction of Labor Stripping the Membranes

31. AmniotomyArtificial rupture of membranes NURSES DO NOT PERFORM AMNIOTOMY

32. Oxytocin Most commonly used induction agent in the United States and worldwide Kelly & Tan, 2001 Synthetic oxytocin is chemically and physiologically identical to endogenous oxytocin Half life between 10-12 minutes Dawood, 1995a; Arias, 2000 3 – 4 half-lives to reach steady state Full effects of oxytocin cannot be determined until steady-state concentration has been achieved. Physiologic steady state 40 min, basis for dosing interval.

33. Endogenous Oxytocin First Stage Labor Maternal circulating concentration 2-4 mU/min Fetal Contribution 3 mU/min Combined effects = 5-7 mU/min Second Stage Labor Surge of oxytocin at Ferguson’s reflex Simpson, KR, 2009

34. Response to Oxytocin

35. Oxytocin Dosing Considerable controversy exists about dosage and rate increase intervals-there is no consensus in the literature

36. Oxytocin Dosing Only increase oxytocin rate if: • FHR is normal • Labor has not progressed 0.5 -1 cm/hr • Contractions are no closer than every 2-3 minutes Excessive uterine activity over the course of 1 hour in first stage of labor is associated with an umbilical artery pH ≤ 7.11 at birth Decrease or discontinue oxytocin in active labor Simpson, KR, 2009

37. Physiologic Dosage Start with doses of 0.5-1 mU/min Increase in 1-2 mU/min increments every 30-40minutes until contractions are every 2-3 minutes apart and labor is progressing ACOG, 1999a, SOGC, 2001 Current literature suggests that 90% of pregnant women at term will have labor successfully induced with 6mU/min or less of oxytocin Dawood, 1995a, 1995b; Seitchik, Amico et al., 1984

38. Oxytocin Administration No maximal dose of oxytocin has been firmly established Doses above 40mU/min are rarely used, except in cases of intrauterine fetal demise (IUFD). Infusion rates >=20mU/min can decrease free water clearance by the kidney resulting in water intoxication. Smith and Merrill, 2006

39. High Dose Oxytocin According to ACOG (2009), protocols that involve “high-dose” oxytocin are acceptable; however, high-dose oxytocin is associated with more uterine tachysystole SOGC recommends using the minimum dose to achieve active labor, increasing the dosage no more frequently than every 30 minutes and reevaluating the clinical situation if the oxytocin dosage rate reaches 20 mU/min

40. Oxytocin and Medication Safety

41. Nursing responsibilities Titrate oxytocin infusion drip to achieve three contractions in 10 minutes with a duration of 60-90 seconds Closely monitor fetal response, uterine activity and resting tone Monitor maternal vital signs and fluid balance

42. Potential Complications-Oxytocin Tachysystole Abruptio placentae Uterine rupture Hyponatremia (water intoxicaiton)

43. Nursing Interventions for Tachysystole with Normal FHR pattern Lateral positioning of mother Increase IV fluid (LR) If uterine activity not returned to normal after 10 minutes,  oxytocin by half If tachysystole persists, D/C oxytocin until tachysystole resolves Consider terbutaline 0.25 mg SQ, with order ACOG, 2010, AWHONN, 2008

44. Nursing Interventions for Tachysystole with Indeterminate or Abnormal FHR pattern Discontinue or reduce oxytocin Lateral positioning of Mother IV fluid bolus (LR) If hypotensive, (as with epidural) contact anesthesia provider, prepare to administer epinephrine, with order Oxygen, 10 LPM, non-rebreather mask Consider terbutaline 0.25 SQ, with order If unresolved, inform provider immediately, possibly prepare for C/S. (ACOG 2010)

45. Resuming Oxytocin

46. Women attempting VBAC Should women with a previous cesarean birth undergo induction or augmentation of labor? Spontaneous labor more likely to result in successful VBAC Some studies show women with oxytocin administration undergoing TOLAC may be at increased risk of uterine rupture than spontaneous labor. Other studies have not. Use of prostaglandins are associated with a higher rate of uterine rupture and are NOT RECOMMENDED ACOG, 2010

47. VBAC Success Rates

48. VBAC Induction • Physician and surgical team must be immediately available throughout active labor • Recommend 1:1 nursing care with an experienced RN • Continuous EFM • Must have ability to perform emergency C/birth

49. Nursing Implications with VBAC Induction/Augmentation Access to operating room readily available Monitor as for high risk Signs and symptoms of uterine rupture/dehiscence of prior scar Patient c/o increasing pain and tenderness even with epidural Presentation may take place over period of time or suddenly like “something has given away” Vomiting, syncope, vaginal bleeding, tachycardia, fetal bradycardia or absent fetal heart rate

50. Management Maternal stabilization and immediate cesarean birth Key to diagnosis is suspicion of uterine rupture Simpson, K.R & Creehan, P., 2001