Labor induction

1. Induction of Labor
M. Kamil

2. Outline
• Definition
• Indication
• Preinduction assessment
• Techniques of induction
• Monitoring during induction
• Complication and side effects of induction

3. Definitions
• Induction of labor:
• Artificial initiation of labor before spontaneous onset for purpose of delivery
of fetus and placenta.
• Success of induction:
• Achieved vaginal delivery.
• Failed induction:
• Failure to generate regular contractions approx. every 3 to 5 minutes and
cervical change after at least 24 hours of oxytocin administration.
• Cervical ripening:
• Use of medications or other means to soften, and dilate the cervix to increase
likelihood of induction success.

4. Indication
Urgent
Elective/ Non-
urgent
Maternal • Worsen of preeclampsia
• Significant maternal disease
• Infection: Chorioamnionitis
• PPROM and PROM
• Isoimmune disease near term
• Postterm
pregnancy
• DM at term
Fetal • Fetal compromise: Marked
oligohydramnios
• Severe IUGR
• Unstable lie (when the lie becomes
stable)
• IUFD

5. Contraindication
• Placenta previa or vasa previa
• Active genital herpes
• Prior classical C- section
• Previous uterine surgery involving full thickness of
myometrium
• Abnormal lie
• Invasive cervical carcinoma
• Category III FHR tracing

6. Types of
cesarean section

7. Preinduction assessment
• Through maternal and fetal condition evaluation
• Indications for and alternatives to the procedure
• Techniques for cervical ripening labor induction
• Explained to the patient

9. American College of Obstetricians and Gynecologists. Patient Safety
Checklist no. 5: scheduling induction of labor. Obstet Gynecol 2011;
118:1473.

10. Techniques
• Preinduction cervical ripening
• Early amniotomy (ARM) as long as the head is engaged
• Oxytocin infusion

11. Bishop score
• Position
• Consistency
• Effacement (%)
• Dilation (cm)
• Station of fetal head

12. Unfavorable cervix
•First step – cervical ripening
•2 options
•Pharmacological
•Mechanical

13. Unfavorable cervix - Pharmacologic option
• Prostaglandin E2
• Many different routes:
• Intracervical (Prepedil)
• Intravaginal (Prostin)
• Intravaginal is better efficacy
• Regime:
• Primigravida: 3 mg
• Multigravida: 1.5 mg
Max: 2 Prostin per day 6 hourly for the first day. The
3rd Prostin inserted early morning of the 2nd day

14. Unfavorable cervix - mechanical options (1)
• A Foley Catheter:
• inserted into the cervix and blown
up with saline

15. Unfavorable cervix - mechanical options (2)
• Hygroscopic mechanical dilator:
• Laminaria
Mechanical options:
• Places where PG is not available
• Concern of uterine hyperstimulation

17. Favorable cervix
1. Artificial rupture of membrane (ARM)
• Study: 2001 systemic review of randomized trials: The combination of
amniotomy plus IV oxytocin was more effective than oxytocin alone.
• Recommendation - to do early ARM during oxytocin induction if fetus is
engaged.
• Other means: “stripping/ sweeping” the amniotic membranes
• Study:2005 meta-analysis of 22 trials: Weekly membrane stripping at term
shortens the time to onset of spontaneous labor and reduces the need for
formal induction.
• Membrane stripping to patients ≥39 weeks of gestation who wish to
accelerate the onset of spontaneous labor.

18. “stripping/ sweeping” the amniotic membranes

19. Favorable cervix
2. Induction of labor by oxytocin
• Start the oxytocin infusion at 2 mill units/ min (12 mL/hr)
• Increase the rate every 30 minutes aiming for 4 contractions in 10
minutes lasting 40 – 90 seconds each.
• Once 4 contractions in 10 minutes are achieved maintain the infusion
rate.

20. Other Oxytocin regimens
• Low dose
• Dose of oxytocin is initiated at 0.5 to 1 milliunits/min and increased by 1
milliunits/min at 30 – 40 minutes intervals
• Slightly higher doses
• Begin at 1 to 2 milliunits/min and increase by 1 to 2 milliunits/min with
shorted incremental time intervals (15 to 30 minutes)
• High dose: Active management of labor regimens, and others, use a
high dose oxytocin infusion with short incremental time intervals.
• Most labor and delivery units do not go above 40 milliunits/min
• Most common complication: uterine tachysystole

21. Monitoring during induction
• Monitoring after PGE2
• Continuous CTG
• Monitor the progress by reassess bishop score:
• 6 hours after vaginal PGE2 tablet or gel insertion OR
• 24 hours after vaginal PGE2 controlled release pessary insertion
• Monitor after oxytocin infusion
• Continuous CTG
• Assess uterine contraction
• Assess the strength of uterine contraction

22. • Tachysystole:
• > 5 contraction in 10 minutes, average over a 30 minutes window
• Uterine hypersystole/hypertonus:
• Contraction lasting at least 2 minutes with a normal FHR
• Must noted: Present/absent of FHR changes.
Complication and side effects
- Abnormal or excessive uterine contractions

23. • Management:
• Perform vaginal examination
• CTG is mandatory to exclude fetal distress
• Flush posterior fornix with NS to remove remaining Prostin
• Oxytocin: discontinue the infusion accompany by FHR changes to back to
normal.
• Place the woman in the left lateral position
• Administer oxygen (10L/min via nonrebreather mask)
• Increase IV fluids (fluid bolus 500 mL of lactated Ringer’s solution or more)
• No prompt response: Administer tocolytic
• SC/IV Terbulatine 250 mcg for fetal resuscitation OR
• IV Atosiban 6.75 mg over 1 min for fetal resuscitation
• For intractable cases: IV nitroglycerin 60 to 90 mcg
Complication and side effects
- Abnormal or excessive uterine contractions (continued)

24. Complication and side effects (continued)
• Failed induction: Failure to establish labor after one cycle of
treatment consisting of:
• The insertion of 2 vaginal PGE2 tablets (3mg) or gel (1-2 mg) at 6 hourly
intervals, OR
• One PGE2 pessary (10 mg) within 24 hours.
• Managements: C/S
• Cord prolapse
• Uterine rupture
• Hyponatremia

25. References
• Coates T. Malpositions of the occiput and malpresentations. In: Marshall J, Raynor M, editors. Myles
textbook for midwives. 16th ed. Edinburgh: Churchill Livingstone Elsevier; 2014. p. 435-54
• Callahan, T., & Caughey, A. (2007). Blueprints obstetrics & gynecology (4th ed. / Tamara L. Callahan, Aaron B.
Caughey. ed., Blueprints). Philadelphia ; London: Lippincott Williams & Wilkins.
• http://www.acog.org/Resources-And-Publications/Patient-Safety-Checklists
• American College of Obstetricians and Gynecologists. Patient Safety Checklist no. 5: scheduling induction of
labor. Obstet Gynecol 2011; 118:1473.
• Porreco RP, Clark SL, Belfort MA, et al. The changing specter of uterine rupture. Am J Obstet Gynecol 2009;
200:269.e1.
• Cunningham, F., & Williams, J. (2014). Williams obstetrics. (24th ed. / [edited by] F. Gary Cunningham et al.
ed.). New York ; London: McGraw-Hill Medical.
• Lilien AA. Oxytocin-induced water intoxication. A report of a maternal death. Obstet Gynecol 1968; 32:171.
• Beckmann, C., Herbert, W., Laube, D., Ling, F., Smith, R., & American College of Obstetricians Gynecologists.
(2014). Obstetrics and gynecology (7th ed.).
• Bilek W, Dorr P. Water intoxication and grand mal seizure due to oxytocin. Can Med Assoc J 1970; 103:379.
• Moen V, Brudin L, Rundgren M, Irestedt L. Hyponatremia complicating labour--rare or unrecognised? A
prospective observational study. BJOG 2009; 116:552.

26. Thank you
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