Induction of labour

Induction of labour

Main and The Obgyn Clinic of Hvidovre (danish)

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Preterm Labor with Intact Membranes

PROM (Premature Rupture of Membranes)

PPROM (Preterm Premature Rupture of Membranes )

Is made once a continuation of pregnancy might impair risk for mother and/or fetus and there is no contraindication for vaginal delivery. The pregnancy should end within a reasonable time, if not, cesarean section should be normally performed.

Indication:

In normal pregnancies after 41 weeks. Some (Denmark) recommend 42 weeks. This routine induction of labour at 42 weeks has recently been questioned in a readable article. SM Menticoglou, PF Hall, 2002.
Severe hypertension, (systolic: = 170 - diastolic: = 110)
Diabetes prior to the estimated date of delivery.
Abruptio and/or fetal distress in case Cesarean section are not indicated.
Intrauterine growth retardation.
Pre- rupture of membranes after 34 weeks.
Isoimmunization
Chorioamnionitis
Intrauterine death (coagulopathy first after more than 4 weeks)

Contraindications:

Severe fetal distress
Placenta or vasa praevia
Previous uterine surgery, myomectomy in case the uterine cavity has been opened
Classical uterine incission
Feto-pelvic disproportion
Grand multipara is a relative contraindication
Transvere lie
Previous Cesarean section more than 1. In selected cases, woman can deliver after 2 previous Cesarean section.
Some maternal cardiac conditions

Risks:

Tonic contraction
Hypertonus
Fetal distress especially in compromised fetus
Uterine rupture (multiparas, scarred, titanic contraction).
Water intoxication.

Induction: Fetal wellbeing should be established controlled prior to induction

Care During:
Continuous electronic fetal monitoring during oxytocin infusion, and after prostaglandin contraction.
Uterine hyper-contractility, single contraction lasting < 2 minutes or contraction frequency of 5 or more in 10 minutes. Oxytocin should be decreased or discontinued
Uterine tocolysis should be considered especially in the presence of abnormal fetal heart rate (FHR)
Suggested regime is subcutaneous Terbutaline 0.25 mg or Nitroglycerin resoriblet 0,25 mg or 0,4 mg sublingual or as nasal spray as required. Possible soon delivery, eventually by cesarean section.

Methods of Induction:
Prior to formal induction of labour, women should be offered sweeping of the membranes which reduce duration of pregnancy with 3 days. (increase level of discomfort, no increase of infection risk, and may facilitate the induction).

Prostaglandin should be used in preference to Oxytocin when induction is undertaken with intact membrane regardless of the cervical favorability.

Either Oxytocin or Prostaglandin (PG) may be used when induction of is undertaken in women who have rupture of membranes, as they are equally effective.
Intravaginal Prostaglin E2 seems to be as effective as intracervical Prostaglandin but less invasive. Uterine hyper-contractility with a fetal heart rate is reduced with the use of vaginal gel formulation in comparison with suppositories but they are equal effective.

Prostaglin E2 in sustained released form, should be removed at the onset of hyper stimulation.

Vaginal Prostaglandin 3 mg PGE2, 6-8 hourly, maximum doses 2 tablets for all women.

PGE2 gels, 2 mg PGE2 for nulliparous with Bishop <4,(see later) all other patients 1 mg dose to be repeated 6 hours later. Maximum dose 4 mg PGE2. For nulliparous women with an unfavorable cervix and 3 mg for all other women.

Misoprostol (PGE1) 25 mg repeated after 6 hours has been reported superior or as effective as PGE2 gel. Doses up to 25 mg 4 hours up to 6 times has been reported. Because of lack of experience many do not use it in case of previous Cesarean section.

Comparing misoprostol 50 µg and 25 µg there seems to be more hyperstimulation and Cesarean section (C/S) caused by fetal distress but less C/S because of dystocia, less intrusmental vaginal delivery and sphicterupture than in the low dose regime.

A recently study has shown that titrated oral misoprostol was associated with a lower incidence of uterine hyperstimulation and lower Caesarian delivery rate than vaginal misoprostol 25 mg every 4 hour for induction in women with unfavourable cervix. Misoprostol was given as 20 mg per hour in the first 4 hours. After 4 hours the dose was increased to 40 mg and after further 4 hours the dose was increased to 60 mg.

Oxytocin (in the presence Oxytocin should not be started before 4-6 hours following PGE2 administration or 30-60 minutes after removal of Prostaglandin in sustained-release form.

Induction with Oxytocin:

Treatment Regimes:

Time after starting (minutes)	Dose Oxitocin infusion (milliunits/minute)
0	1
30	2
60	4
90	8
120	12
150	16

Modified Bishop's score

Cervical feature \ Pelvic score	0	1	2	3
Dilatation (cm)	< 1	1-2	2-4	> 4
Length of cervix (cm)	> 4	2-4	1-2	< 1
Station (relative to ischial spines)	-3	-2	-1/0	+1/+2
Consistency	Firm	Average	Soft	-
Position	Posterior	Mid/Anterior	-	-

References
(1) Andresen DM, Jensen JS, Ulbjerg N. Misoprostol-a safe preparation for induction of labour. Ugeskr Laeger, 206 Oct 23;168(43): 3711-4.

(2) Cheng SY, Ming H, Lee JC. Titrated oral compared with vaginal misoprostol for induction: a randomized controlled trial.. Obstet Gynecol, 2008 Jan;111(1):119-25

(3) Induction of labour. RCOG Evidence-based Clinical Guideline No. 9, June 2001.

(4) MacLean A., et al. Infection and Pregnancy, RCOG Press 2001.

(5) Savas M. Menticoglou, Philip F. Hall. Routine induction of labour at 41 weeks gestation: nonsensus consensus. British Journal of Obstetrics and Gynecology 2002; 109:485-491.

(6) Tan BP, et al. Prostaglandins versus oxytocin for prerupture of membranes at or near term. Cochrane Database Syut Rev 2001;Issue 2