INDUCTION ANDAUGMENTATION OF

LABOURDr. Jograjiya

Post Graduate Student, Department of Gynaecology and Obstetrics

PGIMSR, ESIC, Basaidarapur, New Delhi

Artificial stimulation of uterine contractions with or without ruptured membranes at any time after the 28th week of gestation by method that aims to secure a normal vaginal delivery before the spontaneous onset of labor. • Deferred until after the 36th week. • Without any acceptable medical or obstetric indication.

Augmentation refers to stimulation of spontaneous contractions that are considered inadequate because of failed cervical dilation and fetal descent.

DEFINITION

To eliminate the potential risks to the fetus with prolonged intrauterine existence while minimizing the likelihood of operative delivery

Increasing trend globally. According to the National Center for Health Statistics

90 per 1,000 live births in 1989 184 per 1,000 live births in 1997 (1).

The incidence of induction varies widely 5-30%.

GOAL AND INCIDENCE

Maternal IUD Fetal malformations PolyhydramniosiosFetal Postdated pregnancy Intrauterine growth restriction

(IUGR) Rh isoimmunization Unexplained IUD in prior

pregnancy Diabetes Mellitus

Combined Hypertensive disorders of

pregnancy Chronic renal disease and

essential hypertension, chronic pulmonary disease

Premature rupture of membranes Chorioamnionitis Abruptio placentae incompatible with life

INDICATION

Major degree of Placenta praevia Major degree of cephalopelvic disproportion Vasa praevia Previous classical uterine incision Cephalopelvic disproportion because of malpresentation or

abnormal pelvic bone structure Active genital Herpes infection Invasive cervical carcinoma Hypersensitivity to cervical ripening agents Transverse lie

Contraindications

Multiple pregnancy Polyhydramnios Grand multiparity Maternal heart disease Severe hypertension Breech presentation One or more previous cesarean section Abnormal fetal heart rate not requiring emergency cesarean

section

Conditions where IOL is not a true contraindication but where special caution is

required

Maternal Risks : o Failure leading to Cesarean sectiono Intrauterine infection, Chorioamnionitiso Increased risk of post partum hemorrhage

due to Uterine Atonyo Uterine hyperstimulation o Rupture uterus o Amniotic Fluid Embolism o Precipitate labor , Dysfunctional labor o Increased risk of operative vaginal delivery o Abruptio Placentae o APH from undiagnosed placenta praevia o Water intoxication

RisksFetal Risks : o Fetal distresso Fetal death o Neonatal sepsis o Iatrogenic

delivery of a preterm infant

o Cord prolapse o Neonatal

jaundice o Increased risk of

birth trauma

₤ Evaluate the indication ₤ Explain the indication of induction to the patient along with details of the

method to be used and take a written informed consent ₤ Assess adequacy of the pelvis and fetal size to r/o CPD₤ Confirm the gestational age, fetal lie, and assess the fetal lung maturity # where

ever indicated ₤ Uterine activity and fetal heart rate should be continuously monitored. In case

of clinical auscultation, FHR should be heard during and for 1 minute after a contraction at least every 15 minutes during the active phase of labor and after every contraction in the second stage . Otherwise electronic fetal monitoring is preferable Partogram is to be maintained for active labour Trained personnel and well equipped center

Pre- requisites for IOL:

# According to the ACOG Committee Opinion (2) , if one of the following criteria are met then fetal maturity may be assumed and amniocentesis need not be performed to confirm fetal maturity: € It has been 36 weeks since a positive serum or urine human

chorionic gonadotropin pregnancy test was performed by a reliable method

€ An ultrasound measurement of the crown rump length, obtained at 6-11 weeks, supports a gestational age of 39 weeks or more

€ An ultrasound scan obtained at 12 to 20 weeks confirms the gestational age of 39 weeks or more determined by clinical history and physical examination

The uterine cervix has broadly two components which are:a) cellular portion and, b) extracellular matrix The distal portion has greater connective tissue as compared to the part close to the myometrium which is richer in the cellular component. The cellular component has: smooth muscle cells, fibroblasts, epithelium, and blood vessels. Cervical stromal cells produce collagenases, elastases and metalloproteinaeses which are involved in remodeling of the cervix. Fibroblasts also secrete cytokines like interleukin 1 beta and interleukin -8

Structures and Physiology of cervical ripening :

collagen is in two forms Type I (70%) and type II (30%) and is arranged in the form of a triple helix. In the non pregnant cervix these are arranged in a dense and irregular fashion these fibres are arranged parallel to and between the collageAn fibres and play an important role in taking the pregnancy to term by keeping the os closed is a glycosaminoglycan and its relative proportion to collagen is important in the remodeling of the cervix at labor. is the most important proteoglycan which is responsible for the increased water content of the cervix.

Extracellular matrix

a) Collagen:

b) Elastin:

c) Decorin:

d)Hyaluronic acid:

Collagen is reorganized and consolidated in early pregnancy with proliferation and hyperplasia of the cellular component

Near the onset of labor, an overall decrease in the concentration of collagen occurs with dispersion and remodeling into fine fibers, making the cervix softer in consistency

Increases in decorin levels and physiologic cell death are in part responsible for this process

Hyaluronic acid levels increase thereby increasing the water content of the cervix and causes a loosening and dispersal of the fibers

Chemotactic response at term leads to an influx of neutrophils and an increased levels of cyokines (interleukin 1 beta and interleukin –8 ) which in turn release collagenases and elastases to allow effacement

Mechanical forces of uterine contractions extend the elastin and allow dilatation

Changes during pregnancy:

PRE INDUCTION CERVICAL ASSESSMENT

It is known that success of labor induction is closely related to ripeness of the cervix . Various scores have been proposed to evaluate the cervical status. a) Bishop’s Score : This was proposed by Bishop in 1964 (3) and is the most widely used score. It was originally proposed to determine the suitability of a patient for IOL in patients who were parous, at term , had an uncomplicated pregnancy and the fetus was in cephalic presentation.

Assessing Favor ability for Induction of labour

* A score of 9 or more ensured a safe and uniformly successful induction

Bishop ScoreFactor/Score

0

1

2 3

Dilatation (cm) 0 1-2 3-4 5-6

Effacement(%) 0-30 40-60 60-70 80+

Station (cm) -3 -2 -1/0 +1/+2Consistency Firm Medium Soft -

Position Posterior Mid-posterior Anterior -

* Induction with a score of 16 more is considered favorable

Burnett (5) later on modified the original Bishop’s score giving a maximum score of 2 to each of Bishop's five categories, giving a total maximum score of 10.

He considered effacement in terms of length and not percentage and considered previous term birth and cephalic presentation to be pre-requisites for induction.

* Outcome of patients with a score of less than 6 was unfavorable, with a score of 9- 10 all patients could be delivered within 4 hours and most within 24 hours.

Modified ‘Bishop’ ScoreFactor/Score

0

1

2

3

Dilatation (cm) <1 1-2 2-4 >4

Cervical length (cm) >4 2-4 1-2 <1Station (cm) -3 -2 -1/0 +1/+2Consistency Firm Moderate Soft -

Position Posterior Mid; Anterior - -

Evaluating the performance of Bishop's score, Lange et al (6) observed that cervical dilatation was twice as important as the other factors and proposed a modification of the original score which predicted successful induction equally well.

Table 4. Pelvic Score Proposed by Lange et al

Factor/Score

0

1

2

3 Multiply by

Dilatation (cm) 0 1-2 3-4 5+ ×2Cervical length

(cm) 3 2 1 <1 ×1

Station (cm) -3 -2 -1 or 0 +1 or +2 ×1

MECHANISM OF INITIATION OF LABOR

Mechanism (continued)

ENDOCRINOLOGY OF LABOR

TIME, PLACE & PREPARATION

Preferably early morning

Where facility for intervention and fetal monitoring is available

Enema may be given to patients prior to induction

Time of induction:

Place of induction:

Preparation of Patient :

Membrane Sweeping

Prostaglandins

Amniotomy

Oxytocin

Methods of induction of labor

hygroscopic dilators, osmotic dilators (Laminaria japonicum), Foley catheters,

double balloon devices, and extraamniotic saline infusion.

Methods of induction of labor

Risks Risks

If pregnancy continues If pregnancy interrupted

MEMBRANE SWEEPING¤ Its possible only if the cervix

has ripened to allow the passage of one finger.

¤ Insertion of a gloved finger through the cervix and it’s rotation against the wall of the uterus.

¤ Its strips off the chorionic membrane from the underlying decidua releases PGS

¤ Placenta Previa should be excluded, Accidental amniotomy is a disadvantage.

Cervical ripening before labor induction in an unfavorable cervix increases the success rates and shortens the induction to delivery interval. ᶲ Pharmacological methods (Prostaglandins, Oxytocin &

others)

ᶲ Non pharmacological methods (Natural, Surgical, Mechanical and others)

CERVICAL RIPENING

PG E2 gel has been widely used for pre-induction cervical ripening. Local applications of PGE2 causes cervical ripening by three mechanisms:♦ Alteration of extracellular grounds substance of cervix by

increasing collagenase, elastase, glycosaminoglycans, dermatan sulfate, and hyaluronic acid levels

♦ Relaxation of smooth muscle of cervix ♦ Gap junction formation leading to initiation of uterine

contractions

PROSTAGLANDINS

Intracervical PGE2 gel: ( Cervigel , Dinoripe , Prepidil ) Contains 0.5 mg of PGE2 Bring the gel to room temperature before use and instill in the

cervical canal below the internal os The patient lies supine for 15-30 minutes after the insertion . If no response occurs in one use a repeat insertion may be required

after 6 hours Maximum of 1.5 mg or three insertions are allowed over a period

of 24 hours. If required oxytocin is to used only after 6- 12 hours of the last

insertion.

Preparations available, Dosage and Usage Guidelines

Vaginal PGE2 gel : contains 2.5 mg PGE2 2 doses 6 hours apart are used

Vaginal controlled release insert : (Cervidil )

10 mg insert which releases 0.3 mg / hr of the prostaglandin. No need to pre warm the insert. The patient should lie supine for 2 hours following the insertion. The insert is to be removed after 12 hours or when active labor

begins or in case of hyperstimulation.

Intravaginal PGE2 gel

Intracervical use is technically more difficult Vaginal route ( gel or insert ) is superior to intracervical route for

cervical ripening but it causes higher uterine activity Controlled release vaginal insert use gives a better post ripening score,

decreased the time to delivery, time to active labor and need for oxytocin use as compared to vaginal gel 2 doses 2.5 mg six hours apart.

The overall incidence of hyperstimulation is 4.8% - same as with oxytocin. However , the incidence is more when used in active labor (12.5 %) , more with vaginal gel (5%) than intracervical (1%) and least with controlled release insert which can be reversed with terbutaline administration or removal of the vaginal insert. Washing the vagina does not offer any benefit

Use of PGE 2 does not alter C. S. rates

PGE 2 Routes : Controlled trials : Some observations

CONTRAINDICATIONS Established uterine activity Glaucoma Asthma Severe hepatic impairment Severe renal impairment Known hypersensitivity to prostaglandins , Active vaginal bleeding

Side Effects

Uterine tachysystole has been reported to follow vaginally administered prostaglandin E2 in 1 to 5 percent of women . Although definitions may vary among studies, most use the terms defined by the American College of Obstetricians and Gynecologists (1999a) to describe increased uterine activity as follows:1.Uterine tachysystole is defined as 6 contractions in a 10-minute period.2.Uterine hypertonus is described as a single contraction lasting longer than 2 minutes.3.Uterine hyperstimulation is when either condition leads to a nonreassuring fetal heart rate pattern.Because hyperstimulation that can cause fetal compromise may develop when prostaglandins are used with preexisting spontaneous labor, such use is not recommended. If hyperstimulation occurs with the 10-mg insert, its removal by pulling on the tail of the surrounding net sac will usually reverse this effect. Irrigation to remove the gel preparation has not been helpful.

ACOG Guidelines : (14,15) Bishop’s score should be less than 4. Drug should be administered near the delivery suite. Patient should lie recumbent for 30 minutes after the

instillation. FHR and uterine activity should be monitored for 30

minutes to 2 hours after the instillation. After this, patient may be transferred elsewhere, if there is no increase in uterine activity and FHR is normal.

The controlled release insert should be removed at the onset of labor.

Oxytocin should be avoided for initial 6-12 hours.

RCOG Guidelines : (16) Intravaginal PGE2 should be used in preference to

intracervical preparations as they are equally effective and administration of intravaginal PGE 2 is less invasive of the vaginal preparations.

Tablets should be preferred over the gel as they are more cheap and equally effective.

MISOPROSTOL

Mioprostol is a synthetic PG E1 analogue which has been used as a gastric cytoprotective agent since 1988 for patients of peptic ulcer.

Studies in late 1980’s and early 1990’s noted that oral administration of this drug causes uterine contractions in early pregnancy. Subsequent studies showed that intravaginal misoprostol causes first and second trimester abortion and there has been recent evidence of its use for cervical ripening and labor induction.

Pharmacokinetics: The pharmacokinetics of misoprostol have been extensively studied by Ziemann et al (17).

₵ They have observed that peak plasma concentration is higher and achieved earlier after an oral administration.

₵ Peak levels with vaginal administration are attained more slowly and sustained for longer periods because of the presystemic gastrointestinal and hepatic metabolism that occurs with oral route.

₵ Overall the systemic bioavailability is three times higher with the vaginal route.

Dosage schedules and usage guidelines: ⱷ Cheap drug ⱷ Does not require storage conditions ⱷ Can be given by oral, buccal or vaginal routes although

vaginal route is the most extensively used ⱷ Tablets are available as either 100 mcg or 200 mcg ⱷ Dosage: 25 –50 mcg is administered 4-6 hourly ⱷ The tablet is inserted into the posterior vaginal fornix ,

one may or may not wet the tablet with saline prior to insertion

Misoprostol : Controlled trials : some observations: (18) Ʃ Oral route is not recommended at this point of time Ʃ Misoprostol shortens the Induction delivery interval as compared to PG

E2 and oxytocin Ʃ 25 mcg vaginal dose has less hyperstimulation but a longer IDI as

compared to 50 mcg Ʃ It effectively lowers the cesarean rates Ʃ However it is not recommended as an outpatient setting or with previous

C. S. Ʃ An increase in the incidence of meconium staining of amiotic fliud and

tachysystole is noted Ʃ Overall the use of misoprostol is not associated with an increased rate of

operative intervention for fetal distress and NICU admission.

ACOG Guidelines Ω 25mcg should be the initial dose for labor induction at term,

should not be administered more frequent than 3-6 hours, oxytocin should not be administered < 4 hours after the last misoprostol use and the drug should be avoided in patients with previous cesarean delivery or major uterine surgery.

Ω Use of higher dosage 50 mcg may be appropriate in some situations and have a greater likelihood of vaginal delivery within 12 hours, such doses increase the risk of hyperstimulation and rupture.

Ω There is at present insufficient clinical evidence to address the safety of misoprostol in patients with multiple gestations and suspected fetal macrosomia.

RCOG Guidelines : (16) Misoprostol appears to be more effective than oxytocin or vaginal PG E2 in presence of ruptured membranes for induction of labor.

Use of misoprostol in obstetrics must be restricted to RCTs.

Oral misoprostol appears to be less effective than vaginal misoprostol, however, oral route is associated with less incidence of uterine hypercontractility but a higher incidence of meconium stained liquor.

Its use is associated with increased uterine hypercontractilty but this is not translated in increased operative delivery rates. The safety issues surrounding the use of misoprostol have not been clearly evaluated. * Despite a lot of clinical use, misoprostol is still not approved by the Drug Controller of India for use in induction of labor.

OTHER PHARMACOLOGICAL METHODS

Mifepristone: 200 mg misoprostone for 2 days has been recently used for cervical priming (23). However this method is not cost effective and needs further trials.Relaxin: Relaxin has been demonstrated to causes changes in the collagen resulting in cervical softening . Both purified porcine and DNA produced human relaxin have been tried with success in promoting cervical ripening with no adverse maternal and fetal outcomes (24,25) . It is not yet commercially available. Nitric Oxide: Animal studies have shown it to be a cervical ripening agent but it is unlikely to be used for human use unless safety of NO in late pregnancy is establishedCytokines: Theses are chemotactic agents which also can promote cervical ripening by causing changes in the extracelllulaar matrix

NON PHARMACOLOGIC APPROACHES TO CERVICAL PRIMING AND LABOR INDUCTION: (Natural, Surgical, Mechanical and others):NATURAL MODALITIES: a) Herbal supplements: Commonly used herbal cervical ripening agents include evening primrose oil, black cohosh, raspberry leaves. The liquid of black cohosh is given as 10 drops sublingually hourly until the cervical change occurs. Evening primrose oil is given as 3 capsules orally daily for one week, this can be repeated for three such administrations. red raspberry leaves also enhance uterine contractions in a synchronous manner b) Intercourse: results in a 10-50 fold increase in cervical mucus prostaglandin concentrations which occurs after 2-4 hours and remains for more than 12 hours duration. There is an associated increase in the uterine contractile activity.

Hygroscopic dilators: These are natural or synthetic rods inserted through the cervical os and left in situ for a particular time wherein because of their osmotic properties they absorb endocervical and local tissue fluids . This swelling causes a controlled dilatation of the cervix along with releasing prostaglandins. Natural dilators are obtained from the seaweed Laminaria japonicum. Balloon devices : Foley’s catheter or designer balloon devices when inserted intracervically can facilitate cervical ripening. Once properly placed ( beyond the internal os) balloon or the catheter is inflated with 30-50 ml saline. It is recommended to either attach a defined weight to the catheter end ( 1litre of i.v. fliud ) or to use “gentle tugs” – 2 to 4 each hour until the catheter or the balloon passes out (26,27) . Some recommend infusion of extra-amniotic saline at the rate of 1 cc/minute. There is no infection associated with balloon devices

MECHANICAL MODALITIES

Mechanical -- Double balloon

Ideally amniotomy or ARM is performed when the cervix is effaced and 2 cm dilated but it can be performed with minimal cervical dilatation. Methodology of ARM:ψ Auscultate the FHR ψ Evaluate the cervix and station of head. The cervix should be well

applied to the head ψ Introduce two fingers into the cervix , sweep away the membranes

from the cervix ψ Pass an Hook or Kocher’s forceps in between the groove of your two

fingers , hook the membranes and rupture them; look for the clarity of liquor

AMNIOTOMY

Stretching of the cervix & separation of the membranes Release of Prostaglandins Depends on the state of the cervix and station of the presenting part

MECHANISM OF ACTION

CONTRAINDICATIONS:

IUD Placenta praeviaMaternal HIV Genital active herpes

infection

HAZARDS:Cord prolapseAmnionitisAmniotic fluid

embolismAbruptio placentaeBleeding through vasa

praeviaMaternal and fetal

infection Fetal injury

ADVANTAGES: It shortens duration of laborAllows for early diagnosis of meconium staining of

amniotic fluid, specially in high risk pregnancyFacilitates invasive fetal monitoring Newer

amnicot

OXYTOCIN A polypeptide hormone Secreted by the posterior pituitary gland The drug was used intravenously in 1948 by Theobald et al (21) to

induce labor. Later in 1958 Du Vigneaud et al (22) synthesized the drug. Since then it has been the most commonly used drug for induction

and augmentation of labor.Routes of administration: Intravenous route being the most widely used. It can be absorbed from the nasal or buccal mucosa, however when given orally it is rapidly inactivated by trypsin.

The half life of oxytocin is 3-5 minutes. Once absorbed it is distributed in the extracellular fluid and does not bind to plasma proteins and is excreted by the liver and kidneys. The action is mediated by oxytocin receptors (OTR) which are present on the myometrium.

Myometrial response to oxytocin begins at 20 weeks , increases through out pregnancy and peaks just before initiation of labor.

The response varies according to the status of the cervix, uterine sensitivity, variability in oxytocin clearance rate, duration of pregnancy and the pre-existing myometrial contractions.

The OTR concentration is the rate limiting step for oxytocin action. Oxytocin on binding to the OTR increases the intracellular concentration of calcium causing myometrial cell contraction. Uterine contractions are also stimulated by a calcium independent mechanism involving the prostaglandins. PGE and PGF are increased during oxytocin administration. It has been postulated that Prostaglandin release by oxytocin is necessary for fully efficient uterine contractions during labor.

PHARMACOKINETICS AND MECHANISM OF ACTION

Various Low- and High-Dose Oxytocin Regimens Used for Labor Induction

Regimen Starting Dose (mU/min)

Incremental Increase (mU/min) Interval (min)

Low-Dose 0.5–1.5 1 15–40

2 4, 8, 12, 16, 20 25, 30 15

High-Dose 4 4 15 4.5 4.5 15–30 6 6* 20–40@

DOSING AND USAGE GUIDELINES: 10 –20 units are dissolved in 1000 ml of balanced salt solution ( Ringer Lactate solution or Normal saline ) making it as 10-20 mu/ml and it is preferable to give it through an infusion pump. Further increments are made according to the low dose or high dose protocol given below (15 ) :

*With hyperstimulation and after oxytocin infusion is discontinued, it is restarted at 1/2 the previous dose and increased at 3 mU/min incremental doses.@Hyperstimulation is more common with shorter intervals.

After intravenous infusion, uterine response occurs within 3-5 minutes and a steady state plasma concentration is reached in about 40 minutes.

The end point to be achieved is uterine contractions every 2- 3 minutes lasting for 60-90 seconds and a uterine pressure of 50- 60 mm Hg or 150 Montevideo units.

Hyperstimulation , with or without fetal heart rate changes

Failed induction with need for repeat induction or possibly cesarean

Increased risk for uterine rupture in some studies Hypotension if administered by IV bolus Hyponatremia if administered with large amounts of

sodium poor fluids Antidiuretic hormone like effect if administered at high

doses Increased risk for neonatal hyperbilirubinemia

RISKS OF OXYTOCIN

In the management of active-phase arrest, and with no contraindication to intravenous oxytocin, decisions must be made with knowledge of the safe upper range of uterine activity.

Importantly, despite no labor progression, there were no adverse maternal or perinatal effects in those undergoing cesarean delivery.

There are no data regarding safety and efficacy of contraction patterns in women with a prior cesarean delivery, with twins, or with an overdistended uterus.

First-stage arrest of labor is defined by the American College of Obstetricians and Gynecologists (1989, 1995a) as a completed latent phase along with contractions exceeding 200 Montevideo units for more than 2 hours without cervical change. Some investigators have attempted to define a more accurate duration for active-phase arrest.

Duration of Oxytocin Administration—Active Phase Arrest

Rouse and colleagues (1999) prospectively managed 542 women at term with active-phase arrest and no other complications.

Their protocol was to achieve a sustained pattern of at least 200 Montevideo units for a minimum of 4 hours.

This time frame was extended to 6 hours if activity of 200 Montevideo units or greater could not be sustained. Almost 92 percent of these women were delivered vaginally.

These and other studies support the practice to allow an active-phase arrest of 4 hours (Rouse and associates, 2001).

MONTEVIDEO UNITS :

No of contractions / 10 MIN X Avg, intensity of contractions in mm of hg Eg : 3 X 60mmHg = 180

Uterine activity – Spontaneous labour - 200 MVUsInduction of labour - 250 – 275 MVUs

How do we calculate uterine activity ?

RCOG Guidelines : (16) Oxytocin should not be started for 6 hours following

administration of vaginal prostaglandins In women with intact membranes , if feasible amniotomy

should be performed prior to commencement of oxytocin infusion

Minimum possible dose of oxytocin should be used and titrated against uterine contractions. Maximum licensed dose is 20 mU/min and should not be exceed 32 mU/min

Local protocols should specify the dose , dilution of oxytocin and preferably be delivered via infusion pump or syringe driver with non-return valve

Infusion pumps is an electronic apparatus designed to deliver drugs and 'biologicals', at low doses.

The delivery process of these pumps are associated with local hemolysis which consists the potential benefits of a calibrated delivery system.

Infusion pumps are easy to use as these are designed keeping in mind the requirements of patrons at our vendors' end.

1. Oxytocin for the purpose of induction or augmentation of labor, will be ordered by the physician and administered by an RN. 2. Oxytocin administered for induction or augmentation of labor will be performed only in L&D after a minimum 30 minute baseline FHR and UA tracing is obtained. 3. A registered nurse is responsible for the operation of the pump (adjustments to infusion rate per MD order).4. Continuation of an oxytocin infusion beyond 20 milliunits/min requires an MD order.5. In accordance with ACOG recommendations, the practice of elective* delivery prior to 39 weeks gestation is prohibited (unless approved by Chairman/Clinical Chief). *An elective delivery is a delivery prior to 39 weeks gestation without a valid medical or obstetrical indication

Oxytocin Administration via the Infusion Pump

CONTRA-INDICATIONS

©Unfavorable fetal positions ©Uterine tachysystole ©Hypersensitivity to the drug ©Cases where vaginal delivery is

contraindicated, such as complete placenta previa, vasa previa, and cord prolapse

EQUIPMENT:

Infusion pump Premixed 500ml bag of D5% with 20 units of oxytocin Infusion pump tubing

MISCELLANEOUS:a) Castor Oil (28 ) : It is an extract from “Ricinus communis” and is mainly crude ricinoleic acid. It is known to stimulate gut peristalsis and labor most likely is stimulated due to release of prostaglandins. The method is no longer used now. One study has reported an increased incidence of meconium staining of amniotic fluid. b) Acupuncture and TENS (Transcutaneous electric nerve stimulation): Few studies ( 29-31) have reported successful induction of labor with these methods but further trials are needed before planning a large scale use.

a) Previous C. S. : » One or more previous C. S. are not a contraindication to the

induction of labor.» Cervical ripening can be done in these situations with

PGE2 gel – either intravaginal or intracervical » Misoprostol is an absolute contraindication » Oxytocin can be safely used in low doses with close

monitoring of uterine contractions and FHR.» It is preferable to have continuous electronic fetal

monitoring.

CERVICAL RIPENING AND IOL IN SPECIAL CIRCUMSTANCES

b) Twin pregnancy:› PGE 2 gel can be safely used for cervical ripening› ARM facilitates induction› Oxytocin in low doses can be used

c) Premature rupture of membranes (PROM) :› Use of PGE2 gel– 2 doses 6 hours apart is not associated

with higher incidence of infection› Misoprostol can also be used in 25 mcg dose› Oxytocin infusion should be closely monitored › Beware of hyperstimulation

d) Intrauterine fetal demise (IUFD ) :

Oxytocin is effective for IOL near term with a favorable cervix.

All prostaglandins can safely be used in recommended dosages for cervical ripening remote from term.

It is defined when Cx failed to dilate up to 3-4 cm in 24 hrs of induction.What to do now ? - Option to wait-- if No PROM and postponement is not harmful for fetus as well as mother. - Review the case and if there is urgency, Caesarean delivery is performed.

Failure of Induction

MONITORING UTERINE CONTRACTIONS Intra uterine pressures FETAL MONITORING Fetal pulse oximetry Fetal electrocardiogram wave form analysis Intermittent measurement of lactate by FBS As an adjuvant to EFM as it has high False positive rates

What's new in monitoring of labour ?

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