Department of Obst. & GynaeG.R. MEDICAL COLLEGE, GWALIOR

SEMINAR PRESENTATION

MANAGEMENT OF PRETERM LABOUR

Chairperson Prof. Dr. (Mrs.) V. AgrawalProf. & HOD of Obst. & GynaeG.R. Medical College Gwalior

GuideProf . & Dr J BindalDepartment of Obst. & GynaeG.R. Medical College Gwalior

Presented by Dr. Divya Kakrani

IIIrd Year R.S.O. Obst. & Gynae

DEFINITION PREERM BIRTH-

CAUSES & OUTCOME

PREDICTION ANTECEDENT

FACTORS PREVENTION TREATMENT

MANAGEMENT OF PRETERM LABOUR

DEFINITION

Preterm labor is the presence of contractions of sufficient strength and frequency to effect progressive effacement and dilation of the cervix between 20 and 37 weeks' gestation

Contraction of four in 20 min, or 8in 60 min plus progressive change in cervix Cervical dialatation greater than 1cm Cervical effacement of 80% or greater

@Such explicit criteria do not appear in more recent guidelines (ACOG 2008)

ACOG CRITERIA to document PRETERM LABOUR

MORBIDITY IN PRETERM INFANTS

LATE PRETERM INFANTS34-36 WKS

(71.2% of all preterm births)

SMALL PRETERM INFANTS<34WKS

LONG TERM SEQUELAE PRESENT

26 WKS OR 750GM –current threshold Not appropriate to initiate resusitation in

MGA <23 wks

THRESHOLD OF VIABLITY

Induced labour or prelabour caesarian- for maternal and foetal indications

Spontaneous unexplained preterm labour with intact membranes

Idiopathic preterm premature rupture of membranes(PROM)

Twins and high order births Drugs like cocaine or methamphetamine Uterine and cervical causes-fibroid uterus,

abnormal shape of uterus,thin cervix

CAUSES OF PRETERM DELIVERY

Causes for preterm birth

Large for gestational age Preeclampsia Fetal distress IUGR Placental abruption Others-chronic hypertension, placenta

previa, unexplained bleeding, diabetes, renal disease, Rh incompatiblity and congenital malformations

MEDICAL AND OBSTRETIC INDICATIONS

PROGESTERONE WITHDRAWL-reversal of estrogen progesterone ratio. Serum progesterone conc do not fall

OXYTOCIN INITIATION- serum conc doesn’t change, so unlikely cause

INFLAMMATORY DECIDUAL REACTION

SPONTANEOUS PRETERM LABOUR

INFECTION- Microbes involved are-

-ureaplasma urealyticum -mycoplasma hominis -nisseria gonorrhoea -group B streptococci -trichomonas vaginalis

Rupture of membranes prior to 37 wks

PROM AND PPROM

Can preterm labor be predicted?

Prediction of preterm labor

1. Risk markers2. Home uterine activity monitoring

(HUAM)3. Salivary estriol

4. Screening for bacterial vaginosis (BV)5. Screening for fetal fibronectin (fFN)6. Cervical ultrasonography (cervical

length assessment

A previous history of preterm labor is the strongest risk marker

Risk markers

Other risk markers include multiple pregnancy Cigarette smoking, cervical incompetence or

uterine anomalies, uterine over-distension (polyhydraminos,

macrosomia, fibroids), previous cervical surgery , using smokeless

tobacco , bleeding in early pregnancy , bacterial

vaginosis, poor socioeconomic or educational status, and young or advanced

maternal age. Antiphospholipid syndrome

Risk markers

HUAM is based on the principle of tocodynamometry

Telemetric recording of uterine contractions and transmission to a monitoring center and daily feed back from healthcare practitioner

Not useful so not recommended in routine practice (ACOG 1995)

Home uterine activity monitoring (HUAM)

Premature activation of HPA axis in preterm labor may increase the serum and salivary levels of estriol in the mother.

Very poor sensitivity and specificity and has a very high false positive rate

Diurnal variation of the maternal salivary estriol level

Administration of betamethasone to effect surfactant production may suppress maternal salivary estriol levels

Salivary estriol

- Normal hydrogen peroxide producing , lactobacilli predominant vaginal flora is replaced by anaerobes –Gardenella vaginalis , mobiluncus sp , mycoplasma hominis.

- Chronic stress n frequent douching predispose

- antibiotics not helpful in preventing PTL

#NUGENT SCORE- relative concentrations of above mentioned phenotypes are studied in a gram stained smear

BACTERIAL VAGINOSIS

Fishy odour when mixed with 10% KOH AMINE TEST / WHIP TEST. pH of vaginal discharge more than 4.5 Presence of clue cells on smear. Treatment does not alter preterm birth Screening routinely not recommended

(ACOG 2001)

Screening for bacterial vaginosis (BV)

Basement membrane protein produced by the hepatocytes , fibroblasts , endothelial cells , fetal amnion and functions as an ‘adhesion binder’.

attachment of the placenta and membranes to the uterine decidua

Present in maternal blood and amniotic fluid Normally detectable in cervical secretions until

16-20 weeks of gestation. After 24 weeks (>50 ng/ml ) of gestation may

indicate disruption of the normal adhesion between chorioamnion and the underlying decidua.

Screening for fetal fibronectin (fFN)

Mean cervical length at 24 wks is approx 35mm

Women with progressively shorter cervix predisposed to PTL.

Funneling of cervix if present increases risk

CERVICAL CHANGES

THREATENED ABORTIONS LIFESTYLE FACTORS-smoking , inadequate

maternal wt gain , illicit drug usage WORK DURING PREGNANCY- only long and hard

physical labour are associated GENETIC FACTORS PERIODONTAL DISEASE-chronic anaerobic

inflammation of gums, BIRTH DEFECTS INTERVAL BETWEEN PREGNANCIES- smaller intervals

more associated PRIOR PRETERM BIRTHS

ANTECEDANTS AND CONTRIBUTING FACTORS

PROGESTERONE Weekly im injections reduce PTL. Daily 100mg progesterone suppositories

reduce PTL in women with prior PTL or circlage or uterine malformation.

Vaginal progesterone gel not useful in women with prior PTL

Efficacy in nulliparous with short cervix is under way.

PREVENTION OF PRETERM BIRTH

Prophylactic use of 17 hydroxy progesterone caproate to prevent preterm labor revealed a significant decrease in preterm birth .

However, it has not successfully inhibited active preterm labor.

17 Hydroxy -Progesterone Caproate

PRECONCEPTIONAL n DURING PREGNANCY-decreasing work hours’standing <6hr per day

Vitamin supplementation-calcium supp decreases PTL

Smoking cessation Self monitoring of vaginal pH and yoghurt

treatment

PREVENTION

Cervical circlage For cervical insufficiency which complicates

0.1-2% of all pregnancies and is responsible for 20% of late 2nd trimester losses

Prophylactic circlage – 12-14wks. Not much fruitful.

Rescue circlage – when cvx changes already detected

Efficacy seen in women with prior PTL

Treatment Inhibition of labor Corticosteroid Antibiotics Others.

Inhibition Of LaborBed rest :DVTHydration &sedation

Tocolytics

Hydration Intravenous hydration does not seem to be beneficial, even during the period of evaluation soon after admission,

Women with evidence of dehydration may, however, benefit from the intervention.

Is Tocolysis Better Than No Tocolysis For Preterm Labour?

It is reasonable not to use tocolytic drugs, as there is no clear evidence that they improve outcome. However, tocolysis should be considered if the few days gained would be put to good use, such as completing a course of corticosteroids, or in utero transfer

Choice Of Tocolytic Drug

B –Sympathomimetic (Ritodrine)Magnesium sulphateIndomethacin Nifedipineatosiban

Most authorities do not recommend use of tocolytics at or after 34 weeks' .

There is no consensus on a lower gestational age limit for the use of tocolytic agents.

Choice Of Tocolytic Drug If a tocolytic drug is used, ritodrine

no longer seems the best choice.

Atosiban or nifedipine appear

preferable as they have fewer

adverse effects and seem to have

comparable effectiveness.

MgSO4 Terbutaline Indocin Nifedipine

Class Β-agonist Cox inhibitors CCB

Action Competes for Ca

↑ cAMP↓ intracellular

Ca

↓ PGD production

Block Ca influx

Side Effect Pulm edema, ? ↑ ped M&M

Tachy, ↓BP, palp, ↓K,

pulm edema

N/V, gastritis, narrowing of

DA, oligo

↓BP, reflex tachy, ? ↓ of blood flow

Efficacy Not very good!

No ↓ of PTB @ 7 days, sx

relief

Appears to be more

effective than placebo

↓ # of women giving birth at

7 days

Magnesium Sulfate

Magnesium sulphate is ineffective

at delaying birth or preventing

preterm birth, and its use is

associated with an increased

mortality for the infant.

@ Neuroprotective for foetus-decreses

chances of cerebral palsy

Nitric Oxide DonorsThere is insufficient evidence to

support the routine

administration of nitric oxide

donors (nitroglycerin )in the

treatment of preterm labor.

Side effect- Maternal

hypotension

Indomethacin Indomethacin can be used as a second-line tocolytic agent in early gestational age preterm labors.

Indomethacin Indomethacin therapy for < 48 hours < 30-32 weeks' gestation)Not > 200mg/day.appears to be a relatively safe and effective tocolytic agent

Indomethacin Indomethacin may be a first-line tocolytic in:

Associated polyhydramnios :

( to have renal effects of indomethacin)

Indomethacin Capsule 25mg oral Amp 50mg Rectal Supp 100 mg

50 mg Loading dose

Then 25-50mg /6hs

Indomethacin Fetal risk:Premature closure of the ductus.Renal and cerebral vasoconstriction.

Necrotising enterocolitis Common with high dose and prolonged exposure.

Atosiban: TractocilAtosiban, a synthetic

peptide, is a competitive

antagonist of oxytocin at uterine oxytocin

receptors.

Atosiban: TractocilAtosiban - compared with beta-

agonists- has:Little difference in the effect of these

agents on delayed delivery

Fewer maternal adverse effects than beta-

agonists, such as chest pain, palpitations

, tachycardia , hypotension ,

dyspnoea ,vomiting , and headache.

NifedipineNifedipine- compared with ritodrine -

has:

Higher delaying of delivery for >48

H.

Lower risk of RDS &Neonatal jundice.

Lower admission to NN ICU

Fewer maternal adverse effects

Nifedipine20mg initial

10-20 mg /4-6 h

Epilate capsule :10mg

Epilate retard Tablet: 20 mg

NifedipineWhen tocolysis is indicated for women

in preterm labor, calcium channel

blockers are preferable to other

tocolytic agents compared, mainly

betamimetics.

Further research should address the

effects of different dosage regimens

and formulations

General contraindications Acute fetal distress (except intrauterine

resuscitation) Chorioamnionitis Eclampsia or severe preeclampsia Fetal demise (singleton) Fetal maturity Maternal hemodynamic instability 

Contraindications to Tocolysis for Treatment of Preterm Labor

Beta-mimetic agents Maternal cardiac rhythm disturbance or other

cardiac disease Poorly controlled diabetes, thyrotoxicosis or

hypertension

Magnesium sulfate Hypocalcemia Myasthenia gravis Renal failure

Contraindications for specific tocolytic agents

Indomethacin (Indocin) Asthma Coronary artery disease Gastrointestinal bleeding (active or past history) Oligohydramnios Renal failure Suspected fetal cardiac or renal anomaly

Nifedipine (Adalat, Procardia)

Maternal liver disease

Beta-adrenergic agents Hyperglycemia Hypokalemia Hypotension Pulmonary edema Cardiac insufficiency Arrhythmias Myocardial ischemia Maternal death

Potential Complications of Tocolytic Agents

Magnesium sulfate Pulmonary edema Respiratory depressionCardiac arrestMaternal tetany Profound muscular paralysis Profound hypotension

Indomethacin (Indocin) HepatitisRenal failure Gastrointestinal bleeding

Nifedipine (Adalat, Procardia) Transient hypotension

B -Sympathomimetic Agents. Maternal: pulmonary edema, myocardial ischemia, arrhythmia, and even maternal death.

Fetal : arrhythmia, cardiac septal hypertrophy , hydrops, pulmonary edema, and cardiac failure. hypoglycemia, periventricular-intraventricular hemorrhage, and fetal and neonatal death. .

Maintenance Tocolysis Is Not Recommended For Routine Practice in threatened PTL.

CorticosteroidsThe optimal treatment-delivery

interval for administration of

antenatal corticosteroids is

after 24 hours but < 7 days

after the start of treatment.

Decreses RDS , IVH.

CorticosteroidsTwo 12 mg doses of betamethasone

given IM 24 hours apart, Or

Four 6 mg doses of dexamethasone

given IM 12 hours apart (I-A).

There is no proof of efficacy for any

other regimen.

Antibiotics There is no evidence of clear overall benefit from prophylactic antibiotics for preterm labour with intact membranes on neonatal outcomes.

Screening for GB Strep.

ACOG Advises Screening All Pregnant Women for Group B Strep.

Group B Streptococci (GBS) Prophylaxis

All patients in preterm labor are considered at high risk for neonatal GBS sepsis and should receive prophylactic antibiotics regardless of culture status.

Group B Streptococci (GBS) Prophylaxis

The goal of this strategy is to prevent neonatal sepsis, and not to prevent preterm birth.

Prophylactic Vitamin K Or Phenobarbital

Have not been shown to significantly prevent periventricular haemorrhages in preterm infants.

ConclusionsVarious strategies that have been used to prevent or treat preterm labor, haven't proven effective.

Tocolysis should be considered only for 2 days- if needed - for corticosteroids thereby , or in utero transfer to a tertiary center .

ConclusionsIf a tocolytic drug is

used, ritodrine no

longer seems the best

choice.

ConclusionsOther drugs with fewer adverse effects

and comparable effectiveness are now

recommended

Atosiban or nifedipine have been

recommended by RCOG

Indomethacin may be used as a 2nd

line tocolytic or if there is

polyhydramnous

ConclusionsMaintenance tocolytic therapy has no proven effect.

It cannot be recommended for routine practice.

PSCHYCOSOCIAL SUPPORT AND COUNCILLING FOR

NEXT PREGNANCY

CARBON MONOOXIDE HUMAN GONADOTROPIN

NEWER DEVELOPMENTS

Thank YouThank You