4. INTRODUCTION
• Preterm labor is one of the leading cause of perinatal
morbidity and mortality.
• Preterm delivery effects almost 23% pregnancies in
developing countries like India
5. DEFINITIONS
Pre term labour is defined as onset of
labour prior to the completion of 37 weeks (259
days) of gestation and after the attainment of
period of viability. (22 weeks & 500 gms by WHO)
6. INCIDENCE
Incidence varies from 5-15%
• Cause unidentified in up to 50% of PTB
• Majority of women with risk factors will not have PTB
• Many women who have a PTB have no risk factors
• 8.7% of singleton births
• 66% of multiple births
Frequency of preterm birth by gestational age
• < 28 weeks : 0.82 %
• < 32 weeks: 2.2 %
• 33-36 weeks: 8.9 %
• < 37 weeks: 11.2
9. RISK FACTORS FOR PTB
Clinical Factors in preterm Labor
Maternal
Low socio economic
status
Age <18 years or >40
years
Low pregnancy weight
Smoking
Substance abuse
Multiparity
Past Obstetric History
Previous history of
preterm delivery
Previous history of
second trimester
abortion
Uterine Factors
Uterine volume
increased:
Polyhydramnios,
Multifetal gestation
Uterine anomalies
Incompetent cervix
Trauma
Infection
10. RISK SCREENING
History
• Comprehensive history review including maternal characteristics and
previous medical/pregnancy history
Counselling
• Psychosocial needs, smoking, lifestyle, chronic disease
• Involve a multidisciplinary team and refer when needed/appropriate
Bacterial
vaginosis
• Offer screening and treatment to women with symptoms of BV
and/or history of PTB
Bacteri
-uria
• Offer routine ward test urine screening and treatment to women
Transvaginal
cervical
length
• If history of PTB: recommend serial TVCL screening from 14–24
weeks
• If low risk of PTB: consider a single TVCL measurement during mid-
trimester USS
11. MECHANISM OF PRETERM LABOR
CAUSES MECHANISM
• Stress
• Premature activation
of physiological
effectors
Activation of maternal-fetal HPA-axis
• CRH → Fetal adrenal androgens
• Placental estrogen and progesterone
• Inflammation and
infection
• Pro-inflammatory cytokines
• Fetal inflammatory response syndrome
• Ischemia or
hemorrhage
• Thrombin activation
• Pathological Uterine
distension
• Increased gap junction along with contraction
associated protiens and upregulation of prostaglandins
and oxytocin receptors
12. painful or painless uterine
contractions
SYMPTOMS
Lower abdominal pain or
menstrual like cramping
Pain in lower back
Blood stained vaginal
discharge
Sensation of pelvic or
vaginal pressure
13. SIGNS
• Palpable uterine contractions
• Engagement of presenting part
• Cervical effacement & dilatation
• Show (may be blood stained)
• Bulging membranes
• Rupture of membranes
15. DIAGNOSTIC TEST contd...
Pelvic exam
• Dilatation(≥2cm) & Effacement (80%)of the cervix
• Length of cervix ≤2.5cm
• Funnelling of internal OS
• Pelvic pressure, backache or vaginal
discharge or bleeding.
Uterine monitoring
• Regular uterine contractions with or without pain (at
least one in every 10 mins.)
16. Lab tests
• Full blood count
• Routine urine -analysis,culture &
senstivity
• Cervicovaginal Swab- culture,fibronectin
• Serum electrolytes & glucose levels- when tocolytic
agents are to be used
DIAGNOSTIC TEST contd...
17. TRANSVAGINAL CERVICAL LENGTH (TVCL)
• Risk of PTL increases with a shorter cervical length
• If history of PTL: recommend serial TVCL screening from
14–24 weeks
• If low risk of PTL: consider a single TVCL measurement
during mid-trimester USS
• Consider therapeutic interventions when TVCL is < 25 mm
DIAGNOSTIC TEST contd...
18. FETAL FIBRONECTIN TESTING
Sample : from the posterior fornix of the vagina
Indications:
• Symptomatic preterm labour 24 - 36 weeks
• Intact membranes and Cervical dilatation less than 3 cm
Contraindications:
• Ruptured membranes
• Vaginal bleeding & Cervical cerclage in situ
Relative Contraindications:
• After the use of lubricants or disinfectants
• Within 24 hours of coitus or vaginal examination
DIAGNOSTIC TEST contd...
19. Fibronectin
• A protein that binds the fetal membranes to decidua.
• Normally found in cervicovaginal discharge before 22 wks
& again after 37wks of pregnancy presence of fibronectin
in cervicovaginal discharge b/w 24 wks & 34 wks
• Predicts pre-term labour
DIAGNOSTIC TEST contd...
21. PREVENTION
• Seek regular prenatal care & Consider pregnancy spacing
• Eat a healthy diet & Avoid risky substances
• Be cautious when using assisted reproductive technology
• Taking preventive medications , who has short cervix
(Progesterone)
• Restricting sexual activity & Limiting certain physical
activities.
• Manage chronic conditions such as DM, Increased BP.
22. PREVENTION contd...
Primary Care:
• To reduce the incidence of preterm labour by reducing
the high risk factors(e.g. infection etc.)
Secondary Care:
• Includes screening tests for early detection
& prophylactic treatment (e.g. tocolytics)
Tertiary care:
• To reduce the perinatal morbidity & mortality after the
diagnosis (e.g. use of corticosteroids)
23. CERVICAL CERCLAGE
• Consider cervical cerclage for women with a history
of:
– One or more prior spontaneous PTL and/or second-
trimester loss related to painless/painful cervical
dilation and in the absence of labour or placental
abruption or
– Prior cerclage due to painless cervical dilation in
second trimester or Cervical incompetence
24. • Cerclage may be indicated if TVCL is less than 25 mm
before 24 weeks if:
– Preterm prelabour rupture of membranes (PPROM) in
a previous pregnancy
– A history of cervical trauma/surgery
– Prior spontaneous PTB before 34 weeks gestation and
Current pregnancy singleton
CERVICAL CERCLAGE
25. PROGESTERONE THERAPY
Reduces risk of PTL in women with a history of spontaneous
PTL and/or short cervix, Consider for:
• Singleton pregnancy from 16–24 weeks with a history of
prior spontaneous PTB
• Asymptomatic women with incidentally diagnosed short
cervix in the second trimester
• Not recommended for use in multiple pregnancies
26. MANAGEMENT OF PRETERM LABOR
• Bed rest and hospitalization.
• In utero transfer
• Sedation
• Hydration
• Corticosteroids to induce fetal lung maturation
• Treatment of infection with antibiotics
• Inhibition of uterine contractions with tocolysis
27. DEFINITIVE
Corticosteroid Administration
– Single dose antenatal corticosteroids to women between
24-34 weeks with High risk of preterm birth
– Ante-natal corticosteroid should be given to all women
whom an elective caesarean section planned prior to
38weeks. (level 2)
28. • Tocolytic therapy may offer some short-term benefit in
the management of preterm labor.
Aim of tocolysis :
Suppress uterine contractions and delay preterm delivery
to allow in-utero transfer to an appropriate level facility .
2-allow for the administration of corticosteroids and MAG
SULF for neuroprotection
TOCOLYSIS :
29. Indications of Tocolytics
Acute Preterm Labor
Completing a course
of corticosteroids or
in utero transfer
Reduce the
proportion of births
occurring within 7
days
Maintenance -
Acute
Preterm labor
Both oral and
parenteral may be
for maintenance
therapy beyond
48–72 hours
Prophylaxis of
Preterm Labor
in women who are
at
high risk for
Preterm labor
30. Contraindications :
• Gestation > 34 weeks & Labour is too advanced
• In utero fetal death & Lethal fetal anomalies
• Suspected fetal compromise & Placental abruption
• Suspected intra-uterine infection
• Maternal hypotension: BP < 90 mmHg systolic
Relative contraindications :
• Pre-eclampsia & Multiple pregnancy
• Placenta praevia & Rupture of membrane
TOCOLYSIS :
32. REGIMENS FOR TOCOLYSIS
1. Calcium channel blockers
• 1st line tocolytic agent in developing countries
• Nifedipine 20 mg oral followed by 10 mg, 4-6 hourly
until uterine contractions cease followed by 10 mg 8
hourly for about a week
2. Ritodrine hydrochloride
• IV therapy (100 mg in 500 ml 5% Dextrose). Starting
with 0.05 mg/mt (5 drops/mt) to a maximum of 0.30
mgmt (30 drops/mt) and continued for 48 hours.
• Currently ritodrine is not much preferred due to risk
of complications like pulmonary edema, hypotension
etc
33. REGIMENS FOR TOCOLYSIS
3. Isoxsuprine
• IV therapy at rate of 60 microgram (8 drops/mt) in
500 ml 5% dextrose.
• Isoxsuprine 10 mg IM every 4-6 hours initially
followed by maintenance dose of 60-80 mg daily
(orally or IM). Side effects same as Ritodrine.
4. Terbutaline
• IV therapy bolus of 250 microgram followed by 10-50
microgram/mt until labour stops.
•Maintenance of 2.5-5 mg orally may be given 4-6
times a day
• Side effects same as Ritodrine.
34. REGIMENS FOR TOCOLYSIS
5. Magnesium sulphate
• Safe drug with limited tocolytic efficacy
• Loading dose of 4-6 g over 20-30 mts followed by
infusion of 1-2 g/hr.
•Evidence suggests that if used between 24 and 32 weeks,
for atleast 12 hours, it has tocolytic and neuroprotective
role by decreasing incidence of cerebral palsy.
4. Indomethacin
• Indomethacin in dose of 50 mg loading dose orally
followed by 25-50 mg 6 hourly is effective.
• Some studies reported side effects of fetal abnormalities
like patent ductus arteriosus, necrotizing enterocolitis and
even death whereas other studies have not reported any
side effects.
35. MANAGEMENT-FIRST STAGE
• Patient is put to bed to prevent PROM
• To ensure adequate fetal oxygenation
• Strong sedative avoided
• Epidural analgesia is of choice
• Labour should be watched by intensive clinical
monitoring
• In case of delay, caesarean section should be performed
36. MANAGEMENT-SECOND STAGE
• The birth should be gentle &slow to avoid rapid
compression & decompression of head
• Episiotomy may be done under local anesthesia to
minimize head compression if there is perineal resistance
• The cord is to be clamped immediately at birth to prevent
Hypervolemia & Hyperbilirubinemia
• To shift the baby to intensive neonatal care unit under
care of neonatologist
37. PROGNOSIS
Results in high Perinatal mortality & Perinatal morbidity
• With intensive neonatal care unit, survival rate of the
baby weighing b/w 1000 to 1500 gm is more than 90%
• With use of surfactant, survival rate of infants born at
26wks is about 80%
38. REFERENCES
• D.C.Dutta,”Textbook of Obstetrics including
Perinatology and Contraception". Seventh Edition.
• J.B. Sharma, “Midwifery & Gynaecological Nursing”
Avichal Publishing company:1st edition
• Jacob, Annamma (2009). A Comprehensive Textbook of
Midwifery.Second Edition. New Delhi: Jaypee Brothers
Medical Publishers.
