preterm labor (warda)
TRANSCRIPT
PRETERM LABOR
Osama M Warda MDAssistant professor of Obstetrics & Gynecology-Mansoura University- EGYPT
DEFINITION………………(WHO)
Preterm labor is the presence of
contractions of sufficient
strength and frequency to effect
progressive effacement and
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progressive effacement and
dilation of the cervix between 20
and 37 weeks' gestation
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INCIDENCE
� Total incidence = 6-10%of all pregnancies
� Spontaneous = 40-50% (of total PL)
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� PROM= 25-40%
� Obstetrically indicated = 20-25%
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COMPLICATIONS OF PRETERM BIRTH
Most of mortality and morbidity are experienced by
babies born before34 weeks gestation
Major neonatal risks include:1- Death
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1- Death 2- Respiratory distress syndrome 3- Hypothermia 4- Hypoglycaemia5- Necrotising enterocolitis6- Jaundice 7- Infection 8- Retinopathy of prematurity
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RISK FACTORS FOR PRETERM LABOR
While the exact cause of preterm labor is often
unknown, there is strong evidence that
intrauterine infection may play a role in
very early preterm labor.
Bacterial vaginosis increased the risk of
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Bacterial vaginosis increased the risk of
preterm delivery >2-fold .
Risks were higher for those screened (at
<16 weeks) than those (at <20 weeks of
gestation ). 5
RISK FACTORS FOR PRETERM LABOR,
Other risk factors include:
1. Multiple pregnancy: risk >50%
2. Previous preterm delivery: risk 20- 40%
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3. Cigarette smoking: risk 20-30%
4. Cervical incompetence
5. Uterine abnormalities
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RISK FACTORS FOR PRETERM LABOR, CONT.,
Other risk factors include:( cont.,)
6. Young age of mother - less than 16 years
7. Lower socioeconomic status.
8. Reduced body mass index (BMI<19kg/m2)
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8. Reduced body mass index (BMI<19kg/m2)
9. Antiphosphlipid syndrome.
10. Obstetric complications, including PIH,
APHge, infection, polyhydramnios, foetal
abnormalities.
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PREDICTION OF PRETERM LABOR
1. Assessment of risk factors
2. Vaginal examination to assess the
cervical status
3. Ultrasound visualization of
cervical length and dilatation
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cervical length and dilatation
4. Detection of fetal fibronectin in
cervico-vaginal secretions
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PREDICTION OF PRETERM LABOR; (CONT.)
� VAGINAL
EXAMINATION
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Digital examination is the traditional
method used to detect cervical
maturation, but quantifying
these changes is often difficult.9
PREDICTION OF PRETERM LABOR; (CONT.)
ENDOVAGINAL ULTRASOUND EVALUATION OF THE CERVIX
Vaginal ultrasonography allows a more objective
approach to examination of the cervix. “ 12-16wk”
normal cx canal length ≥ 35mm
Cervical Length RR of PTD
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<35mm 2.35
<30mm 3.79
<26mm 6.19
<22mm 9.49
<13mm 13.9910
PREDICTION OF PRETERM LABOR; (CONT.)� FETAL FIBRONECTIN TEST
(detected in cervico-vaginal secretions)
-ve FFN� Negative predictive value of 99% (good –ve)
+ve FFN
OutcomeTrophoblastGlue:
Promotes cellular Promotes cellular Promotes cellular Promotes cellular adhesion at adhesion at adhesion at adhesion at uterineuterineuterineuterine----placental placental placental placental and and and and decidualdecidualdecidualdecidual----fetal fetal fetal fetal
+ve FFN� Positive predictive value of 13-30%
Why good negative test?
99.5% of symptomatic women with
negative FFN are undelivered at 7 days
99.2% of symptomatic women with
negative FFN are undelivered at 14 days
and and and and decidualdecidualdecidualdecidual----fetal fetal fetal fetal membrane membrane membrane membrane interfacesinterfacesinterfacesinterfaces
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PREVENTION OF
PRETERM
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PRETERM
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PREVENTION OF PRETERM LABOR
Women at increased risk of
preterm delivery may be
identified by various risk
factors in the obstetric history
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factors in the obstetric history
and treated.
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PREVENTION OF PRETERM LABOR
� Supplemental progesterone� 17OHP – start 2nd trimester, continue until 36 weeks if
prior delivery before 34 wks (17OHP use in high risk women reduced PTB by 15-70%)
� QUIT SMOKING
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� Just say NO! (especially to cocaine)
� Cervical cerclage (for cvx insufficiency)
� Diagnose & treat infection� Asymptomatic bacteriuria, BV, GC, chlamydia
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DIAGNOSIS OF
PRETERM
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PRETERM
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DIAGNOSIS OF PRETERM LABOR
3 criteria to document PTL(20-37w):
1-Regular uterine contractions occur
at 4/20 min. or 8/60 min. Plus:
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progressive change in the cervix.
2- Cervical dilatation > 1 cm
3- Cervical Effacement ±80%.
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DIAGNOSIS OF PRETERM LABOR; CONT;
Suspected preterm labor with no cervical changes :
Negative FFN { + } Cervical length > 30 mm
The likelihood of delivering in the next week is less than The likelihood of delivering in the next week is less than 11%.%.
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The likelihood of delivering in the next week is less than The likelihood of delivering in the next week is less than 11%.%.
Thus most women with a negative test can safely be
sent home without treatment.
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TREATMENT
OF
PRETERM
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PRETERM
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TREATMENT OF PTB
�Tocolysis – inhibit myometrial contractility� Magnesium
� Terbutaline
� Indomethacine
� Nifedipine
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� Nifedipine
�Contraindications to tocolysis:� IUFD, lethal fetal anomalies, NRFHT
� Severe IUGR, chorio, hemorrhage
� Severe pre-e/eclampsia
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TOCOLYSIS
MgSO4 Terbutaline Indocin Nifedipine
Class Β-agonist Cox inhibitors CCB
Action Competes for Ca
↑ cAMP
↓ intracellular
Ca
↓ PGD
productionBlock Ca
influx
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Ca
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
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!RULELUCOCORTICOIDSG
�Why?� Reduce the risk of neonatal RDS, IVH, NEC,
and mortality by 50% (FIFTY!)
� Benefit observed 18 hours after 1st dose, max benefit @ 48 hours
� Give 24-34 wks (?24-32wks if PPROM)
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� Give 24-34 wks (?24-32wks if PPROM)
�How?� Enhance maturation of lung architecture
� Induce lung enzymes resulting in biochemical maturation
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CERVICAL CERCLAGE
�For cervical insufficiency which
complicates 0.1-2% of all pregnancies and
is responsible for 20% of late 2nd trimester
losses
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�Prophylactic cerclage – 12-14wks
�Rescue cerclage – when cvx changes
already detected22
CERVICAL CERCLAGE
• Shirodkar
•MacDonald’s
• Caspi’s
•Abdominal
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•Abdominal
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