Download - 4382448 preterm labour and pporm
Preterm Labour and
PPORMDr. Yasir KatibMBBS, FRCSCPerinatologest
Outline
• Definition• Burden of Illness• Etiology & Risk Factors• Diagnosis• Management
– ?tocolytics– ?antibiotics– steroids
Preterm Labour: Definition
• Regular uterine contractions + progressive cervical dilatation and/or effacement at < 37 weeks GA
Burden of Illness: Incidence
• Preterm delivery occurs in 12% pregnancies
• 3-4% were <34 weeks
• Those > 34 weeks born in tertiary care centres have survival rates = term
• Long-term sequelae mainly in those born < 34 weeks
• 70-80% occur spontaneously
Burden of Illness: Significance
• Preterm birth accounts for 75% of Perinatal mortality
• Long-term sequelae include:– CNS & neurodeveopmental problems– respiratory– blindness and deafness
• Significant physical psychological and financial burdens
Survival in Extreme Preterm Delivery
0%
21%
30%
58%63%
86%91%
0%
16%
43%
55%
63%
77%
87%
22 23 24 25 26 27 28
Gestational Age at Birth (weeks)
0%
20%
40%
60%
80%
100%
% S
urvi
val
MUMC 83 - 88 n=464 BCWCH 83 - 89 n=1024
Long-term Morbidity of Extreme PTD
44%
31%27%
22%
11% 9%
23 24 25 26 27 28
Gestational Age at Birth (weeks)
0%
10%
20%
30%
40%
50%MUMC < 29 weeks GA 1983 - 1988 n = 464
Etiology & Risk Factors
• Idiopathic• PPROM• Antepartum hemorrhage• Chorioamnionitis• Multiple pregnancy/polyhydramnios• Incompetent cervix/uterine anomaly• Maternal disease• Fetal Anomaly
Prevention
• No benefit has been demonstrated by attempts to prevent PTL with:– social interventions– bed rest– methods of cervical assessment– medications including betamimetics, magnesium, calcium
• May be some increase in gestation with:– fish oil– progesterone injections– (need further study of both to show benefit)
Diagnosis
• Establish Due Date– Naegele’s Rule– U/S
• 7-12 weeks: +/- 5d
• 13-21 weeks: +/- 1wk
• 22-30 weeks: +/- 2wk
• 30+ weeks: +/- 3wk
• (document clearly on assessments!)
Diagnosis
• History of contractions / risk factors
• Abdo exam for contractions
• Cervical exam – serial if necessary
• 20-50% preterm labour diagnosis is incorrect
• Vaginal fibronectin
• Cervical U/S
Management
• Four Objectives:– 1. Early diagnosis– 2. ID and treat cause if possible– 3. Attempt to arrest Labour when appropriate– 4. Minimize neonatal morbidity and mortality
Management
• Medications
1.MgSO4
2.Ca channel blockers
3.Cyclo-oxygenase inhibitors
4.Oxytocin receptors antagonists
5.Nitric oxcide
Arresting Labour
• Note: <40% patients in preterm labour are candidates for tocolysis
• Goal of tocolysis:– get 48 hrs for steroids to have effect– transport
Tocolysis
• When NOT to tocolyse:– significant vaginal bleeding– suspected fetal asphyxia– intraamniotic infection– IUFD or lethal anomaly– maternal indication– imminent delivery
Tocolysis: Options
• ECPC:– no effect:
• fluid bolus
• ethanol
• sedation
• magnesium sulphate
Tocolysis
• ECPC:– Some effect:
• betamimetics
• calcium channel blockers
• indomethacin
• antimicrobials
• oxytocin antagonists
Antimicrobials: ORACLE II
• Kenyon et al. Lancet 2001 Mar 31;357(9261):989-94– Methods:
• multicentre randomised controlled trial• 6295 women in preterm labour (diagnosis left to individual
clinician) w/ IM, no evid infection & “substantial uncertainty as to whether antbiotics should be prescribed”
• randomized to:– erythromycin– co-amoxiclav– both– placebo
ORACLE II
• Conclusion:– Abx should not be routinely prescribed in PTL
w/o evidence of infection or PPROM
Effect of Corticosteroids on Neonatal Effect of Corticosteroids on Neonatal OutcomesOutcomes
RDS
IVH
NEC
Perinatal Infection
Neonatal Death
0.1 1 10Odds Ratio (95% Confidence Interval)
Crowley CCPC Review No. 02955
Recommendations: NIH
• NIH Consensus Statement JAMA Feb. 1, 1995 273:5:411-417.– fetuses 24-34 weeks w/ threatened PTL candidates for
corticosteroids– pts eligible for toco should be eligible for steroids– Tx: betamethasone 12mg IM Q 24hr x 2
• Dexamethasone 6 mg IM Q 12 hr x 4
– Max benefit 24 hr – 7d, but..– Give even if delivery anticipated w/in 24 hrs b/c some
still beneficial
Upper Gestational Limit
• NIH 1995: give steroids to 24-34wks (adopted by SOGC 1995)
• ALARM: 34-36 wks
• UK Royal College of Obs and Gyn: up until 36 wks
20 24 28 32 36 40
Gestational age (weeks)
0
20
40
60
80
100
RD
S (
%)
RDS - Incidence
RDS: NNT
GA (wks) NNT 95% CI
< 31 4 2, 17
31-34 15 10, 31
> 34 145 25, infinite
GBS PROPHYLAXIS
• The benefits of group B streptococcal (GBS) prophylaxis are well established.
• Intrapartum prophylaxis should be initiated in any patient with an unknown GBS status or a history of a positive culture during the present pregnancy.
• Treatment is not indicated if there was a recent negative anovaginal culture
Universal GBS culture at 35-37wks gestation
GBS prophylactic intrapartum antibiotics
Antibiotics recommended
Not recommended
Prior newborn with GBS disease
Prior documented GBS bacteriuria
GBS positive culture during pregnancyGBS unknown:
PTL < 37weeks
ROM > 18hours
Intrapartum fever > 38oC
Previous pregnancy with positive GBS screening culture
Planned C/S in absence of labor or ROM
Negative GBS screening culture in late gestation regardless of intrapartum risk factors
CDC RECOMMENDATIONS
The effect of antibiotics on GBS
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
< 1hr 1 - 2hr 2 - 4hrs > 4hrs
Time
Red
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n G
BS
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Take home points
• Accurate diagnosis key– Dating– Really labour?
• Tocolysis (where appropriate)– choices
• Ca channel blocker
– goals:• give corticosteroids (once)• transfer to appropriate level facility
• To reduce neonatal mortality & morbidity:– Steroids
THANK YOU