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Preterm Labor & Delivery

Challenges and Progress

Elmar P. Sakala, MD, MA, MPH Professor of Gynecology & Obstetrics

Loma Linda University School of Medicine

Loma Linda University Children’s Hospital 1st Annual Perinatal/Neonatal Conference

September 28, 2016

OBJECTIVES

1%Define%preterm%labor%and%its%pathophysiology%

2%Explore%trends%in%epidemiology%of%preterm%birth%

3%Review%risk%factors%for%and%predictors%of%preterm%birth%

4%Outline%diagnosis%and%treatment%preterm%labor%

5%Discuss%screening%and%prevenFon%of%preterm%birth%

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2%

Replace'Phrase''Term'Pregnancy’'with'4'Categories'ACOG/SMFM'–'November,'2013'

37%%%%%%%38%%%%%%%%39%%%%%%%40%%%%%%%%41%%%%%%%%42%%%%%%%43%

EARLY'Term%%

LATE'Term%%

POST'Term%

FULL'Term%

…………..Weeks%of%Pregnancy…………….%

hOp://www.obimages.net/cervix/%

Medical'IndicaOons'

33%'

Neo

natal%M

ortality%Rate%

GestaFonal%Age%in%Weeks%

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3%

hOp://www.prb.org/images09/PercentPrematurBirths.gif%

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4%

SAN'BERNARDINO'9.7%V%C%grade%

RIVERSIDE'8.3%V%B%grade%

Preterm%Birth%Rates%in%US%CiFes%

Riverside'

San'Bernardino'

RISK''FACTORS'''''''''''''''''''''''''''''''''

for%%Preterm%Birth%

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5%

MulOple'GestaOon''and%Preterm%Births%

93%'

57%'

10%'

ETHNICITY'and%Preterm%Births%

16%'Black'

10%'White'

MATERNAL'AGE'and%Preterm%Births%

Predictors%of%Preterm%Delivery%

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6%

hOp://clinicalgate.com/wpVcontent/uploads/2015/03/001032_f103V005V9781437707557.jpg%

PRETERM'Delivery'

UTERUS'ContracOons'

CERVIX'Effacement'DilaOon'

MEMBRANES'Rupture'

Final'Common'Pathway'''''''''''''''''''''''''''''''''%

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7%

%%%Cervical%Length%%%%%%%%%%

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8%

http://content.answers.com/main/content/img/medTest/f025001.jpg

Normal TV Sono CERVICAL'LENGTH'

40V35%mm%

Preterm Birth Risk CERVICAL'LENGTH'

<%25%mm%

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9%

CerviLenz

NO'intervenOons'if'TWINS!'''

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10%

•  Birth%<34%weeks% % %down%70%'

•  Birth%<37%weeks% % %down%45%'

•  Neonatal%death % % %down%55%'

•  Assisted%venFlaFon% %down%60%'

•  NEC%admissions % % %down%70%'

•  NICU%admission % % %down%75%'

2013%metaVanalysis%analyzed%39%randomized%trials%IVH,%neonatal%sepsis%&%ROP%reFnopathy%not%staFsFcally%significant.%

•  Birth%<28%wks%% % % %down%50%'''

•  Birth%<33%wks% % % %down%40%'''•  Birth%<35%wks% % % %down%30%'''•  RD%Syndrome% % % %down%50%'''

•  Neonatal%M&M%% % %down%43%'''•  Birth%Weight%<1500%g% %down%45%'''•  NICU%admission%% % %down%25%'''

•  Mechanical%venFlaFon%down%34%'''

5%placeboVcontrolled%randomized%trials%(n%=%775%pregnancies)%%

Contemporary%ObVGyn,%October%2002%

McDonald%Cerclage%%1957%

Shirodkar%Cerclage%1955%

17aOHaP'Weekly%IM%injecFon%

Cerclage'+'17aOHaP'

Weekly%IM%injecFon%%

Progesterone'Daily%vaginal%suppository%

YES'

YES'

NO'

NORMAL'%%

'SHORT'%%

SHORT'%%

+'

+'

+'

IntervenFons%to%prevent%Preterm%Birth%%%

IntervenOon' 'Prior'Preterm'

Cervix'Length'

+'NOTHING!!' NO'NORMAL'%%

NO'intervenOons'if'TWINS!'''

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11%

•  The clinical findings of true labor are same whether preterm or term labor. Early findings can be non-specific and can be present for many hours in women without cervical change:

• MenstrualVlike%cramping'• Mild,%irregular%contracOon'•  Low%back'ache'•  Pressure%sensaFon%in%vagina%%• Vaginal'mucus'discharge%

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12%

• Gestational Age: – 20 to 36 weeks

•  Gestational Age: –  20 to 36 weeks

• Persistent uterine contractions: – 4 in 20 minutes – 8 in 60 minutes

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13%

Classification of UTERINE CONTRACTIONS

A

B

C

D

U

?

Clinical CRITERIA to diagnose PTL •  GestaOonal'Age:'

–  20%to%36%weeks%•  Persistent'uterine'contracOons:'

–  4%in%20%minutes%

–  8%in%60%minutes%

•  Digital'cervical'exam'findings:'– Cervical'dilaOon'>2'cm'

– Cervical'effacement'>'80%'

– Change'in'effacement'or'dilaOon'

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14%

Predictor%of%Preterm%Delivery%

“Trophoblast Glue”

Amnion%&%Chorion%

Fetal%FibonecFn%(fFN)%Maternal%Decidua%

Fetal Fibronectin (fFN)

•  Sensitivity & Specificity (5%randomized%trials)%– Delivery%within%7V10%days%of%tesFng:%77%%&%83%%– Delivery%<%34%weeks%gestaFon:%69%%&%84%%– Delivery%<%37%weeks%gestaFon:%61%%&%82%%

•  Positive'predicOve'value'a'26% •  Negative'predicOve'value'a'2.4% •  Negative is more helpful than a Positive

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15%

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16%

ContraindicaFons%to%tocolysis%

Severe%abrupFon%Ruptured%membranes%ChorioamnioniFs%

Lethal%anomaly%Fetal%demise%Fetal%jeopardy%

Eclampsia%Severe%preeclampsia%Advanced%dilaFon%

CondiFons%under%which%stopping%labor%%%%%%%%%%%%%%%%%%%%%%%%%%%%is%either%dangerous%to%Mom/baby%or%fuFle.%

At'what'point'is'stopping'labor'not'cost'

effecOve?'

Cost'per'case'

GestaOonal'Age'in'weeks'

Speculum exam with wet non-lubricated speculum

•  Estimate cervical dilation: >%3%cm%supports%diagnosis%of%PTL%

•  Assess any bleeding: abrupFo%vs%placenta%previa%

•  Evaluate for PROM: pooling,%nitrazine,%fern%tesFng%

•  Obtain fFN specimen: rotate%swab%10%sec%in%posterior%vaginal%fornix%

Laboratory Evaluation

•  Group B strep culture:'(rectovaginal)%if%not%done%within%the%previous%five%weeks.%%AnFbioFcs%may%be%started%if%needed.%

•  Urine culture: looking%for%asymptomaFc%bacteriuria%

•  Urine drug screen: in%paFents%with%substance%abuse%risk%factors%

•  Fetal fibronectin: (fFN)%vaginal%swab%

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17%

GestaFon%WEEKS:''–  >%34;%<34'

Cervical%DILATION:''–  >%3%cm;%<%3%cm%

TV%CERVICAL LENTH:''–  >30%mm,%20V30%mm,%<20%mm'

Fetal%FIBRONECTIN:''–  posiFve,%negaFve'

1'

2'

3'

4'

•  Perinatal M&M too low to%jusFfy%potenFal%maternal/fetal%complicaFons%&%costs%

•  Short term prolongation of%pregnancy%does%NOT%significantly%improve%outcome%

•  No benefit to steroids or tocolysis – Observe'for'4a6'hours'to%assess%progressive%cervical%dilaFon%and/or%effacement%

–  If'no'cervical'change'discharge%home%

•  Perinatal M&M are high enough to%jusFfy%potenFal%maternal%&%fetal%complicaFons/costs%

•  Short term prolongation of%pregnancy%may%significantly%improve'outcome'– DIAGNOSIS'of%Preterm%Labor%is%CONFIRMED'

– No'benefit'to%assess%TV%cervical%length%or%fFN%%– Admit%and%iniFate%preterm%labor'intervenOons'– Transfer%to%higher%level%care%(if%needed)%

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18%

Cervical'length'''>'30'mm:%%– LOW%risk%of%delivery%within%7%days%(<%5%)%regardless%of%fFN%results%

– DIAGNOSIS'of%Preterm%Labor%is%RULED'OUT'

– No'fFN'specimen%to%lab%– Observe%4V6%hours%

•  NO%cervical%change%–%PTL%ruled%out%–%DISCHARGE'•  IF%cervical%change%–%%PTL%confirmed%–%ADMIT'

Cervical'length''''<'20'mm:%%– HIGH%risk%of%delivery%within%7%days%(>%25%)%regardless%of%fFN%results%

– DIAGNOSIS'of%Preterm%Labor%is%CONFIRMED'

– Discard'fFN'specimen%– ADMIT%and%iniFate%preterm%labor%treatment%– TRANSFER%to%higher%level%care%(if%needed)%

Cervical'length''''20a30'mm:%%– MODERATE%risk%of%delivery%within%7%days%but%most%will%not%deliver%

– DIAGNOSIS'Preterm%Labor%STILL'UNCERTAIN%

– Triage'with%Fetal%FibronecOn%(fFN)%swab%to%lab%•  fFN'negaOve:%OBSERVE%for%4V6%hrs;%%

–  NO%cervical%change%–%PTL%ruled%out%–%DISCHARGE'–  IF'cervical%change%–%PTL%confirmed%–%ADMIT'&'TRANSFER'prn'

•  fFN'posiOve:%ADMIT%&%TRANSFER%prn%

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19%

INTERVENTIONS for fetal benefit

•  Magnesium sulfate if%<'32'weeks%%– Neonatal%neuroVprotecFon)%

•  Betamethasone%if%<'34'weeks%– Fetal%surfactant%sFmulaFon%

•  Tocolytic agents if'<'34'weeks%– Time%surfactant%sFmulaFon%&%transfer%to%NICU%

•  Antibiotics%if%<'36'weeks%– GBS%sepsis%chemoprophylaxis%

•  Neonatal neuro-protection (CP%&%death)%–  if%gestaFon%is%24 to 32 weeks –  If%imminent%delivery%anFcipated%(within%24%hr)%–  Infusion%duration:%>%4%hours%but%<%24%hours%–  Insufficient%evidence%for%repeated%infusions%

•  Dosage – 4%g%IV%loading%dose%with%1%g/hr%maintenance%–  (6%g%IV%loading%dose%with%2%g/hr%maintenance%or)%–  (4%g%IV%loading%dose%with%no%maintenance)%

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20%

•  Agents'and'dose'– Betamethasone:'12%mg%IM,%2%doses%24%hrs%apart%

–  Dexamethasone:'6%mg%IM,%4%doses%12%hrs%apart%

•  Benefit'primarily'seen'23-34 weeks –  Alveoli'need%to%be%present%in%the%lung%(>22%wks)%

•  Benefit'if'> 24 hr and < 7 days aker'1st'dose'

•  Give'if'high'risk'of'delivery'in next 7 days –  Clinical%judgement%

•  RDS%(ModVSevere)%%%down%45%%%(21%studies;%n=4000)%•  IVH%% % % %down%45%%%(6%studies;%n=1700)%•  NEC%% % % %down%55%%%(8%studies;%n=1700)%

•  NNM%%% % %down%30%%%(18%studies;%n=4000)%•  Systemic%InfecOon%%down%45%%%(5%studies;%n=1300)%

•  Avoid'if'contraindications'are'present'–  ConFnuaFon%of%pregnancy%is%harmful%to%Mom%or%fetus%%

•  Give'<'23'wks:'only'if'self-limited condiOon'–  Ruptured%appendiciFs%or%pyelonephriFs%

•  Avoid'after 34 wks:'risks'outweigh'benefits'•  Goal:'48 hr window for'perinatal'intervenOons'

–  steroid%effect,%MgSO4%&%maternal%transport%

•  Agent'selecOon:'–  24'to'32'wks:'Indomethacin'(1st)'then'nifedipine'(2nd)'–  32'to'34'wks:'Nifedipine'(1st)'then'terbutaline'(2nd)'

TOCOLYTIC%agents%

Agent

βaAdrenergic'Agonists'

Ca++'channel'blockers'

Side Effects

PG'synthetase'inhibitors'

MgSO4'

Ritodrine%removed%1998.%

Cochrane Review

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21%

Unproven Modalities for PTL

•  Intravenous ethanol for tocolysis •  Maintenance tocolysis •  Prophylactic tocolysis •  Routine bed rest •  Home Uterine Contraction monitoring •  Avoiding sexual activity •  Prophylactic antibiotics (no PROM)

Can%we%reduce%the%

preterm%birth%rate?%

YES!'

Rosie the pregnant riviter