timing of elective repeat cesarean delivery at term and neonatal outcomes

Timing of Elective Repeat Timing of Elective Repeat Cesarean Delivery at Term Cesarean Delivery at Term and Neonatal Outcomesand Neonatal Outcomes

David Guernsey MDDavid Guernsey MD

Case ScenarioCase Scenario 26 yo G4P2 female at 36 weeks who has 26 yo G4P2 female at 36 weeks who has

had a prior low transverse cesarian sectionhad a prior low transverse cesarian section She has be an L&D 3 times already in the She has be an L&D 3 times already in the

last 2 weeks and has called or been in the last 2 weeks and has called or been in the office 2 times a week. office 2 times a week.

““Dr Guernsey this baby is kicking my butt, Dr Guernsey this baby is kicking my butt, I’m having a C-section, why can’t we just I’m having a C-section, why can’t we just take this baby out next week since I’ll be take this baby out next week since I’ll be full term”full term”

Why shouldn’t I just do the C-Why shouldn’t I just do the C-section next week? section next week?

She will be full term right…She will be full term right…

Million Dollar QuestionMillion Dollar Question Does it make any difference in fetal Does it make any difference in fetal

outcomes if I perform a cesarean outcomes if I perform a cesarean section at 37 weeks versus 40 weeks section at 37 weeks versus 40 weeks in a healthy uncomplicated in a healthy uncomplicated pregnancy?pregnancy?

Study DesignStudy Design COHORT STUDYCOHORT STUDY Used the cesarean Used the cesarean

registry from the Eunice registry from the Eunice Kennedy Shriver National Kennedy Shriver National Institute of Child Health Institute of Child Health and Human Development and Human Development Maternal-Fetal Medicine Maternal-Fetal Medicine Units NetworkUnits Network

19 academic centers19 academic centers Data from 1999-2002Data from 1999-2002

Patient Patient SelectionSelection

28,867 repeat C-28,867 repeat C-sectionsection

24,077 had term C-24,077 had term C-sectionssections

13,258 patients had 13,258 patients had term repeat C-term repeat C-sections with no sections with no indication for indication for immediate deliveryimmediate delivery

Separation by gestational Separation by gestational weeksweeks

6.3% delivered at 37 weeks6.3% delivered at 37 weeks 29.5% delivered at 38 weeks29.5% delivered at 38 weeks 49.1% delivered at 39 weeks49.1% delivered at 39 weeks 15% delivered at 40 weeks or later15% delivered at 40 weeks or later

Patients <39 weeks were usually Patients <39 weeks were usually older, lower BMI, white, married, older, lower BMI, white, married, insured, had a 1insured, had a 1stst trimester sono trimester sono

Outcome MeasurementsOutcome Measurements DeathDeath Adverse respiratory outcomes (RDS, transient tachypnea of Adverse respiratory outcomes (RDS, transient tachypnea of

the newborn)the newborn) HypoglycemiaHypoglycemia SepsisSepsis SeizuresSeizures Necrotizing entercolitisNecrotizing entercolitis Hypoxic-ischemic encephalopathyHypoxic-ischemic encephalopathy CPRCPR Ventalation support within 24 hoursVentalation support within 24 hours Umbilical pH below 7Umbilical pH below 7 5 minute APGAR below 35 minute APGAR below 3 NICU admissionNICU admission Prolonged hospitalization (over 5 days)Prolonged hospitalization (over 5 days)

AnalysisAnalysis Incidence of an adverse outcome Incidence of an adverse outcome

decreased from 37-39 weeksdecreased from 37-39 weeks 15.3% @37wks15.3% @37wks 11.0% @38wks11.0% @38wks 8.0% @39wks8.0% @39wks 7.3% @40wks7.3% @40wks

Incidence of an adverse outcome Incidence of an adverse outcome increased after 40 weeksincreased after 40 weeks 11.3% @41wks11.3% @41wks 19.5% @42wks19.5% @42wks

Odds RatioOdds RatioCompares disease in exposed and Compares disease in exposed and

nondisease in unexposed populations with nondisease in unexposed populations with disease in unexposed and nondisease in disease in unexposed and nondisease in exposed populations to determine if there exposed populations to determine if there is a difference in the two. (A X D)/(B X C)is a difference in the two. (A X D)/(B X C)

Compared neonatal outcomes and Compared neonatal outcomes and

gestational age at delivery relative to 39 gestational age at delivery relative to 39 weeksweeks

Odds RatiosOdds Ratios

Attributable RiskAttributable Risk Number of cases attributable to one Number of cases attributable to one

risk factorrisk factor (A/(A+B))-(C/(C+D)) OR(A/(A+B))-(C/(C+D)) OR [(relative risk-1)/relative risk] X100[(relative risk-1)/relative risk] X100

Where RR=[A/(A+B)]/[C/(C+D)]Where RR=[A/(A+B)]/[C/(C+D)]

Attributable RiskAttributable Risk Attributable Risk at 37 weeks is 48%Attributable Risk at 37 weeks is 48% Attributable Risk at 38 weeks is 27%Attributable Risk at 38 weeks is 27%

Study LimitationsStudy Limitations Smaller population of patients delivered Smaller population of patients delivered

at 37 weeksat 37 weeks Accuracy of determining estimated Accuracy of determining estimated

gestational age (1gestational age (1stst vs 2 vs 2ndnd trimester trimester sonograms)sonograms)

Study does not asses fetal lung maturityStudy does not asses fetal lung maturity Study does not asses effect of stillbirthsStudy does not asses effect of stillbirths

Why do I care?Why do I care? Over 1/3 of elective cesarean Over 1/3 of elective cesarean

sections are before 39 weekssections are before 39 weeks Many of us are going to towns where Many of us are going to towns where

we will be deciding when to do our we will be deciding when to do our patients cesarean sectionspatients cesarean sections

All of us have whiney patientsAll of us have whiney patients

ConclusionsConclusions My kids are cuter than yours!My kids are cuter than yours!