Fetal Death Certificates as a Source of Surveillance Data for Stillbirths with Defects

1
Fetal Death Certificates as a Source of
Surveillance Data for Stillbirths with Defects

• Wes Duke, MD MPH Adolfo Correa, MD PhD CJ
  Alverson, MS

The findings and conclusions in this report have
not been formally disseminated by the CDC and
should not be construed to represent any agency
determination or policy.
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Definitions

• WHO Fetal Death
• Death prior to the complete expulsion or
  extraction from the mother of a product of
  conception, irrespective of the duration of
  pregnancy. The death is indicated by the fact
  that after such separation, the fetus does not
  breath or show any other evidence of life, such
  as beating of the heart, pulsation of the
  umbilical cord or definite movement of voluntary
  muscles.
• Stillbirth Intrauterine fetal death at 20 weeks
  gestation or 350 grams if gestational age is
  unknown.
• No single universal definition for cutoffs

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Fetal Death Reporting

• Fetal death is a reportable event in all 50
  states and U.S. territories
• Reporting requirements vary
• Model Law seeks to promote uniformity in
  reporting

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IntroductionStillbirth

• One of the most common adverse pregnancy outcomes
• Occur 10 times more often than sudden infant
  death (SIDS)
• Account for nearly one half of all perinatal
  mortality
• Remain a largely understudied pregnancy outcome

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Public Health Relevance U.S. Perinatal
mortality rates 1950 - 2002
Per 1000 births
____________________________ Martin et al. Natl
Vital Stat Rep 2003
Year
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Fetal Death Certificates (FDCs)

• Under-reporting
• Greb, Pauli, et al. AJPH, 1987
• Goldhaber AJPH, 1989
• MacDorman et al. NVSR 563 2007
• Item completeness
• Martin, Hoyert Sem Peinat, 2002
• Accuracy/reliability of recorded data
• Lydon-Rochelle et al. AJPH, 2005
• Lack of uniform post-mortem evaluations
• Pauli et al. AJMG, 1994
• Misclassification

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Objectives

• Use a population-based birth defects surveillance
  program
• To evaluate the ascertainment of stillbirths with
  birth defects in FDCs
• To assess the quality and validity of information
  found on FDCs with respect to stillbirths with
  birth defects

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Methods

• Study population (N257)
• Metropolitan Atlanta Congenital Defects Program
• Stillbirths with birth defects
• 1994 2002
• Data linkage
• Cases in MACDP linked to FDCs for the same birth
  cohort
• Deterministic matching process mothers name,
  race, address and county of residence, fathers
  name, fetal sex, date of event, and hospital
• Live birth certificates for cases not linked

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Methods MACDP
Established 1967 Population-based Active
case finding Monitors births to 5-county
residents gt 50,000 live births/yr Modified
BPA coding of defects

MACDP Metropolitan Atlanta Congenital Defects
Program
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MethodsAnalysis

• Issuance of a FDC
• Predictors using multivariate logistic regression
  modeling
• Maternal age, race/ethnicity, gestational age,
  birth weight, county, hospital, autopsy status
  and selected birth defect classes
• Concordance of information
• Cases with records in MACDP and FDC
• Maternal age, gestational age, birth weight,
  amniocentesis,
• Defects anencephaly, spina bifida, cleft
  lip/palate, Down syndrome, heart defects,
  omphalocele, renal agenesis

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Results1994 - 2002
MACDP
13,798 Cases with defects
13,275 (96.2 ) Live births
257 (1.9 ) Stillbirths
266 (1.9 ) Terminations
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Results1994 - 2002
MACDP
13,798 Cases with defects
Vital Records
13,275 (96.2 ) Live births
Total live births 407,155 Total stillbirths
4050
257 (1.9 ) Stillbirths
266 (1.9 ) Terminations
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MACDP Cases Reported to Vital Records 1994 -
2002
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MACDP Cases Reported to Vital Records 1994 -
2002
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Characteristics of Cases with No FDC
Compared with Cases Issued a FDC MACDP, 1994 -
2002
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Characteristics of Cases with No FDC
Compared with Cases Issued a FDC MACDP, 1994 -
2002
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Characteristics of Cases with No FDC
Compared with Cases Issued a FDC MACDP, 1994 -
2002
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Crude and Adjusted Odds Ratios for a Case Being
Issued a FDC MACDP, 1994 - 2002
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Variable Concordance MACDP vs. FDC, 1994 - 2002
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Sensitivity and Positive Predictive Value of FDCs
for Selected Defects Compared with MACDP, 1994 -
2002
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Summary

• FDCs captured 13 fewer stillbirths with defects
  than MACDP
• Issuance of a FDC appeared to be non-random
• Concordance of information varied
• Good agreement for some core demographic info
• Poor agreement and reliability for certain
  defects and amniocentesis

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Strengths/Limitations

• Strengths
• Population-based
• Active ascertainment
• Multiple sources
• Trained abstractors
• Detailed coding manual for defects

• Limitations
• Small numbers
• Limited to stillbirths with defects
• Results can not be generalized to all stillbirths

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Public Health Implications

• Population-based etiologic studies on stillbirth
  are needed
• Limitations of fetal death records
• Expansion of existing birth defects surveillance
  programs could potentially enhance the data
  derived from FDCs
• Further pilot studies are underway to assess the
  feasibility of this novel approach

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Acknowledgements

• Don Gambrell assistance with data linkage
• MACDP abstractors

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Thank You
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Birth Weight in MACDP vs. FDC,1994 - 2002