U'S' Trends in Infant and Fetal Mortality

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U.S. Trends in Infant and Fetal Mortality
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Authors / Acknowledgements

• Joyce A. Martin, M.P.H.
• Marian MacDorman, Ph.D
• Donna L. Hoyert, Ph.D.
• Ken Kochanek, M. A.

Presented to the State Infant Mortality
Collaborative Meeting, 9/20/04
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NATIONAL VITAL STATISTICS SYSTEM
Certificate of Live birth

• Live births
• Fetal deaths
• (gt20 weeks)
• Infant deaths
• (to age 1)

Report of Fetal Death
Certificate of Death
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Model State Vital Statistics Act and Regulations
- Definitions

• Live birth - breathes or shows any evidence of
  life such as beating of the heartheartbeats are
  to be distinguished from transient cardiac
  contractions respirationsfrom fleeting
  efforts
• Fetal Death - death prior to deliveryis not
  an induced termination of pregnancy does not
  breathe or show any other evidence of life
• Infant Death - death of a live born infant within
  one year of life.

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Trends inbirth characteristics
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Preterm and low birthweight rates U.S., 1981-2002
0
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Percent of live births lt500 and lt750 grams
1990, 1995, 2001 and 2002

lt500 gm
500-749 gm
0.432
0.432
0.419
0.392
0.362
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Infant mortality rates by birthweight U.S., 2001
grams
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Twin and triplet birth rates United States,
1980-2002
Twin
Triplet
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Preterm and low birthweight ratesby plurality
U.S., 2002
Very preterm/low birthweight
Moderately preterm/low birthweight
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Percent low birthweight for all birthsand for
singletons only U.S., 1980-2002
0
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Infertility Therapies

• Increased risk
• of multiple births
• Increased risk
• of preterm/lbw
• singleton births ?

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Rates of induction of labor bylength of
gestation U.S., 1990-2002
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Rates of cesarean delivery by lengthof
gestation United States, 1990-2002
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Trends in fetal mortality
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Early and late fetal mortality rates U.S.
1990-2002
Early fetal mortality rate fetal deaths with
stated or presumed gestational ages of lt28 weeks
per 1,000 live births plus fetal deaths. Late
fetal mortality rate deaths with stated or
presumed gestational ages of 28 weeks or more per
1,000 live births plus fetal deaths.
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Percent of fetal deaths 20 weeks lt500 grams and
lt750 grams 1990, 1995, 2001 and 2002

lt500 gm
500-749 gm
48.5
47.7
48.3
45.0
40.7
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Reporting requirementsfor fetal deaths

• Model Law recommends 350 grams/20 wks
• All products of conception 7 States
• 16 weeks 1
  State
• 20 weeks or more/350 grams 39 States
• 500 grams or more 3
  States
• District of Columbia 20 wks or 500 grams

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Percent of fetal deaths 20 weeks that occur at
lt28 weeks States reporting all periods of
gestation and all other States, Selected years

All periods States
All other States
22 gap
18 gap
17 gap
14 gap
1990
1995
2001
2002
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Trends in infant mortality
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Infant mortality rate United States, 1940-2001
SOURCE National Vital Statistics System, NCHS,
CDC.
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Infant mortality rate United States, 1990-2002

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SOURCE National Vital Statistics System, NCHS,
CDC.
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Infant deaths and infant, neonatal, and
postneonatal mortality rates United States,
preliminary 2002, and final 2001
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Early and late neonatal and postneonatal
mortality rates U.S., 1990-2002
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Infant mortality rates by leading causes United
States, preliminary 2002, and final 2001
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Percent of all infants born LBW and neonatal
mortality rates among LBW infants U.S., 1990,
1995, 2001
Neonatal mortality at lt2,500 grams
Percent of infants lt2,500 grams
LBWlt2,500 grams Source National Vital
Statistics System, CDC, NCHS.
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Reporting issues which may affect changes in
infant mortality rates

• Changes in reporting of infant deaths lt500
  grams,
• i.e., improved reporting of deaths of very small
  live-born infants

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Percent of reported non-survivorslt500 gm
Selected States, 2002and the U.S., 1995, 2001
and 2002
Selected States, 2001
U.S., 1995, 2000, 2001
Source National Vital Statistics System, CDC,
NCHS.
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Reporting issues which may affect changes in
infant mortality rates

• Changes in reporting of deliveries at
  borderline of viability
• (Born-alive infants protection Act?)
• i.e., increased tendency to report delivery as
  live birth rather than fetal death

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Stay tuned.

• Data from the Linked Birth/Infant Death Data Set
  will allow us to more fully explain this
  troubling change in infant mortality for 2002
• Scheduled for release fall of 2004

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Re-engineered vital statistics systems

• More immediate, more thorough analysis
• More timely, higher quality data
• Data released within months of event
• Electronic death reporting - Births/infant deaths
  automatically linked data available
  simultaneously
• New, improved items
• Pregnancy risk factors - Infertility therapies,
  Infections
• Method of delivery - attempted trial of labor