Infant Mortality and Infant Mortality and Issues Relating to Issues Relating to Perinatal ReportingPerinatal Reporting

U.S. Department of Health and Human ServicesCenters for Disease Control and Prevention

National Center for Health StatisticsNational Vital Statistics System

AcknowledgementsAcknowledgements

Joyce A. Martin, M.P.H.Marian MacDorman, Ph.DDonna L. Hoyert, Ph.D.Ken Kochanek, M. A.Stephanie Ventura, M.A.

NATIONAL VITAL NATIONAL VITAL STATISTICS SYSTEMSTATISTICS SYSTEM

Live births Fetal deaths

(>20 weeks) Infant deaths

(to age 1)

Certificate of Live birth

Certificate of Death

Report of Fetal Death

Model State Vital Statistics Act Model State Vital Statistics Act and Regulations - Definitionsand Regulations - Definitions

Live birth - “…breathes or shows any evidence of life such as beating of the heart…heartbeats are to be distinguished from transient cardiac contractions; respirations…from fleeting efforts…”

Fetal Death - “… death prior to [delivery]…is 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.

Reporting issues which might affect Reporting issues which might affect changes in infant mortality rateschanges in infant mortality rates

Changes in reporting of infantinfant deaths <500 grams,

i.e., improved reporting of deaths of very small live-born infants

Reporting issues which might affect Reporting issues which might affect changes in infant mortality rateschanges in infant mortality rates

Changes in reporting of deliveries at “borderline of viability”

i.e., increased tendency to report delivery as live birth rather than fetal death

Trends inTrends inbirth characteristicsbirth characteristics

Infant mortality rates by Infant mortality rates by birthweight: United States, 2002birthweight: United States, 2002

862.0

489.0

155.1

70.3 45.7 26.5 11.5 2.40.0

100.0

200.0

300.0

400.0

500.0

600.0

700.0

800.0

900.0

1000.0

<500 500-749

750-999

1000-1249

1250-1499

1500-1999

2000-2499

2500+

Per

1,0

00 l

ive

bir

ths

grams

Preterm and low birthweight rates: Preterm and low birthweight rates: U.S., 1981-2002U.S., 1981-2002

5

10

15

1981 1985 1990 1995 2000 2002

Pe

rce

nt

NOTE: Preterm is less than 37 completed weeks of gestation. Low birthweight is less than 2,500 grams.SOURCE: National Vital Statistics System, NCHS, CDC.

Low birthweight (<2,500 grams)

Preterm (<37 weeks)

0

Distribution of births by gestational Distribution of births by gestational age: U.S., 1990 and 2002age: U.S., 1990 and 2002

0

5

10

15

20

25

30

26 28 30 32 34 36 38 40 42 44 47

Completed weeks of gestation

Pe

rce

nt 1990

2002

Less than 24

Percent of live births <500 and Percent of live births <500 and <750 grams: 1990, 1995, 2001 and 2002<750 grams: 1990, 1995, 2001 and 2002

0.134 0.139 0.149 0.148 0.156

0.228 0.253 0.282 0.271 0.276

0

0.1

0.2

0.3

0.4

0.5

0.6

1990 1995 1999 2001 2002

Per

cen

t

0.4320.4190.392

<500 gm 500-749 gm

0.3620.432

Preterm and low birthweight ratesPreterm and low birthweight ratesby plurality: U.S., 2002by plurality: U.S., 2002

0

10

20

30

40

50

60

70

80

90

100

Singletons Twins Triplet/+ Singletons Twins Triplet/+

Pe

rce

nt

SOURCE: National Vital Statistics System, NCHS, CDC.

Low birthweightPreterm

10.1

94.7

55.4

6.1

92.7

58.2

Very preterm/low birthweight Moderately preterm/low birthweight

Percent low birthweight for all birthsPercent low birthweight for all birthsand for singletons only: U.S., 1980-2002and for singletons only: U.S., 1980-2002

4

6

8

10

1980 1985 1990 1995 2000 2002

Pe

rce

nt

NOTE: Low birthweight is less than 2,500 grams.SOURCE: National Vital Statistics System, NCHS, CDC.

All births/pluralities

Singletons

0

Reporting & trends in fetal mortality

Reporting requirementsReporting requirementsfor fetal deathsfor fetal deaths

Model Law recommends 350 grams/20 wksModel Law recommends 350 grams/20 wks

All products of conception 7 StatesAll 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

Early and late fetal mortality rates: Early and late fetal mortality rates: U.S. 1990-2002U.S. 1990-2002

0

2

4

6

1990 1995 2000 2002

Rat

e p

er 1

,000

live

bir

ths

+ f

etal

dea

ths

Late fetal (28+ weeks)

Early fetal (20-27 weeks)

Source: National Vital Statistics System, NCHS, CDC.

Early fetal mortality rate = fetal deaths with stated or presumed gestationalages of <28 weeks per 1,000 live births plus fetal deaths. Late fetal mortalityrate = deaths with stated or presumed gestational ages of 28 weeks or moreper 1,000 live births plus fetal deaths.

Percent of fetal deaths 20+ weeks <500 Percent of fetal deaths 20+ weeks <500 grams and <750 grams: 1990, 1995, 2001 grams and <750 grams: 1990, 1995, 2001 and 2002and 2002

24.8 29.4 33.3 32.8 34

15.615 15 14.6

15.9

0

10

20

30

40

50

60

1990 1995 1999 2001 2002

Per

cen

t

48.547.745.0

<500 gm 500-749 gm

40.748.3

Percent of all fetal deaths 20+ weeks that occur at 20-27 Percent of all fetal deaths 20+ weeks that occur at 20-27 weeks: States reporting all periods of gestation and all weeks: States reporting all periods of gestation and all other States, Selected yearsother States, Selected years

5241

5646

5848

5749

0

10

20

30

40

50

60

Pe

rce

nt

All periods States All other States

22% gap 18% gap 17% gap 14% gap

1990 1995 2001 2002

Trends in infant mortality

Infant mortality rate: Infant mortality rate: United States, 1940-2001United States, 1940-2001

0

20

40

60

1940 1950 1960 1970 1980 1990 2001

De

ath

s u

nd

er

1 y

ea

r p

er

1,0

00

liv

e b

irth

s

SOURCE: National Vital Statistics System, NCHS, CDC.

Infant mortality rate: Infant mortality rate: United States, 1990-2002United States, 1990-2002

5

6

7

8

9

10

1990 1992 1994 1996 1998 2000 2002*

De

ath

s u

nd

er

1 y

ea

r p

er

1,0

00

liv

e b

irth

s

0

* Preliminary data.

SOURCE: National Vital Statistics System, NCHS, CDC.

+3%

Infant mortality rates by Infant mortality rates by birthweight: United States, 2002birthweight: United States, 2002

862.0

489.0

155.1

70.3 45.7 26.5 11.5 2.40.0

100.0

200.0

300.0

400.0

500.0

600.0

700.0

800.0

900.0

1000.0

<500 500-749

750-999

1000-1249

1250-1499

1500-1999

2000-2499

2500+

Per

1,0

00 l

ive

bir

ths

grams

Infant deaths and infant, neonatal, and Infant deaths and infant, neonatal, and postneonatal mortality rates: United postneonatal mortality rates: United States, preliminary 2002, and final 2001States, preliminary 2002, and final 2001

[Rates per 1,000 live births]

Infant mortality rate

Infantdeaths

Neonatal (Under 28 days) Postneonatal (28 days – 11 months)Year Total Total

Under 7 days

7-27 days

2002 1 28,042 7.0 4.7 3.7 0.9* 2.3

2001 27,568 6.8 4.5 3.6 0.9 2.3

1 Partially edited data processed through January 2004.*2001 =0.908, 2002 = 0.931

NOTE: Bold underlined numbers indicate a statistically significant increase from the previous year.SOURCE: National Vital Statistics System, NCHS, CDC.

Early and late neonatal and postneonatal Early and late neonatal and postneonatal mortality rates: U.S., 1990-2002mortality rates: U.S., 1990-2002

0

1

2

3

4

5

6

1990 1995 2000 2002

Ra

te p

er

1,0

00

liv

e b

irth

s

Note: Rates for 2002 are based on partially edited data processed as of January, 2004.

Postneonatal (28+ days)

Late neonatal (7-27 days)

Early neonatal mortality rate = deaths to infant < 7 days per 1,000 live births. Late neonatal mortality rate = deaths to infants 7-27 days. Postneonatal mortality rate = deaths to infants 28 days - 1 year per 1,000 live births.

Source: National Vital Statistics System, NCHS, CDC.

Early neonatal (<7 days)

Percent of perinatal events* <750 Percent of perinatal events* <750 grams: 2001 and 2002grams: 2001 and 2002

0.327 0.340

0.2200.218

0.0

1.0

2001 2002

Pe

rce

nt

0.545 0.560

<500 gm 500-749 gm

* Includes fetal deaths of 20+ weeks of gestation plus live births of all gestational ages.

Infant mortality rates <500 g. Infant mortality rates <500 g. birthweight, Selected States, 2002birthweight, Selected States, 2002

636.0 692.1 698.1 703.1

963.0 970.3 973.8 1000.0

0

100

200

300

400

500

600

700

800

900

1000

A B C D W X Y ZState

IMR

Includes the four states with the highest and lowest rates in 2002, which also had at least 20 births <500 grams.

How might reporting improvements How might reporting improvements be made?be made?

• Active follow-back on < 750gm births

• Better support of fetal death reporting

• Modification of state law on fetal death reporting

• Re-engineering

But Why Re-engineering?But Why Re-engineering?

• Automated linkage - improve surveillance of borderline events

• Keep birth and fetal death report of the same event from happening

• Fetal event is rare … hard to capture via a seldom used paper report.

• Improved understanding of the importance for reporting fetals