Classification of Pregnancy-Related

Mortality based on Death Certificate

versus Medical Chart Review Michigan, 1990-1998

Joanne G. Hogan, PhDBao-Ping Zhu, MD, MS

Division of Epidemiology ServicesCommunity Public Health Agency

Michigan Department of Community Health

Background

• U.S. maternal mortality among the highest in industrialized nations

• No decline since 1982• Statistics based on Death certificate

– ICD-9 630 - 676

• World Health Organization Definition• Death within 42 days of end of pregnancy• Due to complications of pregnancy• Chain of events initiated by pregnancy• Aggravation by physiologic or pharmacological effects

of pregnancy

Goal of Study

Improve Identification,

Classification and Knowledge

of Pregnancy-Related Deaths

Methods

Review medical charts and supporting documentation to compare

classifications

Death Certificate and

Michigan Maternal Mortality Study Medical Review Committee

Study Definition and Data Sources

Maternal death: – Death matched to live birth in previous 365

days– Death of woman while pregnant

Reporting sources for maternal deaths– Hospitals– Medical Examiners– Michigan Department of Community Health,

Division of Vital Records

Pregnancy-Associated and Related Mortality Ratio by Race, Death Certificate

NumberMortality Ratio

(/100,000 live births)

Pregnancy-Associated516 41.0 White 269 27.4 Black 228 92.8

Pregnancy-Related 90 7.1 (.ICD-9 630-376 on birth certificate-365 days)

White 33 3.4 Black 53 21.6

Black/White Ratio 6.4

Cases Reviewed

Number Percent

Selected for Review 232 44.9%

Reviewed 217 93.5%

No chart available 13 5.6%

Awaiting review 2 0.1%

Classified Pregnancy- 169 77.9%Related by MMMS Committee

Death Certificate Pregnancy-Related Cause Committee Reclassification

Pregnancy-Related - DC Total 90Selected for Review 86 95.5%

No chart/awaiting review 5 5.8%

DC/Committee Agreement 77 89.5%

Reclassified Unrelated 2 2.3%(1 Black, 1 Native American)

Reclassified Undetermined 2 2.3%(2 Black)

Characteristics of Reclassified CasesPregnancy-Related on Death Certificate

Death Certificate Cause Committee Cause

Abortion/spontaneous Ventricular fibrillationand induced (3) Cardiac arrest

Bacteremia

Obstetric air embolism (1) Pulmonary embolism

Characteristics of Reclassified CasesPregnancy-Related on Death Certificate

Number Number

Time of DeathNo Live Birth 3 >42 days 1

Autopsy Yes 3 No 1

Place of Death DOA/ER 3 Inpatient 1

Prenatal Care Yes 1 No 3(Native American 1) (Black 3)

Reclassification of Death CertificateNon-pregnancy-Related Cause

Number Percent

Total cases reviewed 217

Classified Pregnancy-Related by Committee 169 77.9%

Reclassified from Death Certificate by Committee as Pregnancy-Related 92 70.2%

Reclassified Cases - CauseNon-Pregnancy-Related on Death Certificate

No patterns for

Race Prenatal carePlace of Death Time to deathResidence Birth attendantEducation Birth placeBirth outcome Payment

sourceMedical risk factorsComplications of pregnancy

Characteristics of Reclassified CasesNon-Pregnancy-Related on Death Certificate

Percent of Death certificates coded as underlying cause

Reviewed Reclassified

Circulatory System 56.5% 56.2%

Respiratory System 12.3% 83.3%

Reclassification of remaining reviewed causes evenly distributed

Pregnancy-Related Mortality Ratio by RaceCommittee Review

NumberMortality Ratio

(/100,000 live births)

Total 169 13.4

White 73 7.4

Black 91 37.0

Black/White Ratio 5.0

Comparison of Black/White Ratio Committee Review and Death CertificatePregnancy-Related deaths, three-year running average

0

1

2

3

4

5

6

7

8

9

90-92 91-93 92-94 93-95 94-96 95-97 96-98

Bla

ck/W

hite

Rat

io

Death Certifi cate

Committee

Black/White Ratio by Age Group Committee Review and Death Certificate

0

2

4

6

8

10

12

14

<20 20-29 30-39

Age Group

Bla

ck/W

hite

Rat

io

Death Certifi cate

Committee

Time of Pregnancy-Related Death by RaceDeath Certificate

White

<=42

days

55%

>42 days

15%

No Live

Birth

30%

Black

No Live

Birth

40%

<=42

days

54%

>42 days

6%

Time of Pregnancy-Related Death by RaceCommittee Review

White

<=42

days

56%

No

Live

Birth

27%

>42

days

17%

Black

<=42

days

64%

>42

days

9%

No

Live

Birth

27%

Study Limitations

Inability to identify all cases

Small numbers of events for

analysis

Summary

Reclassification as pregnancy -related

• resulted in a decrease of the black/white discrepancy

• Increased identification of black and white women with circulatory system complications

• Decreased racial discrepancy for pregnancy-loss

Public Health Recommendations

Increase information to physicians about need to specify pregnancy on death certificate

Increase information to physicians and women at risk about cardiovascular compromise in pregnancy-related mortality