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The check box: Determining pregnancy status to improve maternal mortality surveillance

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Abstract

Objective: More than half of pregnancy-related deaths are not identified through routine surveillance methods. The purpose of this study was to evaluate the effectiveness of the pregnancy check box on death certificates in ascertaining pregnancy-related deaths.

Methods: Data derived from the Centers for Disease Control and Prevention’s ongoing Pregnancy Mortality Surveillance System were used to identify states that included a check box on the death certificate in 1991 and 1992. Death certificates from those states were evaluated to determine the number and proportion of pregnancy-related deaths identified by a marked check box. Characteristics of death were also examined.

Results: Sixteen states and New York City included a check box or question specifically asking about pregnancy of the decedent. Of the 425 pregnancy-related deaths identified in the 17 reporting areas, 124 (29%) were determined to be pregnancy-related deaths only because of the pregnancy status information provided in the check box. The proportion of deaths identified only by a marked check box ranged from less than 5% for four states to 40% or more for seven states.

Conclusions: The availability of pregnancy status information on death certificates is a simple and effective aid in ascertaining a pregnancy-related death, when no other indicators of pregnancy appear on the death certificate. Routine use of the pregnancy check box for all states would lead to substantially increased classification of maternal deaths and more accurate classification of the causes of and risk factors for maternal deaths.

Introduction

D eaths of pregnant and recently pregnant women are an important public health concern, both nationally and internationally.1 In the United States, Healthy People 2000 2 specifies an overall goal of no more than 3.3 maternal deaths per 100,000 live births. This goal has never been met.3, 4, 5 Furthermore, studies have shown that more than half of pregnancy-related deaths are not identified through routine surveillance methods.6, 7, 8 Vital records remain the first line of maternal death identification. Women are often not identified on their death certificates as pregnant, recently pregnant, or having died as a consequence of pregnancy.9 Cause(s) of death listed on the certificate and coding requirements can lead to misclassification of maternal deaths by not indicating the role of pregnancy in the death.

In the Centers for Disease Control and Prevention (CDC), two centers collect data on maternal deaths. The National Center for Health Statistics (NCHS) reports maternal mortality including numbers, rates, and demographic information collected through the National Vital Statistics System as part of the mortality database. The Healthy People 2010 objective for maternal mortality is based on the maternal mortality rate as defined by NCHS. The Division of Reproductive Health (DRH) at the National Center for Chronic Disease Prevention and Health Promotion uses its Pregnancy Mortality Surveillance System (PMSS) to conduct epidemiologic surveillance of deaths related to pregnancy to provide detailed information on specific causes of death, outcomes of pregnancy, and potential risk factors for clinicians developing prevention strategies.

Section snippets

Background

Maternal mortality statistics, reported by NCHS since the early 1900s, are derived from information reported on death certificates for all deaths in the United States.10 NCHS codes causes of death, including maternal mortality, according to the classification systems and mortality coding rules of the World Health Organization (WHO) International Classification of Diseases, Ninth Revision (ICD-9).11 NCHS uses the ICD-9 definition of a “maternal death,” specified by WHO as “the death of a woman

Methods

We reviewed death certificates provided to DRH by the 50 states, New York City, and the District of Columbia to identify reporting areas that included a check box on the death certificate in 1991 and 1992. Death certificates from areas that employed a pregnancy check box were then evaluated to determine the number and proportion of pregnancy-related deaths identified by a marked check box. The cause of death, outcomes of pregnancy, intervals to death, and the availability of a matched live

Results

In 1991 and 1992, death certificates in 14 states and New York City included a pregnancy check box and two additional states without a check box asked about pregnancy status under “other significant conditions” (Table 1). Therefore, 17 reporting areas used a check box as defined in this study. The format for the pregnancy status item varied among the 17 areas. The postpregnancy time interval, i.e., the interval between the date when the pregnancy ended and the date when the woman died, used in

Discussion

PMSS data about pregnancy-related deaths have been analyzed to examine the risk of pregnancy mortality by age, race, education, live-birth order, marital status, cause of death, and outcome of pregnancy.9, 12Other reports include studies of pregnancy mortality associated with abortion13 and acquired immunodeficiency syndrome,14 the risk of pregnancy mortality among older women,15 and the relationship between hospital size and the comparative safety of childbearing.16 The findings in these

Acknowledgements

The authors acknowledge Harry Rosenberg, PhD, and George A. Gay, MSPH, of the Division of Vital Statistics, National Center for Health Statistics, Centers for Disease Control and Prevention, for their valuable assistance with this project.

References (18)

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