Andrea P. MacKay

Identification of severe maternal morbidity during delivery hospitalizations, United States, 1991-2003.

OBJECTIVE This investigation aimed to identify pregnancy complications and risk factors for women who experienced severe maternal morbidity during the delivery hospitalization and to estimate severe maternal morbidity rates. STUDY DESIGN We used the National Hospital Discharge Survey for 1991-2003 to identify delivery hospitalizations with maternal diagnoses and procedures that indicated a potentially life-threatening diagnosis or life-saving procedure. RESULTS For 1991-2003, the severe maternal morbidity rate in the United States was 5.1 per 1000 deliveries. Most women who were classified as having severe morbidity had an ICD-9-CM code for transfusion, hysterectomy, or eclampsia. Severe morbidity was more common at the extremes of reproductive age and for black women, compared with white women. CONCLUSION Severe maternal morbidity is 50 times more common than maternal death. Understanding these experiences of these women potentially could modify the delivery of care in healthcare institutions and influence maternal health policy at the state and national level.

Overview of maternal morbidity during hospitalization for labor and delivery in the United States: 1993-1997 and 2001-2005.

OBJECTIVE: To assess progress toward meeting the U.S. Healthy People 2010 objective of reducing the rate of maternal morbidity at delivery hospitalization by comparing National Hospital Discharge Survey data from two time periods. METHODS: Using data from the National Hospital Discharge Survey, we estimated rates of intrapartum morbidity defined by obstetric complications, preexisting medical conditions, and cesarean delivery during 2001–2005 and compared them with rates published for 1993–1997. We calculated and compared the rates for categories of morbidity as well as rates for the summary groups of morbidity. RESULTS: Between the two time periods, the rate of obstetric complications remained unchanged at 28.6%; the prevalence of preexisting medical conditions at delivery increased from 4.1% to 4.9%. Rates of chronic hypertension and preeclampsia, gestational and preexisting diabetes, asthma, and postpartum hemorrhage increased, whereas rates of third- and fourth-degree lacerations and various types of infection decreased. The cesarean delivery rate increased from 21.8% to 28.3%. CONCLUSION: Between 1993–1997 and 2001–2005, the rate of intrapartum morbidity associated with obstetric complications was unchanged and the rate of pregnancies complicated by preexisting medical conditions increased. LEVEL OF EVIDENCE: II

Tubal sterilization in the United States, 1994-1996

CONTEXT Although the number and rate of tubal sterilizations, the settings in which they are performed and the characteristics of women obtaining sterilization procedures provide important information on contraceptive practice and trends in the United States, such data have not been collected and tabulated for manyyears. METHODS Information on tubal sterilizations from the National Hospital Discharge Survey and the National Survey of Ambulatory Surgery was analyzed to estimate the number and characteristics of women having a tubal sterilization procedure in the United States during the period 1994-1996 and the resulting rates of tubal sterilization. These results were compared with those of previous studies to examine trends in clinical setting, in the timing of the procedure and in patient characteristics. RESULTS In 1994-1996, more than two million tubal sterilizations were performed, for an average annual rate of 1 1.5 per 1,000 women; half were performed postpartum and half were interval procedures (i. e., were unrelated by timing to a pregnancy). All postpartum procedures were performed during inpatient hospital stays, while 96% of interval procedures were outpatient procedures. Postpartum sterilization rates were higher than interval sterilization rates among women 20-29 years of age; interval sterilization procedures were more common than postpartum procedures at ages 35-49. Sterilization rates were highest in the South. For postpartum procedures, private insurance was the expectedprimary source of payment for 48% and Medicaid was expected to pay for 41 %; for interval sterilization procedures, private insurance was the expected primary source of payment for 68% and Medicaid for 24%. CONCLUSIONS Outpatient tubal sterilizations andprocedures using laparoscopy have increased substantially since the last comprehensive analysis of tubal sterilization in 1987, an indication of the effect of technical advances on the provision of this service. Continued surveillance of both inpatient and outpatient procedures is necessary to monitor the role of tubal sterilization in contraceptive practice.

Pregnancy-related mortality among women with multifetal pregnancies.

OBJECTIVE: To examine the relative risk of pregnancy-related mortality between multifetal pregnancies and singleton pregnancies. METHODS: We used data from the Centers for Disease Control and Prevention’s Pregnancy Mortality Surveillance System to examine singleton and multifetal pregnancy-related deaths among women with a live birth or fetal death from 1979–2000. The plurality-specific (singleton or multifetal) pregnancy-based mortality ratio was defined as the number of pregnancy-related deaths per 100,000 pregnancies with a live birth. We analyzed the risk of death due to pregnancy for singleton and multifetal pregnancies by age, race, education, marital status, and cause of death. RESULTS: Of 4,992 pregnancy-related deaths in 1979–2000, 4.2% (209 deaths) were among women with multifetal pregnancies. The risk of pregnancy death among women with twin and higher-order pregnancies was 3.6 times that of women with singleton pregnancies (20.8 compared with 5.8). The leading causes of death were similar for women with singleton pregnancies and women with multifetal pregnancies: embolism, hypertensive complications of pregnancy, hemorrhage, and infection. CONCLUSION: Women with multifetal pregnancies have a significantly higher risk of pregnancy-related death than their counterparts with singleton pregnancies; this holds true for all women regardless of age, race, marital status, and level of education. LEVEL OF EVIDENCE: II-2

Pregnancy-related mortality in the United States due to hemorrhage: 1979–1992

OBJECTIVE To study trends and examine risk factors for pregnancy-related mortality due to hemorrhage. METHODS We analyzed pregnancy-related deaths from 1979-1992 from the National Pregnancy Mortality Surveillance System of the Centers for Disease Control and Prevention. Live-birth data used to calculate mortality ratios were obtained from published vital statistics. Deaths due to ectopic pregnancies were excluded. RESULTS There were 763 pregnancy-related deaths from hemorrhage associated with intrauterine pregnancies, a ratio of 1.4 deaths per 100,000 live births. The pregnancy-related mortality ratio was higher for black women and those of other races than white women. The risk of pregnancy-related mortality increased with age. Abruptio placentae was the overall leading cause of pregnancy-related death due to hemorrhage. Leading causes of death differed by race, age group, and pregnancy outcome. CONCLUSION Hemorrhage is the leading cause of pregnancy-related death in the United States. Black women have three times the risk of death of white women. In-depth investigations are needed to ascertain the risk factors associated with those deaths.

The check box: determining pregnancy status to improve maternal mortality surveillance.

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 Preventions 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.

Changes in pregnancy mortality ascertainment: United States, 1999-2005.

OBJECTIVE: To estimate mortality ratios for all reported pregnancy deaths in the United States, 1999–2005, and to estimate the effect of the 1999 implementation of International Classification of Diseases, Tenth Revision (ICD-10) and adoption of the U.S. Standard Certificate of Death, 2003 Revision, on the ascertainment of deaths resulting from pregnancy. METHODS: We combined information on pregnancy deaths from the National Vital Statistics System and the Pregnancy Mortality Surveillance System to estimate maternal (during or within 42 days of pregnancy) and pregnancy-related (during or within 1 year of pregnancy) mortality ratios (deaths per 100,000 live births). Data for 1995–1997, 1999–2002, and 2003–2005 were compared in order to estimate the effects of the change to ICD-10 and the inclusion of a pregnancy checkbox on the death certificate. RESULTS: The maternal mortality ratio increased significantly from 11.6 in 1995–1997 to 13.1 for 1999–2002 and 15.3 in 2003–2005; the pregnancy-related mortality ratio increased significantly from 12.6 to 14.7 and 18.1 during the same periods. Vital statistics identified significantly more indirect maternal deaths in 2002–2005 than in 1999–2002. Between 2002 and 2005, mortality ratios increased significantly among 19 states using the revised death certificate with a pregnancy checkbox; ratios did not increase in states without a checkbox. CONCLUSION: Changes in ICD-10 and the 2003 revision of the death certificate increased ascertainment of pregnancy deaths. The changes may also have contributed to misclassification of some deaths as maternal in the vital statistics system. Combining data from both systems estimates higher pregnancy mortality ratios than from either system individually. LEVEL OF EVIDENCE: II

Pregnancy-related mortality in Hispanic women in the United States

OBJECTIVE To examine pregnancy-related mortality among Hispanic women in the United States. METHODS We used data from the Centers for Disease Control and Preventions ongoing Pregnancy Mortality Surveillance System to examine all reported pregnancy-related deaths (deaths during or within 1 year of pregnancy that were caused by pregnancy, its complications, or treatment) in states that reported Hispanic origin for 1979-1992. The pregnancy-related mortality ratio was defined as the number of pregnancy-related deaths per 100,000 live births. RESULTS For the 14-year period, the overall pregnancy-related mortality ratio was 10.3 deaths per 100,000 live births for Hispanic women, 6.0 for non-Hispanic white women, and 25.1 for black women. In Hispanic subgroups, the pregnancy-related mortality ratio was 9.7 for Mexican women and ranged from 7.8 for Cuban women to 13.4 for Puerto Rican women. Pregnancy-induced hypertension was the leading cause of pregnancy-related death for Hispanic women overall. CONCLUSION Pregnancy-related mortality ratios for Hispanic women were higher than those for non-Hispanic white women, but markedly lower than those for black women. The similarity in socioeconomic status between Hispanic and black women was not an indicator of similar health outcomes. Prevention of pregnancy-related deaths in Hispanic women should include investigation of medical and nonmedical factors and consider the heterogeneity of the Hispanic population.

Pregnancy-related mortality among women with multifetal pregnancies

OBJECTIVE To examine the relative risk of pregnancy-related mortality between multifetal pregnancies and singleton pregnancies. METHODS We used data from the Centers for Disease Control and Preventions Pregnancy Mortality Surveillance System to examine singleton and multifetal pregnancy-related deaths among women with a live birth or fetal death from 1979-2000. The plurality-specific (singleton or multifetal) pregnancy-based mortality ratio was defined as the number of pregnancy-related deaths per 100,000 pregnancies with a live birth. We analyzed the risk of death due to pregnancy for singleton and multifetal pregnancies by age, race, education, marital status, and cause of death. RESULTS Of 4,992 pregnancy-related deaths in 1979-2000, 4.2% (209 deaths) were among women with multifetal pregnancies. The risk of pregnancy death among women with twin and higher-order pregnancies was 3.6 times that of women with singleton pregnancies (20.8 compared with 5.8). The leading causes of death were similar for women with singleton pregnancies and women with multifetal pregnancies: embolism, hypertensive complications of pregnancy, hemorrhage, and infection. CONCLUSION Women with multifetal pregnancies have a significantly higher risk of pregnancy-related death than their counterparts with singleton pregnancies; this holds true for all women regardless of age, race, marital status, and level of education. LEVEL OF EVIDENCE II-2.