Washington - High rates of obesity, high blood pressure and inadequate prenatal care cause death from childbirth more often for African-Americans in the United States than for whites and other ethnic groups.
Worsening this trend are the increasing numbers of cesarean sections nationally. These procedures can result in deadly complications for women dangerously overweight or suffering from hypertension or other ailments.
Nationally, blacks have a four-times greater risk of pregnancy-related death than whites - a rate of 36.1 per 100,000 live births compared with 9.6 for whites and 8.5 for Hispanics, according to a 2008 report by the Centers for Disease Control and Prevention (CDC).
Maternal mortality rates have been rising in the United States since the mid-1990s. In 1997, the black maternal mortality rate was 21.5 per 100,000 live births compared with 8.0 for Hispanics and 5.2 for whites, according to the CDC. The rate for other races was 8.8.
By 2007, the black maternal mortality rate had jumped to 28.4, roughly three times the rates among whites and Hispanics at 10.5 and 8.9 respectively. Statistics were not broken out for Asians/Pacific Islanders and Native Americans.
Trends show that black maternal mortality rates are increasing in some parts of the country, and two recent studies highlighting the problem have renewed calls for increased focus on reducing the deaths.
According to the new reports, the pregnancy-related mortality rate in some states rivals that in some developing nations. The problem is particularly acute in New York City, where blacks are nearly eight times more likely to die from pregnancy-related complications than whites, and in California where pregnant blacks are four times as likely to die from childbirth.
"The magnitude of this black-white gap in maternal mortality is the greatest among all health disparities . . . and that gap is growing. It's unacceptable," Michael Lu, an associate professor of obstetrics and gynecology and public health at UCLA and an expert in racial and socio-economic disparities in maternal and infant health, recently told PBS NewsHour.
The black-white gap also stubbornly persists for a variety of socio-economic reasons, including education and income levels, access to and quality of health care, and lifestyle and diet. Improved health care could reduce the maternal death rate by 40 percent to 50 percent, according to CDC estimates, but medical attention has been focused more often on reducing infant mortality during the past decades.
"When we look at some of the factors associated with maternal mortality, most of the underlying factors tend to be dominant in the African-American community, and it is manifested in the health disparities that affect our population," says Dr. Kerry M. Lewis, chairman of the Department of Obstetrics and Gynecology at Howard University's College of Medicine and chief of the Division of Maternal-Fetal Medicine.
Lewis, who specializes in high-risk pregnancies, says the mortality rate reflects lack of access to specialized health care that integrates comprehensive skills and technology. Too often, he says, patients are treated by family practitioners, nurse midwives, general obstetricians and gynecologists instead of specialists trained in high-risk pregnancies and medical problems that can cause complications during birth.
Obesity and hypertension are the major contributors to the black maternal mortality rate, leading to death from strokes, renal failure and other complications associated with obesity, Lewis says.
"We have to look at the reality of where we practice," he says. "Obesity is much greater among African-Americans. I deal with a gamut of high-risk problems, but complications from obesity are an underlying problem in all of them.
"Even young patients when they come in for prenatal visits have very elevated rates of high blood pressure. It really starts with obesity, so when they become pregnant, it places them at a higher risk for infections and other complications." To a lesser extent, sickle-cell disease, a genetic disorder more common in people of color, also causes complications, he says. Lewis, who also chairs the District of Columbia section of the American Congress of Obstetrics and Gynecology, says the increase in C-sections has compounded the problem because they can lead to hemorrhage, infections and pulmonary embolisms, or blood clots in the lungs. One-third of births in the United States are now by C-section compared with 20 percent a decade ago.
"Women who have C-sections have higher rates of complications and maternal mortality than with vaginal deliveries," Lewis says.
The California study bears this out. Of the 386 women who died in the state during childbirth in 2002 and 2003, it found, 65 had undergone C-sections "and most were unplanned or emergency surgeries to try and save the life of the mother or the infant." Additionally, more than one-third of the deaths "were determined to have had a good to strong chance of being prevented and some causes of death appeared to be more preventable than others."
The study also found that:
* Blacks in California had a four-times higher risk of maternal death and were more likely to have been overweight or obese and to have risk factors identified in the prenatal period.
* High rates of obesity or excessive gestational weight gain were contributing factors in one of four deaths.
* From 2006 to 2008, the black maternal mortality rate in the state was 46.1 deaths per 100,000 live births, compared with 12.8 for Hispanics, 12.4 for whites and 9.3 for Asians.
* Although blacks account for only 6 percent of California births, they represented 22 percent of pregnancy-related deaths in 2002 and 2003. Hispanics had the largest number of pregnancy-related deaths, 44 percent, and account for 51 percent of births statewide.
* Cardiomyopathy, or heart disease, was the leading cause of death for blacks with pregnancy-related deaths and accounted for 36 percent of the 22 deaths in that group and 62 percent of all deaths due to the disease.
* Thirty-one percent of mothers who died had not completed high school.
Conrad Chao, department chair and program director of obstetrics and gynecology at the University of California, San Francisco, who worked on the report, has said that he was surprised by "the magnitude of the disparity" and that the quality of care given these women needs further exploration.
The CDC issued a report in 2001 calling for comprehensive, broad-based public health surveillance of pregnancy-related deaths to identify factors, from pre-pregnancy through six weeks after birth, that affect a woman's chance of survival and that place minority and older women at increased risk of death. The report said surveillance must include reviewing the causes of deaths, analyzing the findings and coordinating action among public health agencies.
"Too often, surveillance stops after identifying and counting deaths," the report states. "With the resources available today, we should be able to eliminate this gap in such an important health outcome."