Severe complications from childbirth are rare in the U.S., but they are becoming more common, a new government study finds.
Between 1998 and 2009, the rate of serious complications like heart attack, stroke, severe bleeding and kidney failure during or after childbirth roughly doubled among U.S. women, according to researchers at the Centers for Disease Control and Prevention (CDC).
In 2008-2009, there were 129 cases of severe complications for every 10,000 women who delivered in a hospital. That was up 75 percent from a decade earlier.
At the same time, complications during women’s post-delivery hospital stay also rose: There were 29 cases for every 10,000 women - up 114 percent from 10 years before.
Serious complications and deaths from childbirth are still uncommon in the U.S. Over four million women give birth each year, and this study found about 590,000 cases of severe complications over 11 years.
“We don’t want to send the message that pregnant women should be afraid,” said Dr. William M. Callaghan of the CDC, who led the study.
With this type of study, which used discharge records from U.S. hospitals, it’s not possible to tell why childbirth complications rose, Callaghan said.
But it’s “well-documented” from other research that more women are giving birth at older ages, are obese, or have certain health conditions like high blood pressure and diabetes, he added.
There are also more young women with serious conditions, like congenital heart defects, who are surviving and having children.
During the same study period, increases in the U.S. cesarean delivery rate and in the proportion of pregnant women with chronic conditions, postpartum hemorrhage, obesity, multiple births, and advanced maternal age have been documented. Against the backdrop of increases in numbers of women with high-risk conditions, a call for returning the “M” to maternal-fetal medicine has been made.2 Given this context, a more nuanced review of cases is needed to identify modifiable risks and develop best practices to deal with risks that might not be modifiable. Approximately 5,600 women died during a delivery or postpartum hospitalization during the period covered in this report. Although deaths are the most tragic events in obstetrics, our estimates suggest that severe maternal morbidity is on the order of 100 times more common. On an annual basis, with approximately 4,000,000 births in the United States, 129 episodes of severe maternal morbidity will affect approximately 52,000 women. Expanding the focus to what lies below the tip of the iceberg is needed, and we offer a comprehensive construct as a starting point for investigation. The information provided in this report has the potential to be used for clinical reviews, development of quality-of-care indicators, and identifying future research priorities in obstetrics.
The results of our study should be considered in light of the following limitations. First, although our identification of severe complications was based on an algorithm that uses ICD-9-CM codes and several data-driven criteria such as in-hospital mortality, transfer from or to another health care facility, and length of hospital stay, we were unable to fully assess the severity of these conditions. Hospital-based administrative databases that make up the Nationwide Inpatient Sample are primarily used for billing, and hence are subject to errors of omission and commission by medical coders as well as changes over time in coding practices. For example, we found that the average number of ICD-9-CM codes for all delivery and all postpartum hospitalizations increased from 3.6 and 2.9 to 4.6 and 4.5 between 1998–1999 and 2008–2009, respectively. However, the increasing number of postpartum hospitalizations in our study suggests that at least some increase in severe morbidity is the result of the increase in the number of hospitalizations with true morbidity rather than the result of the increase in the number of ICD-9-CM codes per admission. Moreover, administrative data do not provide details regarding sociodemographic or clinical obstetrical risk factors for severe maternal morbidity. Although identifying women according to the indications of severe complications may result in misclassification, the error likely will affect sensitivity rather than specificity as has been demonstrated in validation studies of hospital discharge data. However, the number of cases identified, especially at hospital and local levels, will be small and using medical records to review the clinical courses will serve to validate the proposed indicators and identify points of intervention for preventable complications.
In conclusion, we present an overview of trends in severe maternal morbidity, update previous reports, and propose a new standard for monitoring severe maternal morbidity that remains open to emerging issues in obstetrical care and management. Our findings suggest a substantial increase in severe complications for delivery and postpartum hospitalizations from 1998–1999 to 2008–2009, particularly as indicated by the growing rates for blood transfusions, acute renal failure, shock, acute myocardial infarction, respiratory distress syndrome, aneurysms, and cardiac surgery during delivery hospitalizations.
“The characteristics of the pregnant population are changing,” Callaghan said, so it’s not unexpected that rates of certain complications might rise.
Another recent CDC study found that minority women are at particular risk. Between 1993 and 2006, minority women accounted for 41 percent of all births nationwide, but 62 percent of all pregnancy-related deaths.
Black women were at greatest risk. For every 100,000 babies born to African Americans, 32 to 35 mothers died. That was roughly four times the rate among white mothers.
Heart problems were the most common cause of death. And in this latest study, Callaghan’s team found that one childbirth complication - the need for cardiac surgery during or after delivery - showed a “dramatic” rise over time.
It was still rare: In 2008-2009, just under 5 per 10,000 women needed a heart procedure during delivery, for example. But that was up 75 percent from a decade before.
Callaghan said the bottom line for women is to be as healthy as possible before pregnancy. Losing weight if you are obese, and getting high blood pressure and diabetes under control, are some ways to do that.
If you have existing medical conditions, like heart disease, it’s even more important to see your doctor before pregnancy, Callaghan said.
“Not all complications can be avoided, of course,” he said. “But the best outcomes happen when a woman is as healthy as possible going into pregnancy.”
He added that some women with pre-existing medical conditions may need to see an obstetrician who specializes in high-risk pregnancies.
“Most women do fine,” however, Callaghan said. “And even most women with significant disease before pregnancy do fine.”
SOURCE: Obstetrics & Gynecology, November 2012
Severe Maternal Morbidity Among Delivery and Postpartum Hospitalizations in the United States
RESULTS: Severe morbidity rates for delivery and postpartum hospitalizations for the 2008–2009 period were 129 and 29, respectively, for every 10,000 delivery hospitalizations. Compared with the 1998–1999 period, severe maternal morbidity increased by 75% and 114% for delivery and postpartum hospitalizations, respectively. We found increasing rates of blood transfusion, acute renal failure, shock, acute myocardial infarction, respiratory distress syndrome, aneurysms, and cardiac surgery during delivery hospitalizations. Moreover, during the study period, rates of postpartum hospitalization with 13 of the 25 severe complications examined more than doubled, and the overall mortality during postpartum hospitalizations increased by 66% (P
CONCLUSIONS: Severe maternal morbidity currently affects approximately 52,000 women during their delivery hospitalizations and, based on current trends, this burden is expected to increase. Clinical review of identified cases of severe maternal morbidity can provide an opportunity to identify points of intervention for quality improvement in maternal care.
Callaghan, William M. MD, MPH; Creanga, Andreea A. MD, PhD; Kuklina, Elena V. MD, PhD