User Support

April 2009

C. Allison Russo, M.P.H, Lauren Wier, M.P.H., and Claudia Steiner, M.D., M.P.H.



Introduction

Hospitalizations related to childbirth comprise a large portion of U.S. hospital care. In 2006, the delivery of infants was the most common reason for hospitalization in U.S. community hospitals. During a woman’s hospital stay for childbirth, a variety of procedures may be performed. Over the last decade, there has been a dramatic shift in the utilization of certain obstetric procedures, in part due to increases in medically elective Cesarean sections (C-sections).¹ Moreover, vaginal births after C-section (VBAC), which are associated with rare but serious complications including uterine scar rupture², have also declined in recent years and further contribute to the growing number of repeat C-sections performed.

These changes in the use of certain childbirth-related procedures have garnered media attention and stimulated interest in research on the safety, clinical outcomes, and economic implications of shifts in mode of delivery and utilization of obstetric procedures. While some studies have highlighted the maternal benefits of elective C-sections³, other research indicates that C-sections generally tend to be more costly than vaginal deliveries⁴ and are associated with higher rates of maternal rehospitalization and postpartum medical care utilization.^5,6 Additionally, while the present brief focuses on the maternal impact, some research indicates potentially worse neonatal outcomes for C-section deliveries, including elevated risk of mortality.⁷ In light of the importance of childbirth-related hospitalizations in the healthcare system, it is important to better quantify and understand the impact of changing trends in hospital procedures for childbirth.

This Statistical Brief presents data from the Healthcare Cost and Utilization Project (HCUP) on childbirths occurring in U.S. community hospitals in 2006. All data are reported from the maternal perspective (i.e., reflecting the experience of the mother, not the newborn). Variations in the utilization and costs associated with childbirth-related hospitalizations are illustrated with a focused look at differences across mode of delivery and payer type. All differences between estimates noted in the text are statistically significant at the 0.05 level or better.

Findings

In 2006, women experienced 4.3 million childbirths in U.S. community hospitals, making the delivery of infants the most common reason for hospitalization. Childbirth-related hospitalizations totaled $14.8 billion in hospital costs.

Utilization characteristics of childbirth-related hospitalizations
Table 1 presents utilization, length of stay (LOS), and cost information for maternal hospitalizations associated with the delivery of infants in U.S. community hospitals by mode of delivery. The mean LOS for all deliveries was 2.6 days and ranged considerably from 2.1 days for vaginal deliveries without complications to 4.4 days for C-sections with complications.

On average, hospital deliveries cost $3,500 per stay, but the mean cost per stay was highly variable depending on the mode of delivery. C-sections tended to be more costly than vaginal deliveries ($4,500 versus $2,600 without complications, and $6,100 versus $3,500 with complications, respectively). However, vaginal delivery with an operating room procedure had the highest average cost ($6,900)—nearly double the cost per stay for all types of delivery ($3,500). In total, vaginal deliveries accounted for 55 percent of annual hospital delivery costs ($8.2 billion), and C-sections accounted for the remaining 45 percent ($6.6 billion).

Utilization differences by payer
Table 2 displays the number of hospital stays, average LOS, and cost information for maternal hospitalizations associated with the delivery of infants by expected primary payer. Half of all maternal childbirth-related hospital stays were billed to private insurance ($7.5 billion), while 42 percent were billed to Medicaid ($6.3 billion). The remaining 8 percent was billed to uninsured individuals, "other" insurance plans, or Medicare.⁸ The duration and average cost were similar across all payer groups (LOS range 2.4-2.7 days; cost per stay range $3,400-$3,500), with the exception of Medicare, which averaged longer stays (3.1 days) and higher costs per stay ($4,100).

Procedures commonly associated with childbirth-related hospitalizations
In 2006, the most common procedures performed in U.S. hospitals among females were related to childbirth and included those that assisted with the delivery of infants and C-sections, representing more than 3 million procedures combined. Table 3 lists the procedures commonly associated with hospital stays for childbirth. More than half of childbirth-related hospitalizations involved medical induction, manually assisted delivery, and other procedures to assist delivery. The second and third most common procedures overall were repair of current obstetric laceration and C-section, which were performed in 32.2 percent and 31.6 percent of childbirth-related hospitalizations, respectively. In fact, C-sections were, overall, the most commonly performed operating room procedures in U.S. hospitals in 2006. Other frequent procedures included artificial rupture of membranes to assist delivery (performed in 23.7 percent of all childbirths) and fetal monitoring (performed in 22.5 percent of all childbirths).

Utilization of specific obstetrical procedures: C-sections, vaginal birth after C-section (VBAC), episiotomies, and use of forceps
Of the 4.3 million childbirths that occurred in U.S. hospitals in 2006, nearly a third of cases (31.6 percent) were delivered via C-section—a 51 percent increase from 1997, when about a fifth of deliveries were performed via C-section (figure 1). However, as shown in figure 2, the rate of C-sections varied by payer.

Private insurance had the highest percentage of C-sections (33.7 percent), while uninsured individuals had the lowest percentage (25.4 percent). C-sections accounted for 29.8 percent of childbirth-related hospitalizations billed to Medicaid.

Vaginal birth after C-section (VBAC) is the delivery of a newborn vaginally by a woman who has previously given birth via C-section. Figure 3 illustrates the changes in rates of VBACs compared with repeat C-sections from 1997 to 2006. In 2006, only 9.7 percent of childbirth-related hospitalizations among females with a previous C-section were VBACs, as compared with 35.3 percent in 1997—a 73 percent decline. In contrast, there was a 40 percent rise in the rate of repeat C-sections among females with a previous C-section, from 64.7 percent in 1997 to 90.3 percent in 2006.

Because of changing practice patterns⁹ and fewer vaginal births, the past decade has also seen a decline in certain procedures associated with vaginal births, such as episiotomies and use of forceps (figure 4). Episiotomy is a surgical incision made into the perineum—the region between the vagina and the anus—to widen the vaginal opening for delivery. Forceps are used to aid in the delivery of the fetus by applying traction to the fetal head. From 1996 to 2006, the use of forceps decreased by 37 percent, and there were 55 percent fewer episiotomies.

Data Source

The estimates in this Statistical Brief are based upon data from the HCUP 2006 Nationwide Inpatient Sample (NIS). Historical data were drawn from the 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, and 2005 NIS.

Definitions

Procedures, ICD-9-CM, Clinical Classifications Software (CCS), and Diagnosis-Related Groups (DRGs)
The principal procedure is the procedure that was performed for definitive treatment rather than one performed for diagnostic or exploratory purposes (i.e., the procedure that was necessary to take care of a complication). If two procedures appear to meet this definition, the procedure most related to the principal diagnosis was selected as the principal procedure. All-listed procedures include all procedures performed during the hospital stay.

ICD-9-CM is the International Classification of Diseases, Ninth Revision, Clinical Modification, which assigns numeric codes to diagnoses and procedures. There are about 13,600 ICD-9-CM diagnosis codes and 3,500 ICD-9-CM procedure codes.

CCS categorizes ICD-9-CM procedure codes into a manageable number of clinically meaningful categories.¹⁰ This "clinical grouper" makes it easier to quickly understand patterns of procedure use.

DRGs comprise a patient classification system that categorizes patients into groups that are clinically coherent and homogeneous with respect to resource use. DRGs group patients according to diagnosis, type of treatment (procedures), age, and other relevant criteria. Each hospital stay has one DRG assigned to it.

Case Definition
For this report, the following codes were used to identify childbirth-related diagnoses and procedures:

Types of hospitals included in HCUP
HCUP is based on data from community hospitals, defined as short-term, non-Federal, general and other hospitals, excluding hospital units of other institutions (e.g., prisons). HCUP data include OB-GYN, ENT, orthopedic, cancer, pediatric, public, and academic medical hospitals. They exclude long-term care, rehabilitation, psychiatric, and alcoholism and chemical dependency hospitals, but these types of discharges are included if they are from community hospitals.

Unit of analysis
The unit of analysis is the hospital discharge (i.e., the hospital stay), not a person or patient. This means that a person who is admitted to the hospital multiple times in one year will be counted each time as a separate "discharge" from the hospital.

Costs and charges
Total hospital charges were converted to costs using HCUP Cost-to-Charge Ratios based on hospital accounting reports from the Centers for Medicare and Medicaid Services (CMS).11 Costs will tend to reflect the actual costs of production, while charges represent what the hospital billed for the case. For each hospital, a hospital-wide cost-to-charge ratio is used because detailed charges are not available across all HCUP States. Hospital charges reflect the amount the hospital charged for the entire hospital stay and does not include professional (physician) fees. For the purposes of this Statistical Brief, costs are reported to the nearest hundred.

Payer
Payer is the expected primary payer for the hospital stay. To make coding uniform across all HCUP data sources, payer combines detailed categories into more general groups:
When more than one payer is listed for a hospital discharge, the first-listed payer is used.

About HCUP

HCUP is a family of powerful healthcare databases, software tools, and products for advancing research. Sponsored by the Agency for Healthcare Research and Quality (AHRQ), HCUP includes the largest all-payer encounter-level collection of longitudinal healthcare data (inpatient, ambulatory surgery, and emergency department) in the United States, beginning in 1988. HCUP is a Federal-State-Industry Partnership that brings together the data collection efforts of many organizations——such as State data organizations, hospital associations, private data organizations, and the Federal government—to create a national information resource.

HCUP would not be possible without the contributions of the following data collection Partners from across the United States:

Arizona Department of Health Services
Arkansas Department of Health
California Office of Statewide Health Planning & Development
Colorado Hospital Association
Connecticut Hospital Association
Florida Agency for Health Care Administration
Georgia Hospital Association
Hawaii Health Information Corporation
Illinois Department of Public Health
Indiana Health Association
Iowa Hospital Association
Kansas Hospital Association
Kentucky Cabinet for Health and Family Services
Maine Health Data Organization
Maryland Health Services Cost Review Commission
Massachusetts Division of Health Care Finance and Policy
Michigan Health & Hospital Association
Minnesota Hospital Association
Missouri Hospital Industry Data Institute
Nebraska Hospital Association
Nevada Department of Health and Human Services
New Hampshire Department of Health & Human Services
New Jersey Department of Health and Senior Services
New York State Department of Health
North Carolina Department of Health and Human Services
Ohio Hospital Association
Oklahoma State Department of Health
Oregon Association of Hospitals and Health Systems
Rhode Island Department of Health
South Carolina State Budget & Control Board
South Dakota Association of Healthcare Organizations
Tennessee Hospital Association
Texas Department of State Health Services
Utah Department of Health
Vermont Association of Hospitals and Health Systems
Virginia Health Information
Washington State Department of Health
West Virginia Health Care Authority
Wisconsin Department of Health and Family Services

About the NIS

The HCUP Nationwide Inpatient Sample (NIS) is a nationwide database of hospital inpatient stays. The NIS is nationally representative of all community hospitals (i.e., short-term, non-Federal, non-rehabilitation hospitals). The NIS is a sample of hospitals and includes all patients from each hospital, regardless of payer. It is drawn from a sampling frame that contains hospitals comprising about 90 percent of all discharges in the United States. The vast size of the NIS allows the study of topics at both the national and regional levels for specific subgroups of patients. In addition, NIS data are standardized across years to facilitate ease of use.

For More Information

For more information about HCUP, visit http://www.hcup-us.ahrq.gov/.

For additional HCUP statistics, visit HCUPnet, our interactive query system, at www.hcup-us.ahrq.gov.

For information on other hospitalizations in the U.S., download HCUP Facts and Figures: Statistics on Hospital-based Care in the United States in 2006, located at http://www.hcup-us.ahrq.gov/reports.jsp.

For a detailed description of HCUP, more information on the design of the NIS, and methods to calculate estimates, please refer to the following publications:

Steiner, C., Elixhauser, A., Schnaier, J. The Healthcare Cost and Utilization Project: An Overview. Effective Clinical Practice 5(3):143–51, 2002.

Introduction to the HCUP Nationwide Inpatient Sample, 2006. Online. May 14, 2008. U.S. Agency for Healthcare Research and Quality. http://www.hcup-us.ahrq.gov/db/nation/nis/2006NIS_INTRODUCTION.pdf.

Houchens, R., Elixhauser, A. Final Report on Calculating Nationwide Inpatient Sample (NIS) Variances, 2001.. HCUP Methods Series Report #2003-2. Online. June 2005 (revised June 6, 2005). U.S. Agency for Healthcare Research and Quality. http://www.hcup-us.ahrq.gov/reports/methods/2003_02.pdf .

Houchens R.L., Elixhauser A. Using the HCUP Nationwide Inpatient Sample to Estimate Trends. (Updated for 1988–2004). HCUP Methods Series Report #2006-05. Online. August 18, 2006. U.S. Agency for Healthcare Research and Quality. http://www.hcup-us.ahrq.gov/reports/methods/2006_05_NISTrendsReport_1988-2004.pdf

Suggested Citation

Russo, C.A. (Thomson Reuters), Wier, L. (Thomson Reuters) and Steiner, C. (AHRQ). Hospitalizations Related to Childbirth, 2006. HCUP Statistical Brief #71. April 2009. U.S. Agency for Healthcare Research and Quality, Rockville, MD. http://www.hcup-us.ahrq.gov/reports/statbriefs/sb71.pdf.

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AHRQ welcomes questions and comments from readers of this publication who are interested in obtaining more information about access, cost, use, financing, and quality of healthcare in the United States. We also invite you to tell us how you are using this Statistical Brief and other HCUP data and tools, and to share suggestions on how HCUP products might be enhanced to further meet your needs. Please e-mail us at hcup@ahrq.gov or send a letter to the address below:

Irene Fraser, Ph.D., Director
Center for Delivery, Organization, and Markets
Agency for Healthcare Research and Quality
540 Gaither Road
Rockville, MD 20850



¹ Macdorman MF, Menacker F, Declercq E. Cesarean birth in the United States: epidemiology, trends, and outcomes. Clinical Perinatology, 2008; 35:293-307.
² Guise J, Berlin M, McDonagh M, Osterweil P, Chan B, Helfand M. Safety of vaginal birth after Cesarean: A systematic review. American College of Obstetricians and Gynecologists, 2004; 103(3):420-29.
³ National Institutes of Health. State-of-the-Science Conference Statement. Cesarean delivery on maternal request. Obstetrics and Gynecology, 2006; 107: 1386–97.
⁴ Zupancic JAF. The economics of elective Cesarean section. Clinical Perinatology, 2008; 35:591-99.
⁵ Lui T, Chen C, Lin H. Does elective Cesarean section increase utilization of postpartum maternal medical care? Medical Care, 2008; 46(4):440-43.
⁶ Declercq E, Barger M, Cabral HJ, Evans SR, Kotelchuck M, Simon C, Weiss J, Heffner LJ. Maternal outcomes associated with planned primary Cesarean section births compared with planned vaginal births. Obstetrics and Gynecology, 2007; 109(3):669-77.
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⁸ Medicare provides health insurance for a limited number of individuals under the age of 65
⁹ Recent practice guidelines from the American College of Obstetrics and Gynecology (ACOG) suggest that the best available data do not support the liberal or routine use of episiotomy (Practice Bulletin #71, April 2006).
¹⁰ HCUP CCS. Healthcare Cost and Utilization Project (HCUP). August 2006. U.S. Agency for Healthcare Research and Quality, Rockville, MD. www.hcup-us.ahrq.gov/toolssoftware/ccs/ccs.jsp.
¹¹ HCUP Cost-to-Charge Ratio Files (CCR). Healthcare Cost and Utilization Project (HCUP). 2001–2005. U.S. Agency for Healthcare Research and Quality, Rockville, MD. www.hcup-us.ahrq.gov/db/state/costtocharge.jsp.