Although delivery related complications are rare among vaginal VD and cesarean CD deliveries, the 4

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Improvements in US maternal obstetrical outcomes
from 1992 to 2006
Sindhu K. Srinivas, MD1, Andrea G. Edlow, MD1,
Jamie Bastek, MD1, Christina M. Andrela, BSN1,
Michal A. Elovitz, MD1
Sindhu K. Srinivas, MD, MSCE1,2, Andrew J.
Epstein, PhD3, Sean Nicholson, PhD4, Jeph Herrin,
PhD3, David A. Asch, MD, MBA2,5
Department of Obstetrics and Gynecology, Division
of Maternal Fetal Medicine, Center for Research
on Reproduction and Womens Health, University of
Pennsylvania, Philadelphia, PA1
1Department of OB/GYN, CRRWH, University of
Pennsylvania, 2Leonard Davis Institute of Health
Economics, University of Pennsylvania, 3Yale
University, 4Cornell University, 5Center for
Health Equity Research and Promotion,
Philadelphia VA Medical Center
ABSTRACT
OBJECTIVE

• We used logistic regression to calculate
  complication rates adjusting for differences in
  35 maternal comorbidities, including fetal
  malpresentation, prior cesarean delivery, severe
  hypertension, multiple gestation, antepartum
  bleeding, herpes, macrosomia, unengaged head,
  maternal soft tissue disorder, preterm labor,
  congenital anomalies, oligohydramnios, and
  polyhydramnios.
• To confirm trends observed in New York and
  Florida, we repeated these analyses using the
  Nationwide Inpatient Sample (NIS) from 1997
  through 2006.

• We examined trends in all obstetric procedures
  and maternal outcomes in two states (NY and FL)
  from 1992 to 2006.

Objective Changing quality of care should be
reflected in changing outcomes over time. We
examined 15-year trends in risk-adjusted maternal
complications following childbirth. Methods
Using Florida and New York hospital discharge
data from 1992-2006, we examined maternal
obstetrical outcomes among over 6 million women
undergoing cesarean delivery (CD) and vaginal
delivery (VD). Obstetric procedures and
individual and composite maternal post delivery
complications including infection, hemorrhage,
laceration, and other major operative and
thrombotic complications were evaluated. Results
During the 15-year time period, the CD rate
decreased from 24.7 in 1992 to 23 in 1996 and
increased to 34.7 in 2006. The risk-adjusted
rate of any major complication declined from
14.7 in 1992 to 10.7 in 2006 for all
deliveries from 14.4 to 11.6 for VD and from
15.7 to 8.5 for CD. During 1992 to 2006, the
average number of comorbidities increased from
0.65 to 0.93 for patients overall, from 0.43 to
0.58 for VD patients, and 1.34 to 1.59 for CD
patients. Conclusion As evidenced by New York
and Florida, the US has seen large reductions in
major maternal complications over the past 15
years. Concurrently, the average number of
comorbidities increased. These results may
reflect improvements in US maternal care over the
study period.

METHODS
RESULTS

• We examined Florida and New York hospital
  discharge data from 1992 to 2006 representing
  every delivery at all non-federal acute care
  hospitals in these states.
• Obstetric procedures were identified using
  International Classification of Disease, 9th
  edition, Clinical Modification (ICD-9) codes.
• CD were stratified into labor or non-labor, and
  prior cesarean delivery or primary cesarean
  delivery for analysis.
• Maternal complication rates of infection,
  hemorrhage, severe laceration, and other major
  operative and thrombotic complications were
  calculated individually and as a composite
  (COMP).
• COMP for VDdichotomous variable including
  hemorrhage, severe laceration, infection and
  thrombotic complications.
• COMP for CD dichotomous variable including
  infection, hemorrhage, and other major operative
  and thrombotic complications.

• Over 6 million deliveries (N6,666,225) were
  included.
• CD decreased from 24.7 in 1992 to 23.0 in 1996
  and increased to 34.7 in 2006.
• VD increased from 75.3 in 1992 to 76.9 in 1996
  and then decreased to 65.3 in 2006.
• Episiotomy declined from 51.7 in 1992 to 18.3
  in 2006.
• Forceps declined from 6.3 to 1.7.
• Vacuum increased from 5.6 in 1992 to 6.8 in
  1996, and declined to 5.5 in 1999 and stayed
  constant through 2006.
• Overall Risk-adjusted rate for COMP declined from
  14.7 in 1992 to 10.7 in 2006.
• VD COMP rates declined from 14.4 to 11.6.
• CD COMP rates declined from 15.7 in 1992 to 8.5
  in 2001 and remained constant through 2006.
• Infection rates declined from 6.6 to 2.2.
• Laceration rates declined from 6.9to 5.
• Among VDs, hemorrhage rates decreased from 4.7
  to 3.6.
• Among CDs, hemorrhage rates decreased from 7.7
  in 1992 to 3.8 in 2001 and subsequently
  increased to 4.9 in 2006.

• Average number of comorbidities increased from
  0.65 to 0.93 for patients overall.
• Similar trends were observed among all delivery
  modes.
• Similar complication trends were observed when we
  examined deliveries from New York and Florida
  separately, and when we examined the NIS sample.

CONCLUSIONS

• These results suggest that maternal obstetrical
  outcomes in US hospitals have improved
  substantially in the last 15 years.
• These trends in complication rates are not fully
  explained. They coincide with improving
  technology, declining use of forceps and
  episiotomy in vaginal deliveries, a decline in
  attempted or completed VBAC, and a more recent
  increase in primary cesarean delivery.
• Further research is needed to explore the rise
  in hemorrhage rate observed in CD since 2001.
• Our results reveal substantial and sustained
  population-level improvements in US maternal
  obstetrical outcomes, although they do not
  identify which particular elements of care
  explain those improvements. Nevertheless,
  maternal outcomes after childbirth are
  substantially better now than in 1992.

BACKGROUND

• Although delivery related complications are rare
  among vaginal (VD) and cesarean (CD) deliveries,
  the 4 million US births each year amplifies the
  population health significance of even minor
  trends in maternal complications.
• Understanding trends in delivery related
  complications is important given the recent
  increase in cesarean deliveries and the potential
  for that change to alter maternal outcomes.