Research
Obstetrics
Trends in cesarean delivery at preterm gestation and association with perinatal mortality

Presented, in part, at the 30th Annual Meeting of the Society for Maternal-Fetal Medicine, Chicago, IL, Feb. 1-6, 2010.
https://doi.org/10.1016/j.ajog.2011.01.062Get rights and content

Objective

We sought to examine the extent to which a temporal increase in preterm cesarean delivery is associated with gestational age–specific changes in perinatal survival in preterm gestations.

Study Design

We utilized data on singleton births in the United States (1990 through 2004) delivered between 24-36 weeks' gestation. Associations between changes in cesarean delivery at preterm gestations and trends in the risk of preterm stillbirth, and neonatal and perinatal mortality were estimated before and after adjustments for a variety of potential confounders.

Results

From 1990 through 2004, cesarean delivery rates increased by 50.6%, 40.7%, and 35.8% at 24-27, 28-33, and 34-36 weeks, respectively. The largest incremental effect of cesarean was associated with a reduction in stillbirths by 5.8%, 14.2%, and 23.1% at 24-27, 28-33, and 34-36 weeks, respectively, leading to an 11.4%, 4.9%, and 0.6% reduction in perinatal deaths at 24-27, 28-33, and 34-36 weeks, respectively.

Conclusion

Increasing rates of preterm cesarean were associated with improved perinatal survival. This association was evident largely because of dramatic incremental declines in stillbirths.

Section snippets

Materials and Methods

We utilized the US-linked natality and infant deaths data files composed of births from 1990 through 2004, and the corresponding fetal death files for the same period. These data files correspond to data abstracted from birth certificates of live-born infants and from fetal and infant death certificates and assembled by the National Center for Health Statistics (NCHS) of the Centers for Disease Control and Prevention.17 Infant deaths from 1992 through 1994 were not linked to the corresponding

Temporal changes in preterm cesarean deliveries and perinatal mortality

Temporal trends in rates of preterm cesarean delivery from 1990 through 2004 and the corresponding relative changes in rates with 1990 as the base period are shown in Figure 1. Relative to the rates in 1990, preterm cesarean delivery increased by 37% (25.5% in 1990 to 35.0% in 2004). This increase in preterm cesarean was greatest at 24-27 weeks (Table 1). There was an overall 20.2% decline in preterm stillbirths from 1990 through 2004 (Figure 2); however, the greatest decline occurred at 34-36

Comment

This large population-based study of singleton preterm births in the United States shows that the steep temporal increase in preterm cesarean deliveries appears to be favorably associated with a concurrent decline in preterm stillbirth and early neonatal mortality. For instance, the increase in cesarean deliveries from 1990 through 2004 by 47.6% at 24-27 weeks, 31.7% at 28-33 weeks, and 28.9% at 34-36 weeks was associated with an 11.4%, 4.9%, and 0.6% decline in perinatal mortality rates at

References (33)

  • F. Menacker

    Trends in cesarean rates for first births and repeat cesarean rates for low-risk women: United States, 1990-2003

    Natl Vital Stat Rep

    (2005)
  • M.F. MacDorman et al.

    Infant and neonatal mortality for primary cesarean and vaginal births to women with ”no indicated risk,” United States, 1998-2001 birth cohorts

    Birth

    (2006)
  • P.K. Muhuri et al.

    Method of delivery and neonatal mortality among very low birth weight infants in the United States

    Matern Child Health J

    (2006)
  • S.L. Boulet et al.

    Secular trends in cesarean delivery rates among macrosomic deliveries in the United States, 1989 to 2002

    J Perinatol

    (2005)
  • G.C. Smith et al.

    Mode of delivery and the risk of delivery-related perinatal death among twins at term: a retrospective cohort study of 8073 births

    BJOG

    (2005)
  • K.D. Gregory et al.

    Changes in indications for cesarean delivery: United States, 1985 and 1994

    Am J Public Health

    (1998)
  • Cited by (0)

    Cite this article as: Ananth CV, Vintzileos AM. Trends in cesarean delivery at preterm gestation and association with perinatal mortality. Am J Obstet Gynecol 2011;204:505.e1-8.

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