Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2010 Nov;100(11):2241-7.
doi: 10.2105/AJPH.2009.180570. Epub 2010 Sep 23.

Obstetrical intervention and the singleton preterm birth rate in the United States from 1991-2006

Marian F MacDorman  1 , Eugene Declercq, Jun Zhang
Affiliations

Obstetrical intervention and the singleton preterm birth rate in the United States from 1991-2006

Marian F MacDorman et al. Am J Public Health. 2010 Nov.

Abstract

Objectives: We examined the relationship between obstetrical intervention and preterm birth in the United States between 1991 and 2006.

Methods: We assessed changes in preterm birth, cesarean delivery, labor induction, and associated risks. Logistic regression modeled the odds of preterm obstetrical intervention after risk adjustment.

Results: From 1991 to 2006, the percentage of singleton preterm births increased 13%. The cesarean delivery rate for singleton preterm births increased 47%, and the rate of induced labor doubled. In 2006, 51% of singleton preterm births were spontaneous vaginal deliveries, compared with 69% in 1991. After adjustment for demographic and medical risks, the mother of a preterm infant was 88% (95% confidence interval [CI] = 1.87, 1.90) more likely to have an obstetrical intervention in 2006 than in 1991. Using new birth certificate data from 19 states, we estimated that 42% of singleton preterm infants were delivered via induction or cesarean birth without spontaneous onset of labor.

Conclusions: Obstetrical interventions were related to the increase in the US preterm birth rate between 1991 and 2006. The public health community can play a central role in reducing medically unnecessary interventions.

PubMed Disclaimer

Figures

FIGURE 1
FIGURE 1
Percentages of singleton births, by method of delivery, for (a) preterm births (less than 37 weeks), (b) late preterm births (34–36 weeks), and (c) early preterm births (less than 34 weeks): United States, 1991–2006. Note. Births lacking information on method of delivery and whether labor was induced are excluded.
FIGURE 2
FIGURE 2
Estimate of the percentage of singleton preterm births in which obstetrical intervention affected gestational age at delivery: 19 US states, 2006. aStates using the 2003 revision of the US standard birth certificate. bBirths lacking data on method of delivery, whether or not labor was induced, and whether or not a trial of labor was attempted are excluded. cInduction of labor (attempted or successful). dNo reported precipitous, prolonged, or augmented labor; fetal intolerance of labor; or use of forceps or vacuum.
See this image and copyright information in PMC

References

    1. Martin JA, Hamilton BE, Sutton PD, et al. Births: final data for 2006. Natl Vital Stat Rep. January 7, 2009;57(7).
    1. National Center for Health Statistics Advance report of maternal and infant health data from the birth certificate, 1991. Month Vital Stat Rep. May 11, 1994;42(suppl 11).
    1. Menacker F. Trends in cesarean rates for first births and repeat cesarean rates for low-risk women: United States, 1990–2003. Natl Vital Stat Rep. September 22, 2005;54(4). - PubMed
    1. Declercq E, Menacker F, MacDorman MF. Maternal risk profiles and the primary cesarean rate in the United States, 1991–2002. Am J Public Health. 2006;96(5):867–872 - PMC - PubMed
    1. Bailit JL, Love TE, Mercer B. Rising cesarean rates: are patients sicker? Am J Obstet Gynecol. 2004;191(3):800–803 - PubMed