Perioperative Medicine  |   April 2018
Effect of Maternal Body Mass Index on Postpartum Hemorrhage
Author Notes
  • From the Department of Anesthesiology, Perioperative, and Pain Medicine (A.J.B., P.F.), the Division of Neonatal and Developmental Medicine (H.C.L.), the Department of Obstetrics and Gynecology (Y.Y.E-S.), Stanford University School of Medicine, Stanford, California; the California Maternal Quality Care Collaborative, Medical School Office Building, Stanford, California (A.A.); the Department of Anesthesiology, Brigham and Women’s Hospital/Harvard Medical School, Boston, Massachusetts (B.T.B.); the Department of Medicine Solna, Clinical Epidemiology Unit, and the Department of Women’s and Children’s Health, Karolinska Institutet, Stockholm, Sweden (O.S.).
  • This article was presented at the best research paper session at the 49th annual meeting of the Society for Obstetric Anesthesia and Perinatology, Seattle, Washington, May 12, 2017.
    This article was presented at the best research paper session at the 49th annual meeting of the Society for Obstetric Anesthesia and Perinatology, Seattle, Washington, May 12, 2017.×
  • Submitted for publication August 1, 2017. Accepted for publication December 12, 2017.
    Submitted for publication August 1, 2017. Accepted for publication December 12, 2017.×
  • Address correspondence to Dr. Butwick: Department of Anesthesiology, Perioperative, and Pain Medicine, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, California 94305. ajbut@stanford.edu. Information on purchasing reprints may be found at www.anesthesiology.org or on the masthead page at the beginning of this issue. Anesthesiology’s articles are made freely accessible to all readers, for personal use only, 6 months from the cover date of the issue.
Article Information
Perioperative Medicine / Clinical Science / Obstetric Anesthesia
Perioperative Medicine   |   April 2018
Effect of Maternal Body Mass Index on Postpartum Hemorrhage
Anesthesiology 4 2018, Vol.128, 774-783. doi:10.1097/ALN.0000000000002082
Anesthesiology 4 2018, Vol.128, 774-783. doi:10.1097/ALN.0000000000002082
Abstract

Background: It is unclear whether obesity is a risk factor for postpartum hemorrhage. The authors hypothesized that obese women are at greater risk of hemorrhage than women with a normal body mass index.

Methods: The authors conducted a cohort study of women who underwent delivery hospitalization in California between 2008 and 2012. Using multilevel regression, the authors examined the relationships between body mass index with hemorrhage (primary outcome), atonic hemorrhage, and severe hemorrhage (secondary outcomes). Stratified analyses were performed according to delivery mode.

Results: The absolute event rate for hemorrhage was 60,604/2,176,673 (2.8%). In this cohort, 4% of women were underweight, 49.1% of women were normal body mass index, 25.9% of women were overweight, and 12.7%, 5.2%, and 3.1% of women were in obesity class I, II, and III, respectively. Compared to normal body mass index women, the odds of hemorrhage and atonic hemorrhage were modestly increased for overweight women (hemorrhage: adjusted odds ratio [aOR], 1.06; 99% CI, 1.04 to 1.08; atonic hemorrhage: aOR, 1.07; 99% CI, 1.05 to 1.09) and obesity class I (hemorrhage: aOR, 1.08; 99% CI, 1.05 to 1.11; atonic hemorrhage; aOR, 1.11; 99% CI, 1.08 to 1.15). After vaginal delivery, overweight and obese women had up to 19% increased odds of hemorrhage or atonic hemorrhage; whereas, after cesarean delivery, women in any obesity class had up to 14% decreased odds of severe hemorrhage.

Conclusions: The authors’ findings suggest that, at most, maternal obesity has a modest effect on hemorrhage risk. The direction of the association between hemorrhage and body mass index may differ by delivery mode.