Perioperative Medicine  |   September 2018
Maternal Body Mass Index and Use of Labor Neuraxial Analgesia: A Population-based Retrospective Cohort Study
Author Notes
  • From the Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, California (A.J.B., N.G.); and the University of Iowa Carver College of Medicine, Iowa City, Iowa (C.A.W.).
  • Submitted for publication October 20, 2017. Accepted for publication May 14, 2018.
    Submitted for publication October 20, 2017. Accepted for publication May 14, 2018.×
  • Address correspondence to Dr. Butwick: Department of Anesthesiology, Perioperative and Pain Medicine (MC:5640), 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   |   September 2018
Maternal Body Mass Index and Use of Labor Neuraxial Analgesia: A Population-based Retrospective Cohort Study
Anesthesiology 9 2018, Vol.129, 448-458. doi:10.1097/ALN.0000000000002322
Anesthesiology 9 2018, Vol.129, 448-458. doi:10.1097/ALN.0000000000002322
Abstract

What We Already Know about This Topic:

  • Neuraxial labor analgesia for parturients is often recommended to avoid airway instrumentation in case of urgent surgical delivery

  • The extent to which neuraxial use varies by maternal body mass index using modern, national data remains unknown

What This Article Tells Us That Is New:

  • Of 17 million women delivering at a U.S. hospital between 2009 and 2015, 68% of women with a normal body mass index received neuraxial analgesia, while 76% of women with a body mass index more than 40 kg/m2 received neuraxial analgesia

  • Only 60% of underweight parturients received neuraxial analgesia

Background: Neuraxial labor analgesia may benefit obese women by optimizing cardiorespiratory function and mitigating complications related to emergency general anesthesia. We hypothesized that obese women have a higher rate of neuraxial analgesia compared with nonobese parturients.

Methods: Using U.S. natality data, our cohort comprised 17,220,680 deliveries, which accounts for 61.5% of 28 million births in the United States between 2009 and 2015. We examined the relationships between body mass index class and neuraxial labor analgesia, adjusting for sociodemographic, antenatal, pregnancy, and peripartum factors.

Results: The study cohort comprised 17,220,680 women; 0.1% were underweight, 12.7% were normal body mass index, 37% were overweight, and 28.3%, 13.5%, and 8.4% were obesity class I, II, and III, respectively. Rates of neuraxial analgesia by body mass index class were as follows: underweight, 59.7% (9,030/15,128); normal body mass index, 68.1% (1,487,117/2,182,797); overweight, 70.3% (4,476,685/6,368,656); obesity class I, 71.8% (3,503,321/4,881,938); obesity class II, 73.4% (1,710,099/2,330,028); and obesity class III, 75.6% (1,089,668/1,442,133). Compared to women with normal body mass index, the likelihood of receiving neuraxial analgesia was slightly increased for overweight women (adjusted relative risk, 1.02; 95% CI, 1.02 to 1.02), obese class I (adjusted relative risk, 1.04; 95% CI, 1.04 to 1.04), obese class II (adjusted relative risk, 1.05; 95% CI, 1.05 to 1.05), and obese class III (adjusted relative risk, 1.06; 95% CI, 1.06 to 1.06).

Conclusions: Our findings suggest that the likelihood of receiving neuraxial analgesia is only marginally increased for morbidly obese women compared to women with normal body mass index.