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Meconium aspiration syndrome

Last reviewed: 23 Jun 2024
Last updated: 05 Apr 2024

Summary

Definition

History and exam

Key diagnostic factors

  • signs of postmaturity
  • tachypnea
  • cyanosis
  • chest wall asymmetry with decreased air entry
  • barrel-shaped chest
Full details

Other diagnostic factors

  • grunting
  • chest retractions
  • rales
  • rhonchi
  • tachycardia
  • hypotension
Full details

Risk factors

  • gestational age >42 weeks
  • pregnancy-induced hypertension
  • maternal diabetes mellitus
  • maternal smoking or substance misuse
  • fetal distress
  • oligohydramnios
  • thick meconium
  • Apgar score <7
  • chorioamnionitis
  • cesarean delivery
  • black ancestry
  • male sex
Full details

Diagnostic tests

1st tests to order

  • CXR
  • CBC
  • CRP
  • blood culture
Full details

Tests to consider

  • dual pulse oximetry
  • ABG (pH, PaO₂, PaCO₂)
  • echocardiography
  • cranial ultrasound
  • electroencephalogram
  • urinalysis
Full details

Treatment algorithm

ACUTE

vigorous infant born through meconium-stained amniotic fluid, no respiratory distress

mild MAS

moderate MAS

severe MAS

Contributors

Authors

Dharmapuri Vidyasagar, MD, MSc, FAAP, FCCM, PhD (Hon)
Dharmapuri Vidyasagar

Professor Emeritus

Department of Pediatrics

University of Illinois at Chicago

Chicago

IL

Visiting Professor

Department of Neonatology

Sri Ramachandra Medical College

Chennai

India

Disclosures

DV is an author of a number of references cited in this topic. He has received royalties for editing the following books: Neonatal Ventilation (Elsevier India), Practical Neonatology (Indian Journal of Pediatrics), and Perinatal Cardiology (Cambridge Scholar publishing).

Rama Bhat, MD, FAAP

Professor of Pediatrics

Department of Pediatrics

University of Illinois at Chicago

Chicago

IL

Disclosures

RB is an author of a reference cited in this topic.

Peer reviewers

Ahmed Osman, MD

Assistant Professor of Pediatrics

Attending Neonatologist

Department of Pediatrics

The Ohio State University and Nationwide Children’s Hospital

Columbus

OH

Disclosures

AO is an author of a reference cited in this topic.

Henry L. Halliday, MD, FRCPE, FRCP, FRCPCH

Professor

Retired Consultant Neonatologist

Royal Maternity Hospital

Honorary Professor

Department of Child Health

Queen's University Belfast

Belfast

UK

Disclosures

HLH declares that he has no competing interests.

John Sinn, MBBS(Syd), Dip Paed, DCH, MMed (Clin Epi), FRACP (Paed)

Clinical Senior Lecturer

Obstetrics

Gynaecology and Neonatology

Royal North Shore Hospital and The University of Sydney

Sydney

Australia

Disclosures

JS declares that he has no competing interests.

  • Meconium aspiration syndrome images
  • Differentials

    • Transient tachypnea of the newborn
    • Surfactant deficiency
    • Persistent pulmonary hypertension
    More Differentials
  • Guidelines

    • 2023 American Heart Association and American Academy of Pediatrics focused update on neonatal resuscitation: An update to the American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care
    • Management of meconium at birth
    More Guidelines
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