History

The presence of meconium in amniotic fluid is required to cause meconium aspiration syndrome (MAS), but not all neonates with meconium-stained fluid develop this condition. The diagnosis of MAS requires the presence of meconium-stained amniotic fluid or neonatal respiratory distress, as well as characteristic radiographic abnormalities.

Historically, efforts to reduce the development of MAS included oropharyngeal suctioning at the perineum, followed by intubation and tracheal suction of meconium immediately following delivery. This universal practice was abandoned over a decade ago when studies showed that infants who were vigorous at birth did not benefit from this intervention. Following this practice change, the Neonatal Resuscitation Program (NRP) recommended intubation and tracheal suctioning only for nonvigorous infants born through meconium-stained fluid.

However, in 2015, these recommendations changed again: It is no longer recommended to intubate and suction nonvigorous infants born through meconium-stained fluid due to a lack of evidence to support this practice.^{[10, 11]}Instead, in this setting, the NRP now recommends having a practitioner skilled at endotracheal intubation be present at the time of birth, and they should begin with the initial steps of resuscitation (ie, provide warmth, position the head and neck to open the airway, clear secretions with a bulb syringe, dry, and stimulate the infant).^{[10, 11]}The 2017 American College of Obstetricians and Gynecologists (ACOG) opinion number 689 indicates that, regardless of whether infants with meconium-stained amniotic fluid are vigorous or nonvigorous, do not routinely administer intrapartum suctioning.^[11] This opinion was reaffirmed in 2021.^[12]

In a 2015 developing nation retrospective study (2008-2009) that evaluated the effect of intrapartum oropharyngeal suction on MAS in 509 meconium-stained, term singleton neonates without major congenital malformations, investigators found that outcomes in those who received suctioning were similar to those in the control group (who did not undergo suctioning).^[13]The incidence and severity of MAS, as well as oxygen requirements longer than 48 hours, were comparable between the groups.

Physical Examination

Severe respiratory distress may be present. Symptoms include the following:

Cyanosis
End-expiratory grunting
Alar (nasal) flaring
Intercostal retractions
Tachypnea
Barrel chest (increased anteroposterior diameter) due to the presence of air trapping
Auscultated rales and rhonchi (in some cases)

Yellow-green staining of fingernails, umbilical cord, and skin may be also observed.

Green urine may be noted in newborns with meconium aspiration syndrome less than 24 hours after birth. Meconium pigments can be absorbed by the lung and can be excreted in urine.

Differential Diagnoses

Singh BS, Clark RH, Powers RJ, Spitzer AR. Meconium aspiration syndrome remains a significant problem in the NICU: outcomes and treatment patterns in term neonates admitted for intensive care during a ten-year period. J Perinatol. 2009 Jul. 29(7):497-503. [QxMD MEDLINE Link].
Autilio C, Echaide M, Shankar-Aguilera S, et al. Surfactant injury in the early phase of severe meconium aspiration syndrome. Am J Respir Cell Mol Biol. 2020 Sep. 63(3):327-37. [QxMD MEDLINE Link]. [Full Text].
Terasaka D, Clark DA, Singh BN, Rokahr J. Free fatty acids of human meconium. Biol Neonate. 1986. 50(1):16-20. [QxMD MEDLINE Link].
Olicker AL, Raffay TM, Ryan RM. Neonatal respiratory distress secondary to meconium aspiration syndrome. Children (Basel). 2021 Mar 23. 8(3):715-21. [QxMD MEDLINE Link]. [Full Text].
Hermansen CL, Mahajan A. Newborn respiratory distress. Am Fam Physician. 2015 Dec 1. 92(11):994-1002. [QxMD MEDLINE Link].
Yoder BA, Kirsch EA, Barth WH, Gordon MC. Changing obstetric practices associated with decreasing incidence of meconium aspiration syndrome. Obstet Gynecol. 2002 May. 99(5 pt 1):731-9. [QxMD MEDLINE Link].
Balchin I, Whittaker JC, Lamont RF, Steer PJ. Maternal and fetal characteristics associated with meconium-stained amniotic fluid. Obstet Gynecol. 2011 Apr. 117(4):828-35. [QxMD MEDLINE Link].
Macfarlane PI, Heaf DP. Pulmonary function in children after neonatal meconium aspiration syndrome. Arch Dis Child. 1988 Apr. 63(4):368-72. [QxMD MEDLINE Link].
Ghidini A, Spong CY. Severe meconium aspiration syndrome is not caused by aspiration of meconium. Am J Obstet Gynecol. 2001 Oct. 185(4):931-8. [QxMD MEDLINE Link].
[Guideline] Wyckoff MH, Aziz K, Escobedo MB, et al. Part 13: Neonatal resuscitation: 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2015 Nov 3. 132(18 suppl 2):S543-60. [QxMD MEDLINE Link]. [Full Text].
American College of Obstetricians and Gynecologists. ACOG Committee opinion no. 689 summary: delivery of a newborn with meconium-stained amniotic fluid. Obstet Gynecol. 2017 Mar. 129(3):593-4. [QxMD MEDLINE Link].
American College of Obstetricians and Gynecologists. ACOG Committee opinion no. 689 summary: delivery of a newborn with meconium-stained amniotic fluid. American College of Obstetricians and Gynecologists. 2021. Available at https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/03/delivery-of-a-newborn-with-meconium-stained-amniotic-fluid. Accessed: June 20, 2023.
Nangia S, Pal MM, Saili A, Gupta U. Effect of intrapartum oropharyngeal (IP-OP) suction on meconium aspiration syndrome (MAS) in developing country: A RCT. Resuscitation. 2015 Dec. 97:83-7. [QxMD MEDLINE Link].
Boujenah J, Oliveira J, De La Hosseraye C, et al. Should fetal scalp blood sampling be performed in the case of meconium-stained amniotic fluid?. J Matern Fetal Neonatal Med. 2016 Dec. 29(23):3875-8. [QxMD MEDLINE Link].
Liu J, Cao HY, Fu W. Lung ultrasonography to diagnose meconium aspiration syndrome of the newborn. J Int Med Res. 2016 Dec. 44(6):1534-42. [QxMD MEDLINE Link]. [Full Text].
American College of Obstetricians and Gynecologists. ACOG Committee opinion no 579: definition of term pregnancy. Obstet Gynecol. 2013 Nov. 122(5):1139-40. [QxMD MEDLINE Link].
American College of Obstetricians and Gynecologists. ACOG Committee opinion no. 561: nonmedically indicated early-term deliveries. Obstet Gynecol. 2013 Apr. 121(4):911-5. [QxMD MEDLINE Link].
ACOG Committee Obstetric Practice. ACOG Committee opinion number 346, October 2006: amnioninfusion does not prevent meconium aspiration syndrome. Obstet Gynecol. 2006 Oct. 108(4):1053. [QxMD MEDLINE Link].
Velaphi S, Vidyasagar D. Intrapartum and postdelivery management of infants born to mothers with meconium-stained amniotic fluid: evidence-based recommendations. Clin Perinatol. 2006 Mar. 33(1):29-42, v-vi. [QxMD MEDLINE Link].
Hofmeyr GJ, Xu H. Amnioinfusion for meconium-stained liquor in labour. Cochrane Database Syst Rev. 2010 Jan 20. CD000014. [QxMD MEDLINE Link].
Fraser WD, Hofmeyr J, Lede R, et al, for the Amnioinfusion Trial Group. Amnioinfusion for the prevention of the meconium aspiration syndrome. N Engl J Med. 2005 Sep 1. 353(9):909-17. [QxMD MEDLINE Link]. [Full Text].
Davis JD, Sanchez-Ramos L, McKinney JA, Lin L, Kaunitz AM. Intrapartum amnioinfusion reduces meconium aspiration syndrome and improves neonatal outcomes in patients with meconium-stained fluid: a systematic review and meta-analysis. Am J Obstet Gynecol. 2023 May. 228(5S):S1179-S1191.e19. [QxMD MEDLINE Link]. [Full Text].
Committee on Obstetric Practice, American College of Obstetricians and Gynecologists. ACOG Committee opinion no. 379: management of delivery of a newborn with meconium-stained amniotic fluid. Obstet Gynecol. 2007 Sep. 110(3):739. [QxMD MEDLINE Link].
Vain NE, Szyld EG, Prudent LM, Wiswell TE, Aguilar AM, Vivas NI. Oropharyngeal and nasopharyngeal suctioning of meconium-stained neonates before delivery of their shoulders: multicentre, randomised controlled trial. Lancet. 2004 Aug 14-20. 364(9434):597-602. [QxMD MEDLINE Link].
Chettri S, Bhat BV, Adhisivam B. Current concepts in the management of meconium aspiration syndrome. Indian J Pediatr. 2016 Oct. 83(10):1125-30. [QxMD MEDLINE Link].
Wiswell TE, Knight GR, Finer NN, et al. A multicenter, randomized, controlled trial comparing Surfaxin (Lucinactant) lavage with standard care for treatment of meconium aspiration syndrome. Pediatrics. 2002 Jun. 109(6):1081-7. [QxMD MEDLINE Link].
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Media Gallery

Air trapping and hyperexpansion from airway obstruction.
Acute atelectasis.
Pneumomediastinum from gas trapping and air leak.
Left pneumothorax with depressed diaphragm and minimal mediastinal shift because of noncompliant lungs.
Diffuse chemical pneumonitis from constituents of meconium.

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Author

Gina M Geis, MD Attending Neonatologist, Associate Director, Neonatal-Perinatal Medicine Fellowship Program, Albany Medical Center; Assistant Professor, Department of Pediatrics, Albany Medical College

Gina M Geis, MD is a member of the following medical societies: American Academy of Pediatrics, American Society for Bioethics and Humanities, Capital District Pediatric Society

Disclosure: Nothing to disclose.

Coauthor(s)

David A Clark, MD Professor and Martha Lepow Chairman of Pediatrics, Professor of Obstetrics and Gynecology, Albany Medical College; Director, Children's Hospital at Albany Medical Center

David A Clark, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American College of Nutrition, American Forestry Association, American Pediatric Society, Capital District Pediatric Society, Christian Medical and Dental Associations, European Society for Paediatric Research, Eastern Society for Pediatric Research, Floyd W Denny Pediatric Alumni Society, Medical Society of the State of New York, New York Academy of Sciences, Society for Pediatric Research

Disclosure: Nothing to disclose.

Specialty Editor Board

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Brian S Carter, MD, FAAP Professor of Pediatrics, University of Missouri-Kansas City School of Medicine; Attending Physician, Division of Neonatology, Children's Mercy Hospital and Clinics; Faculty, Children's Mercy Bioethics Center

Brian S Carter, MD, FAAP is a member of the following medical societies: Alpha Omega Alpha, American Academy of Hospice and Palliative Medicine, American Academy of Pediatrics, American Pediatric Society, American Society for Bioethics and Humanities, American Society of Law, Medicine & Ethics, Society for Pediatric Research, National Hospice and Palliative Care Organization

Disclosure: Nothing to disclose.

Chief Editor

Dharmendra J Nimavat, MD, FAAP Associate Professor of Clinical Pediatrics, Department of Pediatrics, Division of Neonatology, Southern Illinois University School of Medicine; Staff Neonatologist, Clinical Director, NICU Regional Perinatal Center, HSHS St John's Children's Hospital

Dharmendra J Nimavat, MD, FAAP is a member of the following medical societies: American Academy of Pediatrics, American Association of Physicians of Indian Origin

Disclosure: Nothing to disclose.

Additional Contributors

Ted Rosenkrantz, MD Professor, Departments of Pediatrics and Obstetrics/Gynecology, Division of Neonatal-Perinatal Medicine, University of Connecticut School of Medicine

Ted Rosenkrantz, MD is a member of the following medical societies: American Academy of Pediatrics, American Pediatric Society, Eastern Society for Pediatric Research, American Medical Association, Connecticut State Medical Society, Society for Pediatric Research

Disclosure: Nothing to disclose.

Meconium Aspiration Syndrome Clinical Presentation

History

Physical Examination

References

Tables

Contributor Information and Disclosures

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