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Last reviewed: 21 Apr 2025
Last updated: 04 Jun 2024

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • maternal last menstrual period (LMP)
  • distance from the maternal superior pubis to the uterine fundus
  • infant physical maturity score
  • infant neuromuscular maturity score
  • combined physical/neuromuscular score <10: gestational age <28 weeks
  • combined physical/neuromuscular score 11 to 19: gestational age 29 to 31 weeks
  • combined physical/neuromuscular score 20 to 24: gestational age 32 to 33 weeks
  • combined physical/neuromuscular score 25 to 33: gestational age 34 to 36 weeks

Other diagnostic factors

  • infant birth weight (appropriate for gestational age infants)

Risk factors

  • intra-uterine infection
  • preterm premature rupture of membranes (PPROM)
  • pre-eclampsia/pregnancy-induced hypertension
  • placental abruption/antepartum haemorrhage
  • abnormal amniotic fluid volume
  • severe bacterial vaginosis
  • multiple gestation
  • previous preterm birth
  • fetal abnormality
  • cervical incompetence/uterine abnormality
  • gestational diabetes
  • maternal surgery during pregnancy
  • chronic maternal illness
  • short inter-pregnancy time interval
  • drug use (tobacco, cocaine, heroin)
  • maternal pregnancy body mass index <19 or >35
  • stress/depression
  • extremes of maternal age
  • non-white race

Diagnostic investigations

1st investigations to order

  • fetal biometry during antenatal period

Treatment algorithm

Contributors

Authors

Mohan Pammi, MD, PhD

Professor of Pediatrics

Section of Neonatology and Department of Pediatrics

Baylor College of Medicine

Houston

TX

Disclosures

MP declares that he has no competing interests.

Kushal Bhakta, MD

Associate Professor

Neonatal Intensive Care Unit

Children’s Hospital of Orange County

Orange County

CA

Disclosures

KB declares that he has no competing interests.

Acknowledgements

Dr Mohan Pammi and Dr Kushal Bhakta would like to gratefully acknowledge Dr Stephen Welty and Dr James L. Wynn, previous contributors to this topic.

Disclosures

SW and JLW declare that they have no competing interests.

Peer reviewers

Isaac Babarinsa, MSc, MRCOG

Consultant Obstetrician and Gynaecologist

Gloucestershire Royal Hospital

Gloucester

UK

Disclosures

IB declares that he has no competing interests.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

American Heart Association. AHA guidelines for CPR and emergency cardiovascular care. Part 5: neonatal resuscitation. 2020 [internet publication].Full text

Ballard JL, Khoury JC, Wedig K, et al. New Ballard Score, expanded to include extremely premature infants. J Pediatr. 1991 Sep;119(3):417-23. Abstract

Ng EH, Shah V. Guidelines for surfactant replacement therapy in neonates. Paediatr Child Health. 2021 Feb;26(1):35-49.Full text  Abstract

Reference articles

A full list of sources referenced in this topic is available here.

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