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Last reviewed: 19 Mar 2025
Last updated: 03 Feb 2023

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • vaginal bleeding with or without clots

Other diagnostic factors

  • suprapubic pain
  • low back pain
  • recent post-coital bleed
  • uterine structural abnormality
  • history of trauma

Risk factors

  • older age
  • uterine malformation
  • bacterial vaginosis
  • thrombophilia
  • parental chromosomal anomaly
  • vitamin D deficiency
  • previous spontaneous/induced miscarriage
  • infertility/assisted conception
  • non-steroidal anti-inflammatory drugs (NSAIDs)
  • caffeine
  • alcohol
  • smoking
  • overweight/obesity
  • thyroid dysfunction
  • diabetes mellitus

Diagnostic investigations

1st investigations to order

  • trans-vaginal ultrasound scan
  • serum beta hCG titres

Investigations to consider

  • transabdominal ultrasound scan
  • serum progesterone
  • urine pregnancy test
  • FBC
  • rhesus blood group
  • lupus anticoagulant/anticardiolipin antibodies
  • pelvic ultrasound
  • cytogenetic analysis on products of conception
  • parental karyotype
  • vaginal swab

Treatment algorithm

Contributors

Authors

Ida Muslim, MBChB, MRCOG

Consultant Obstetrician & Gynaecologist

The Women’s Centre

Gloucestershire Royal Hospital

Gloucester

UK

Disclosures

IM declares that she has no competing interests.

Jothi Doraiswamy, MBBS, MRCOG

Consultant in Obstetrics and Gynaecology

Gloucestershire Royal Hospital

Gloucester

UK

Disclosures

JD declares that she has no competing interests.

Acknowledgements

Dr Ida Muslim and Dr Jothi Doraiswamy would like to gratefully acknowledge Dr Isaac Babarinsa and Professor Tim Draycott, previous contributors to this topic.

Disclosures

IB and TD declare that they have no competing interests.

Peer reviewers

Jo Trinder, MD

Consultant Obstetrician and Gynaecologist

St Michael's Maternity Wing

Bristol Royal Infirmary

Bristol

UK

Disclosures

JT is the primary author of one randomised controlled trial cited in this topic. This trial was funded by an NHS Research and Development Grant and a donation from Exelgyn, the manufacturer of misoprostol. JT has accepted honoraria for speaking to groups of midwives and doctors about miscarriage management.

John Bachman, MD

Consultant in Family Medicine

Parker D Sanders and Isabella Sanders Professor of Primary Care

Rochester

MN

Disclosures

JB declares that he has no competing interests.

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