Dr Mehul Srivastava
Emergency Registrar

Peer review: Dr Katie Waldman

Editor: Dr Dave McCreary

The Case

It’s a busy Friday night at your regional Emergency Department when a 23-year-old pregnant woman presents with PV bleeding and abdo pain. She is G1P0, estimating 6/40 by LMP. She saw her GP 4days ago, with a BHCG 800.

She has:

  • 12 hours of crampy pelvic pain affecting R > L
  • Light PV spotting, no clots
  • Stable vitals: HR 80, BP 105/70, RR, 15, Sats 98% RA

“What are the chances I’m having a miscarriage, doctor?”

This is a fair and common question, so you need to have an answer ready.

“1 in 4 pregnancies will have bleeding in the 1st trimester.
So this is very common.”

“While most pregnancies will be ok, 10-20% will have a miscarriage. Less commonly, 1-2%  of pregnancies will have something more serious called an ectopic”. [1, 2]

🤓 Editor’s Note:
It’s also really important if you have diagnosed a potential miscarriage, particularly if its the patient’s first, that you reinforce that you aren’t sharing the above statistic in order to minimise in any way the diagnosis, or how the patient will feel about it, but rather to reassure her that it is, unfortunately, quite a natural event and is unlikely to reflect her ability to carry a future pregnancy to term.

While the patient’s first concern is whether she is having  a miscarriage – as Emergency Physicians, our first concern needs to be whether this could, in fact, be an ectopic pregnancy…

What features on assessment can help differentiate an ectopic pregnancy from a miscarriage?

Oh why bother? She needs an US anyway right?

Well… not everyone can get an immediate transvaginal US. Given how common 1st trimester bleeding is, we need to use our clinical assessment to risk stratify these patients. Patients can present in a variety of ways, but these are some of the ‘classic’ symptoms and signs:


  Ectopic Miscarriage
Pain Unilateral, localising Crampy, midline
Risk Factors IUD in-situ, Hx of PID, previous ectopic, IVF Previous miscarriage
Bleeding Variable Variable but can be heavier
Systemic symptoms Syncope, chest pain, shoulder tip pain Less likely

(unless products of conception stuck in cervical os i.e cervical shock)

Examination Localised peritonism.

Adnexal tenderness / cervical excitation.

May or may not be vitally stable.

Could be stable, or cervical shock.


Will you do a vaginal exam (VE) / speculum?

Well, it depends. It helps to think about why we do a VE/speculum.

  1. Remove any products of conception (PoC) in cervical os.
  2. Help you form your pre-test probability and decide urgency of US.

Adnexal tenderness or cervical motion excitation is present in 60-65% of women with ectopic pregnancy [4].

My patient is stable, so I don’t anticipate PoC. However, it is a Friday night and I don’t have access to formal US. Plus, the department is full. I’m trying to decide if I should keep this patient overnight for formal US mane, or if I can discharge her with a planned outpatient US.

The Royal Women’s Guideline suggest that in patients without VE signs of ectopic, they can be discharged for planned early US [3].

Excerpt from Royal Women's Hospital - Flowchart

What about BHCG trends in early pregnancy, and what is the discriminatory zone?


< 8weeks: BHCG doubles every 48hrs [5].
8 – 10weeks: BHCG doubles ~5 days.
> 10weeks: BHCG plateaus.


This becomes important when US shows ‘pregnancy of unknown’ location, as we can then track their BHCG levels in the community.

BHCG Discriminatory zone is the level when a gestational sac should be visible on US [3, 4]:

  • Transvaginal US: 1500-2000 IU/L
  • Transabdominal US: 3000 – 6500 IU/L

A POCUS / FAST scan is really helpful in assessing for free fluid/ruptured ectopic, but remember you may not see a gestational sac if BHCG <3000.

Case Progression

  • History: nil ectopic risk factors.
  • Examination: Right adnexal tenderness, no excitation
  • BHCG: 1200 (from 800 4 days ago)

Given the patient’s ongoing tenderness and that she lived alone, the shared decision was made for observation in ED overnight and an US in the morning.

And the US showed…. Right ectopic in the fallopian tube, unruptured!

Key Take Home Points

  • All patients with 1st Trimester bleeding/pain that haven’t had an US yet, need one. We need to exclude an ectopic.
  • Use your clinical assessment to guide how urgently you need this scan.
  • If your index of suspicion for ectopic is low, do a vaginal exam. If no adnexal tenderness or cervical motion excitation, consider discharge with planned US in 24-48hrs.
  • BHCG doubles every 48hrs. Serial BHCG trends are useful in the community, particularly if the pregnancy is of unknown location. If the pregnancy is confirmed intrauterine on a previous scan, they don’t need further BHCG but rather a repeat US.
  • You can do a POCUS/FAST scan to assess for free fluid, particularly in unstable patients. However, if BHCG <3000IU/L, you may not see the gestational sac to confirm intra-uterine pregnancy.


  1. Everett C. Incidence and outcome of bleeding before the 20th week of pregnancy: prospective study from general practice. BMJ. 1997 Jul 5;315(7099):32-4. doi: 10.1136/bmj.315.7099.32. PMID: 9233324; PMCID: PMC2127042.
  2. Breeze C. Early pregnancy bleeding. Australian Journal for General Practitioners. 2016;45:283-6. Available at: https://www.racgp.org.au/afp/2016/may/early-pregnancy-bleeding#ref-1 Accessed 27th July 22.
  3. The Royal Women’s Hospital. Clinical Guideline: Pain and Bleeding in Early Pregnancy. Available at: https://thewomens.r.worldssl.net/images/uploads/downloadable-records/clinical-guidelines/pain-and-bleeding-in-early-pregnancy_280720.pdf. Accessed 27th July 22.
  4. Sivalingam VN, Duncan WC, Kirk E, Shephard LA, Horne AW. Diagnosis and management of ectopic pregnancy. J Fam Plann Reprod Health Care. 2011 Oct;37(4):231-40. doi: 10.1136/jfprhc-2011-0073. Epub 2011 Jul 4. PMID: 21727242; PMCID: PMC3213855.
  5. Queensland Health. Clinical Guidelines: Early Prengancy Loss. Available at: https://www.health.qld.gov.au/__data/assets/pdf_file/0033/139947/g-epl.pdf. Accessed 28th July 22.
Mehul SriVastava

Mehul SriVastava

Emergency Registrar

MBBS (Hons) BMedSc (Hons) MPH

Mehul is an Emergency trainee with a passion for research and education. She recently published a Cochrane review while working as an Hon. Research Fellow for University College London. She is currently a faculty member with The Alfred Simulation Centre at CHI, teaching final year medical students from Monash University.

Outside of medicine, her passion is dancing. She has been teaching and performing Bollywood dance for >10yrs, with a big focus on using dance to raise cultural awareness and improve wellbeing.