Author: Charlotte Davies, Mark Chester / Editor: Liz Herrieven / Codes: ObC10, ObC11, ObC17, ObC18, ObC19, ObC2, ObC3, ObC6, ObC8, ObC9, ObP1, ObP2, ObP3, ObP7, SLO1 / Published: 14/01/2025

Management of pregnant patients causes much anxiety in the emergency department (ED) as many of us are unfamiliar with the effects of pregnancy on physiology, prescribing and presentations. Many things stay the same in pregnancy, and many things are different. This isn’t an all-encompassing guide, but suggestions of some of the more common considerations. Make sure you remember that resuscitating mum is the best way of looking after the foetus, and that every hospital will have a different system.

ED or MAU?

Determining which patients need ED assessment first, and which need pregnancy assessment first is hard – most hospitals will use gestation (as a surrogate for viability) to decide.

In General:

4   – 12 weeks gestation          ED management + gynae review if needed

12 – 16 weeks                         The grey zone

16 – 24 weeks                         Likely ED first

>24 weeks                              Think: does foetal viability or the presenting problem need assessing first?

24 weeks is considered the minimum gestation for foetal viability, so is considered the cut-off for considering whether foetal viability needs assessing before further management, or whether the presenting condition is critical to mum’s life? The phrase “resus mum to resus the baby” is key here, unless mum is in cardiac arrest and you are considering a resuscitative hysterotomy. Mum needs to be stabilised enough for an anaesthetist to do an anaesthetic to deliver the baby in most cases. It might be that joint care is needed, for example in an eclamptic patient it’s probably best for care to begin in the ED, and Obstetrics will need to stabilise the patient in ED before moving to obstetric theatre. A general guide would be in women >16 weeks pregnant, if their presenting complaint is abdominal or pelvic pain, vaginal bleeding, or reduced foetal movements they should go to / contact the pregnancy assessment unit (PAU) first. Anything else, ED first is fair game. Obviously, pregnant women might present to ED even though they should really be going to PAU because they know ED is fantastic, but seriously consider:

  • Are they booked in (with the midwifery team, for their pregnancy) yet?
  • Are they booked in at a different hospital?
  • Have they an underlying medical condition that they have been told means ED over maternity?
  • Have they rung maternity / GP and been sent to ED?

There are some guidelines available to help us in management of pregnant patients – have a look at the RCP acute care toolkit and the RCOG guidelines.

Modified Early Obstetric Warning Scoring system (MEOWS) helps in early recognition of a deteriorating patient), and most emergency departments are now using this instead of NEWS in the pregnant patient. Abnormal scores should not just be recorded but should also trigger an appropriate response.

  • A normal blood pressure reading is not always a reassuring sign!
  • Systolic blood pressure usually only falls after 1500 ml blood loss (25% of circulating volume).
  • A pink cannula is virtually useless in a pregnant woman.
  • Tachycardia should not be ignored (>100 bpm).
  • Shock index is useful in identifying a deteriorating patient.
  • Tachypnoea should not be ignored (>21 breaths per minute).
  • Respiratory rates over 30 per minute are indicative of a serious problem.

Remember also to use the patient presentation as a public health opportunity to confirm the expectant mother isn’t drinking alcohol, isn’t smoking, is taking the right amount of folic acid (up to 12 weeks), and feels safe at home. Remember those at higher risk of neural tube defects (BMI >30, certain medications, diabetes, sickle cell or thalassaemia, previous pregnancy affected) should take 5mg of folic acid rather than the standard 400mcg.  

Physiology Reminder

  • Changes in blood volume

Blood volume increases by approximately 40%. The increase in plasma volume (40–50%) is disproportionately higher than the increase in red cell volume (20–30%). This causes haemodilution and physiological anaemia of pregnancy which peaks at 34 weeks of pregnancy.

  • The heart rate increases by 10–15 bpm.
  • Stroke volume increases (by 35%) predominantly because of the increased blood volume. The cardiac output increases by up to 50% by the third trimester.
  • Post delivery autotransfusion’ of blood (~500 ml at term gestation) from the contracting uterus following the delivery of the placenta increases blood volume. An oxytocin bolus given intravenously causes acute vasodilation and maternal tachycardia, ergometrine causes vasoconstriction and maternal hypertension.
  • Blood volume returns to normal by 10–14 days postpartum.

The physiological compensatory mechanisms of pregnancy and postpartum may mask signs of blood loss. The drop in blood pressure is a late sign and the loss of blood volume may not be recognised; rising pulse rate is a more useful sign. The shock index (SI) is the ratio of heart rate (HR)/systolic blood pressure (SBP) and is a reliable marker of compromise. Nathan, et al. (2015), in a retrospective study of women with postpartum haemorrhage (PPH), noted that SI compared favourably with conventional vital signs in predicting intensive care unit admission and other outcomes in PPH. The authors established that an SI of less than 0.9 provides reassurance, while an SI greater than or equal to 1.7 indicates a need for urgent attention.

  • Changes in respiratory functions

Oxygen requirement increases by 20% in pregnancy; the tidal volume (TV) and minute volume (MV) increases. The functional residual capacity decreases due to elevation of the diaphragm. Shortness of breath is a normal feature of pregnancy.

The respiratory rate is largely unaltered in pregnancy and a rise in respiratory rate should alert a clinician to a possible deterioration in the woman’s condition.

1.Early Pregnancy

In general, in any patient in early pregnancy, or who may be pregnant, think “could this be ectopic?” and make sure the location of the pregnancy has been confirmed. If the location hasn’t been confirmed, a serum βHCG will be needed. If the location has been confirmed, don’t bother sending a βHCG unless requested by O&G (this could save your department money).  

Bleeding in early pregnancy is covered in this RCEM blog and RCEM reference sections.

Pain in early pregnancy is covered in our ectopic SBA (you’ll need to be logged in).

Patients pregnant after fertility treatment are at higher risk of ectopic pregnancies (although most have an early location scan), and OHSS, but otherwise their pregnancy from an ED point of view has no additional concerns.  

Hyperemesis Gravidarum can be treated well in ED and should also be considered for same day emergency care (SDEC) management. We cover how to treat it in this post, and April 2024 podcast, December 2017 podcast with an SAQ on morning sickness here (again, you’ll need to be logged in).

One important thing to remember is that these patients are high risk for venous-thromboembolism, and so prophylaxis for this should be considered in any management plan.

Constipation is often thought to be a problem in later pregnancy, but the hormonal changes can make early pregnancy difficult too. Refresh your general constipation knowledge with our podcast here.

2. Middle and Later Pregnancy

As pregnancy progresses, patients can present to ED with many symptoms that may or may not be related. Always consider pregnancy-related diagnoses, and non-pregnancy related diagnoses. In later pregnancy (>16 weeks), consider or ask about:

  • Foetal movements (prior to 28 weeks a reduction is hard to quantify but a lack of movements is significant)
  • PV bleeding
  • Fundal height
  • Urinalysis + blood pressure
  • Where a patient’s pregnancy care is booked

For any presentation, whether it immediately seems relevant to the presentation or not, our hospital guidelines require any second or third trimester patient to be reviewed by a midwife or obstetrician to check foetal viability, regardless of presentation, and this is expedited if there are signs of foetal compromise like reduced foetal movements.

Cardiovascular presentations are more likely as pregnancy increases risk of aortic dissection, and spontaneous coronary artery dissection as well as PE as and DVT). Pregnancy makes risk assessing possible VTE harder – the YEARS criteria may still be used. Test your knowledge here. Varicose veins are more likely.

Hypertension has specific management depending on the stage of pregnancy, and there are plenty of guidelines available. This may involve pregnancy-induced hypertension (PIH), pre-eclampsia (PET) and essential hypertension (EH). Our reference section and members only module on HELLP covers PET-related hypertension.

Respiratory presentations are more likely to be severe due to reduced lung capacity. Asthma may worsen in â…“ of pregnancies.

Urological Progesterone makes renal stones more likely in the second and third trimester. Management will be the same as normal renal stones (RCEM reference here, and learning module for members here) – but you might like to do an ultrasound instead of a CT KUB. Remember your discharge advice around fizzy drinks – as summarised in the November 2019 podcast.  Pyelonephritis is more common, although reduced by screening for asymptomatic bacteria, and generally will require inpatient admission even if everything else appears low risk.

Gastro reflux is managed with little and often meals, and anti-acids. I’d check some LFTs in case there’s a sneaking abnormality there. Constipation is covered above.

Musculoskeletal Lower Back Pain is common, and is treated similarly to back pain in the non pregnant patient, with particular attention to safety of prescribing. Be wary of pain out of proportion, as pregnancy associated osteoporosis leading to vertebral fractures exists, although it is very rare.  

Pregnancy Related Pelvic Girdle Pain (previously known as Symphysis Pubis Dysfunction [SPD]) happens in 1:5 pregnancies. The pubic symphysis is a cartilaginous joint, and if it stretches, the two bones of the pelvis can’t be kept together or steady during exercise. If it stretches to >10mm, it is called symphysis pubis diastasis. The joint is supported by four ligaments – the superior pubic ligaments and arcuate ligaments. Pregnancy affects the function of this joint, which can cause significant pain. This may be due to

  • relaxin and pregnancy relaxing the ligament
  • altered pelvic load

This may be exacerbated by anatomical (previous back pain, trauma, obesity) and genetic predisposing factors. Relaxin levels correlate poorly with the severity of symptoms, suggesting that it is more than just hormonally triggered. There is conflicting evidence about the role of maternal age, but it is generally agreed that physically strenuous work can make it more likely. It may start in the first trimester, but more commonly starts in the second or third.

The pain may be anywhere in the pelvic girdle and may radiate to the perineum. It is usually relieved by rest and may be associated with joint clicking on changing position e.g. standing up from sitting, turning in bed. Differentials include osteomyelitis, UTI, round ligament pain, femoral vein thrombosis and obstetric complications. Imaging can be used to measure the inter-pubic distance and confirm the diagnosis, but doesn’t affect management.

Physical examination may reveal:

  • Symphysis pubis pain for >5seconds after palpation
  • Positive Trendelenburg
  • Tenderness of the symphysis pubis, tenderness of sacroiliac joint, positive FABER test
  • Pain on standing on one leg

Manage with hands on physio, analgesia, support devices (although there is limited evidence)  and avoidance of pelvic strain. Support devices like crutches and sacroiliac support belts may help to assist load-bearing. Sleeping with a pillow between the legs can help – and a special Ozzlo pillow may be more effective (Cochrane review) under the abdomen than a normal pillow. Moving should be done with knees together, and it may help to sit down when you get dressed. Activities that involve pelvic strain (eg. vacuuming) should be avoided.

Exercise can help, e.g. walking, stretching, strengthening, pelvic floor. Acupuncture has also been shown to be effective.

Prevention is important – pelvic floor exercises, and other exercises like Pilates can help prevent it.

Dermatological presentations are rare – if your patient is itching, check their LFTs and advise them to inform their midwife in case they have intrahepatic cholestasis and remember pregnancy is a known trigger of erythema nodosum.

Neurological Presentations: Pregnancy can trigger a CN VII nerve palsy (not a Bells if it’s not idiopathic) – make sure their obstetric team are aware if you prescribe steroids, as their glucose may need checking more regularly. Headaches are also common, and as well as all the “normal” presentations, migraine frequency can be increased and harder to manage, and cavernous sinus thrombosis is more likely. Test your knowledge with our member only SAQ here.

Mental Health presentations are possible pre-and post-partum, and again the patient’s obstetric team needs to know if the patient has perinatal mental health team input. Safeguarding and social services referrals may be needed – speak to your mental health team about individual cases. Pregnancy may make it harder to sleep (even in the early stages) and the tips we’ve given you around sleep will also help your patients – but talk about it.

Trauma in pregnancy should be managed similarly to in non-pregnancy. The best thing for mum is the best thing for the foetus. Remember to place the patient in the left lateral position, that all the organs are shifted slightly, anti-D may need to be given and blood loss can be concealed with shock presenting late. Domestic Violence can increase in severity in pregnancy, and every pregnant person should be asked (alone) if they feel safe at home at every available opportunity.

Cardiac Arrest in pregnancy is covered in a blog post here with an SAQ here. And finally, the final presentation in pregnancy will be childbirth, and we should all be ready to catch, as detailed in our blog post here. Any post-partum haemorrhage will be managed by your obstetric team – but refresh your knowledge here. 

Cancer Although most dilemmas concerning cancer in pregnancy involve issues over treatment, diagnosis may be a challenge and should be considered. Typical cancer symptoms mimic general pregnancy complaints, so investigation is often missed or delayed.

Physical examination signs are altered during pregnancy as the gravid uterus may alter anatomical locations and distension or bloating can be disguised by the uterus.

Investigations are more challenging although any potential danger from radiation (CT and X-ray) to the foetus is dependent on gestation and radiation dose. Tumour markers are difficult to interpret as they may rise in pregnancy.

3. Delivery

Have a look at our RCEM reference section on the “patient in labour” , and blog on ED deliveries so you’re ready for the unexpected. Have a read too of our resuscitative hysterotomy blog in the unlikely event of needing it.

If all this has convinced you you’d like to have a baby, have a look at our “What to Expect when you are expecting” blog, and remember, not everyone who doesn’t have children made that  choice, so be careful with the language used.

Useful Guidelines:

References

  1. Cole MF. A modified early obstetric warning system [Internet]. British Journal Of Midwifery. 2014.
  2. Dwyer E R, Filion K B, et al. Who should consume high-dose folic acid supplements before and during early pregnancy for the prevention of neural tube defects? BMJ 2022; 377 :e067728.
  3. National Institute for Health and Care Excellence (NICE). Pre-conception – advice and management. Scenario: Pre-conception advice for all women. NICE CKS. Last revised in April 2023.
  4. Nathan HL, et al. Shock index: an effective predictor of outcome in postpartum haemorrhage? BJOG. 2015 Jan;122(2):268-75.
  5. Meher S, Gibbons N, DasGupta R. Renal stones in pregnancy. Obstet Med. 2014 Sep;7(3):103-10.
  6. The American College of Obstetricians and Gynecologists (ACOG). Urinary Tract Infections in Pregnant Individuals. 2023.
  7. National Institute for Health and Care Excellence (NICE). Dyspepsia – pregnancy-associated: Scenario: Management. NICE CKS. Last revised in June 2024.
  8. Yun KY, Han SE, et al. Pregnancy-related osteoporosis and spinal fractures. Obstet Gynecol Sci. 2017 Jan;60(1):133-137.
  9. Noury L. Trendelenburg’s Test and Trendelenburg’s Gait. Geeky Medics. Updated: 2024.
  10. Thomas IL, et al. Evaluation of a maternity cushion (Ozzlo pillow) for backache and insomnia in late pregnancy. The Australian & New Zealand Journal of Obstetrics & Gynaecology, 1989.
  11. Ozzlo Pillow for Pelvic/Back Pain in Pregnancy. Cochrane Complementary Medicine.
  12. Pubic Symphysis Dysfunction. Physiopedia.
  13. Pelvic pain in pregnancy. NHS.
  14. Pelvic Girdle Pain and other common conditions in pregnancy. Guidance for Mothers-to-be and New Mothers. Pelvic Obstetric & Gynaecological Physiotherapy (POGP), 2018.
  15. Pelvic girdle pain and pregnancy. Royal College of Obstetricians & Gynaecologists, 2015.
  16. Itching and intrahepatic cholestasis of pregnancy. NHS.
  17. Erythema nodosum. DermNet NZ, 2019.
  18. Use of Anti-D immunoglobulin for the Prevention of Haemolytic Disease of the Fetus and Newborn. British Society for Haematology (BSH). 2024