Trauma in pregnancy: Core knowledge and key skills. St Emlyn’s

written by Anisa Jafar @EmergeMedGlobal and Anthony Joseph

“Trauma standby: approximately 34 weeks pregnant female driver, 50 mph road traffic accident, air-bag deployed no obvious injuries, SpO2 99%, HR 95, BP 120/85, RR 16. ETA 15 minutes”

Whether it’s the red phone or a simulation on a trauma course, the word “pregnant” brings most of us emergency folk out in some sort of cold sweat.  And so it should. In our speciality, timely and specific decision-making is everything. When our unstable trauma patient is pregnant, in the third trimester especially, that decision-making is tested to its limit.

In the best-case scenario, the ultimate outcome is two healthy lives, in the worst, two lives are lost. In between that there is the emotional jeopardy of moving from a mental model of trying to save two lives to a mental model that necessarily focusses on the life of the mother, with foetal well-being as a positive by-product of successful maternal resuscitation.  And yet, we need to remain mentally and practically prepared to resuscitate both mother and baby especially in the most extreme cases where a peri-mortem caesarean section (C-section) becomes imperative.  

It’s a lot. So, we thank Anthony Joseph (trauma consultant and senior emergency physician at Royal North Shore Hospital in Sydney and associate professor at the University of Sydney) for his very practical presentation at this year’s online ICEM conference and providing the material from which we’ve written this blog. By being armed with a bit of knowledge and reminded how to manage the pregnant trauma patient, we can divert some of that cold sweat and adrenaline to confidently getting on with the job and leading the team to the best outcome possible.

Importance of injury in pregnancy

Although the exact incidence is unknown, injury is estimated to occur in 1 in 12 pregnancies and is actually the leading cause of non-obstetric maternal death.   Of course, there are two stories to tell here and depending on the stage of pregnancy, the impact of injury on the foetus may result in:

  • increased risk of miscarriage
  • premature rupture of the membranes and premature birth
  • placental abruption
  • uterine rupture
  • stillbirth

Around half of the injuries we will see in pregnant women will be following road traffic collisions, however this patient group are also at a higher risk of falls especially as gestation progresses.  Data suggests that around a quarter of pregnant women have at least one fall.

Interestingly burns, whilst uncommon, should raise the hair on the back of your neck because once the total burn surface area approaches 40%, maternal and foetal mortality approach 100 % due to the significant physiological stress.

Intimate partner violence is variable in its relative incidence as compared to pre-pregnancy. In some cases, pregnancy is a protective factor, whilst in others it is an exacerbating factor. What does this mean for us? We need to consider each case individually as potentially higher risk.

Preparation prevents p*** poor performance

One of the problems faced when managing major trauma in pregnancy is that most trauma centres see and treat seriously injured pregnant trauma patients relatively infrequently. So it is really important that the trauma team drill the obstetric trauma scenario both regularly and alongside obstetric, anaesthetic & neonatal friends (might want to make that “best friends” as you’d want them to be in this situation)

Your other best friends are of course the nursing team in the resus room as they will (if you’ve drilled it regularly) know where the vaginal delivery and emergency C-section instrument sets are as well.  Making sure the whole team are familiar with their location, what is inside and how to use them will save invaluable time. It will also turn an unfamiliar and stressful situation into one where staff feel a little more in control.

If there is any hint from the pre-alert that this is significant trauma, you should also alert the midwifery team to bring cardiotocography (CTG) to the department.

Your patient arrives with a paramedic crew, they’ve cannulated and given some IV paracetamol, the patient is clearly in her third trimester and whilst visibly upset, appears to remain stable

So, it must be ABCDE to the power of 2?

Not quite. The initial assessment is almost exactly the same as any other trauma patient however there are a few modifications to keep at the forefront of your mind especially as a trauma team leader. One of the first, which should be verbalised if known, during the team preparation time is this: 

pregnancy greater than 20 weeks with a significant mechanism and/or abnormal vital signs should alert the team to potentially significant – possibly occult – pathology

Assuming the patient passes the 5-second round (terminology from the European Trauma Course which poses three questions of the arriving patient: is the airway imminently at risk? do they have ex-sanguinating external haemorrhage? are they pulseless?) with a resounding “NO” then the initial primary survey begins as normal, focusing on one patient: the mother. The viability of the foetus depends on the cardio-respiratory wellbeing of the mother therefore anything you do to improve her clinical condition will increase foetal well-being.

This principle should also apply to imaging – if it is needed, do it. The amount of radiation from the CT scan is negligible in terms of foetal abnormality/loss of pregnancy.

At this point it is probably worthwhile to review some of the physiological and anatomical changes to be found in pregnancy which will play in to the primary survey

  • Especially in the third trimester, if that airway needs securing a difficult airway should be anticipated: relative airway oedema, reduced oesophageal sphincter tone and delayed gastric emptying.  Senior anaesthetist please!
  • If circumstances dictate an RSI, then you need it to save the mother which then saves the baby, so you use the right drugs for her HOWEVER if you then need to deliver, due to induction/sedating agents crossing the placenta, a flaccid, apnoeic baby should not come as a surprise, and appropriate neonatal support should be at the ready
  • Pre-oxygenation is especially important prior to attempts at intubation due to reduced functional residual capacity: she will desaturate fast.
  • So, you need to insert a chest drain? Go one space higher than you might usually (go 4th intercostal space) to avoid that elevated diaphragm from the gravid uterus
  • Beware occult shock.  With 50% greater plasma volume and 10-15% expanded red-cell mass, she may physiologically compensate well for up to two litres of blood loss. Scary, huh?

Now unfortunately the foetus really becomes your friend in this circumstance: foetal distress on CTG is the earliest sign of maternal hypovolaemia and shock.

How so? Bucket loads of catecholamine receptors in the utero-placental blood vessels and uterine wall means that maternal blood loss triggers vasoconstriction in a big way, to shunt blood back into her circulation.

So, get that CTG on and use all of the information you can.

  • Utero-caval compression (uterus reducing venous return via pressure on the IVC) is the last thing you need as it will result in reduced cardiac output.  You have two options.  One of these options is NOT however a wedge directly under the patient – this could destabilise spinal/pelvic injuries. So, what is left?
    • Tilting the patient to the left on a backboard at angle of 15-30 degrees
    • Manual displacement of the uterus

Which of these you do will depend on logistics of achieving the tilt and/or the number of hands you have available, because once those hands are on, they should really stay on to maintain the benefit.

  • Reach back to your medical school brain files and remember to add in the Kleihauer-Betke if you think the patient could be Rhesus negative (Rh-). This will give clues to foetal-maternal haemorrhage will subsequently guide the need for Anti-D immunoglobulin to avoid haemolytic disease of the newborn in this or future pregnancies.
  • Whoever is assessing disability and therefore talking to the patient should, if acuity allows, take a moment to reassure her that the team is doing everything they can to look after her and her baby.  If she is awake and aware, her levels of anxiety and distress will very likely be off the scale.
  • Try to establish if there have been any pregnancy complications to help the team anticipate potential issues with either mother or baby – pre-eclampsia in particular should be asked about.
  • Worth remembering, as you examine, a few milestones
    • 1st trimester uterus is protected by the pelvis up to 12 weeks
    • 2nd trimester amniotic fluid protects the foetus and the fundus reaches the umbilicus at 20 weeks
    • 3rd trimester the uterus is thin walled, at risk of damage due to direct blunt or penetrating trauma and reaches the costal margin at 36 weeks
    • If the foetal head is engaged in the pelvis, it is at risk of injury if the mother has a fractured pelvis
Uterine size in Pregnancy https://www.ewomenclinic.com/article_post.php?id=NjU=
  • The secondary survey should be as normal but with the added assessment of:
    • Uterine size, tenderness and contractions
    • Vaginal bleeding
    • Evidence of cord prolapse following ruptured membranes (this is urgent c-section territory with the cord manually pushed back into the uterus)
    • Bulging perineum indicating imminent delivery

Apart from some small seatbelt marks across the chest and lower abdomen and very mild discomfort on pressing these areas, the primary survey reveals no abnormalities

Ok so CTG, we need CTG… what do I remember about CTGs?

When do we need one?

After 20 weeks’ gestation with any suspicion of overt/occult uterine injury and/or suspicious of occult haemorrhage

What is normal?

         A foetal heart rate (FHR) of 110-160 bpm with normal beat to beat variability of 5-25 bpm

What happens to the FHR in maternal compromise?

         Loss of beat to beat variability

         As well as initial tachycardia, then bradycardia – FHR <110 is bad news

         To the trained eye (midwife, HELP), variability between beats will be lost early on

         Any decelerations on the CTG are a bad sign

Anything else?

         The CTG will pick-up abnormal contractions, which may be a sign of placental abruption

The patient has no pain and no signs of shock, the FHR seems fine – how long do I monitor for?

         This decision should be coming from, or in conjunction with, the Obstetric team

         Occult placental abruption is unlikely if there is less than 1 contraction in any 10-minute period over 4 hours

CTG: variable decelerations http://eknygos.lsmuni.lt/akuserijaen/Obstetrics/4%20CTG%20engl.html

The patient isn’t sure if foetal movements are as often, it has been such a stressful morning but she now feels some ‘tightenings’ which she has had before, but not so many or so strong… The midwife arrives with the CTG: the foetal heart rate is 100, and there are decelerations associated with contractions. She fast bleeps the obstetrician… no sooner can the team blink than the patient is whisked away to maternity theatres.

Placental abruption and uterine rupture, these sound nasty…

These are two conditions which should be considered in any blunt trauma to the pregnant abdomen in the third trimester.  Ultrasound is not very sensitive for abruption, whereas CTG is.

Placental abruption
Maybe asymptomatic or painful contractions/tender uterus/vaginal bleeding
Around 50% foetal mortality
CTG: suspicious if FHR <110/>160 or early/late decelerations associated with contractions
Usually presents within a few hours – can take up to 72 hours
Minimum 24 hours CTG if contractions/bleeding
Minimum 4 hours CTG if asymptomatic & CTG reassuring
Urgent c-section if signs of foetal distress
Uterine rupture
Rare: <1% injured pregnant patients
Direct uterine trauma from large force
Risk factors: late pregnancy, previous uterine surgery
High foetal mortality
Major haemorrhage possible
May be clinically occult
Emergency hysterectomy if bleeding uncontrolled

And if you get a pregnant, traumatic cardiac arrest?

A couple of points:

  • One of the most anxiety – producing surgical procedures you are ever likely to perform
  • Peri-mortem c-section should ideally be performed within 4-6  minutes of maternal cardiac arrest in a woman at least 23 weeks pregnant (can be done up to 15-20 mins after maternal cardiac arrest)
  • It may result in a live baby (see Perimortem C-section at St.Emlyns) and may facilitate maternal and/or neonatal resuscitation
  • Deciding and preparing to do it should be synchronous with recognising that the patient is going to arrest, every minute lost in deciding to do it post-arrest reduces the chance of either mother or baby surviving

Take home

Manage the trauma like any trauma case with the ABCDE

Add in these crucial bits of extra thinking

Remember left lateral position

Beware reassuring physiology

Get expert help (in training and in situ)

Use the CTG

Manage the mother to save the baby

References

  1. Mendez-Figueroa H, Dahlke JD, Vrees RA, Rouse DJ. Trauma in pregnancy: an updated systematic review. American journal of obstetrics and gynecology. 2013 Jul 1;209(1):1-0

2. Rudloff U. Trauma in pregnancy. Archives of gynecology and obstetrics. 2007 Aug;276(2):101-17

3. Murphy NJ, Quinlan JD. Trauma in pregnancy: assessment, management, and prevention. American family physician. 2014 Nov 15;90(10):717-22

4. Trauma in Pregnancy. In Moore EE, Feliciano DV, Mattox KL, eds. Trauma 8th ed, New York: McGraw-Hill education, 2017:



Cite this article as: Anisa Jafar, "Trauma in pregnancy: Core knowledge and key skills. St Emlyn’s," in St.Emlyn's, September 28, 2021, https://www.stemlynsblog.org/trauma-in-pregnancy-core-knowledge-and-key-skills-st-emlyns/.

Posted by Anisa Jafar

NIHR Academic Clinical Lecturer in Emergency Medicine based clinically at Manchester Foundation Trust. She completed her PhD at the Humanitarian and Conflict Response Institute in 2019 in the area of medical-record keeping in sudden onset disasters. Her academic clinical training in Emergency Medicine has taken place mainly in North West England. She completed her DTM&H at the Liverpool School of Tropical Medicine and her MPH from the University of Manchester.

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