Trauma during pregnancy may be coincidental or related to instability and difficulty moving, especially in the third trimester. It is a consistent cause of maternal death, usually associated with road traffic accidents but also including other forms such as violence, suicide and falls. One per cent of women of childbearing age who suffer major trauma in the UK are pregnant, and pregnant trauma patients tend to have a worse outcome. Fetal mortality rate is up to 50% in major trauma. Although the general principles are the same as in nonpregnant women, the physiological effects of pregnancy and the presence of the fetus impose particular conditions upon the presentation, assessment and management of injured mothers.
Problems and special considerations
The increased metabolic demands of pregnancy make the mother less tolerant of hypotension, poor organ perfusion and hypoxaemia. Assessment of circulating volume status may be complicated by the increased cardiac output, pulse rate and blood volume of pregnancy and the potential for aortocaval compression. Injury to the abdomen and/or pelvis may result in fetal injury, maternal urinary tract injury or severe haemorrhage from the increased vascularity.
Obstetric complications include premature rupture of membranes, premature labour, uterine rupture and placental abruption; the last may occur even with minor trauma and is an especially common cause of fetal death. Fetomaternal haemorrhage may occur, with maternal sensitisation to fetal blood antigens if susceptible.
The fetus is susceptible to the effects of drugs given to the mother.
Management options
General resuscitation is as for any injured patient, following the principles of advanced trauma life support, with the risk of aortocaval compression and gastric aspiration borne in mind. Hypotensive resuscitation is often recommended in trauma patients; however, there is no evidence to support its use in the pregnant patient, and its effects on uteroplacental perfusion will be detrimental to the fetus. Intravenous access should be secured above the diaphragm, where venous return is not compromised by the uterus. If chest drainage is indicated, landmarks may be changed in the presence of a gravid uterus, and drains may need to be inserted at a higher intercostal space. The choice of drugs administered to the mother will be influenced by the stage of the pregnancy. In the early stages, teratogenicity should be considered, and in the second and third trimesters the effect of the drugs on fetal growth and uterine function must be taken into account.
In the management of acute head injury, the normal blood gas values for pregnancy (arterial partial pressure of carbon dioxide approximately 4 kPa) must be remembered, especially if artificial ventilation is required. The risk of acid aspiration should be considered when airway reflexes are obtunded, and early intubation and ventilation may need to be considered.
Many of these women will require diagnostic radiological investigations, especially for head or spinal cord injury. Computerised tomography (CT) requires that the fetus is screened from the ionising radiation. Magnetic resonance imaging (MRI) requires an immobile patient, which may necessitate general anaesthesia with all its attendant risks. Aortocaval compression must be avoided at all times. Access to the MRI scanner may not be possible in an advanced state of pregnancy.
The fetus should be monitored for several hours at least, since placental abruption or fetomaternal haemorrhage may be delayed. In addition, the fetus may have suffered direct injury itself (risk increases with increasing gestational age) or be stressed by any concomitant hypotension, hypoxaemia or maternal therapeutic drugs or manoeuvres (e.g. inotropes, mannitol, furosemide, hyperventilation for control of intracranial pressure).
Caesarean delivery should be for obstetric reasons. Epidural analgesia can be an integral part of the management of labour or operative delivery.
Once the patient is stabilised, definitive surgical management of trauma injuries should follow the principles of non-obstetric surgery in pregnancy (see Chapter 8, Incidental surgery in the pregnant patient).
Key points
• The general principles of managing trauma in pregnancy are as for non-pregnant patients.
• Pregnant women are more susceptible to the effects of hypotension and hypoxaemia.
• Aortocaval compression must be avoided at all times.
• Assessment may be complicated by the physiological changes of pregnancy.
• Placental abruption and fetomaternal haemorrhage are particular risks. The former may be a cause of concealed haemorrhage and unexplained cardiovascular instability.
Further reading
Battaloglu E, Porter K. Management of pregnancy and obstetric complications in prehospital trauma care: faculty of prehospital care consensus guidelines. Emerg Med J 2017; 34: 318-25.
Huls CK, Detlefs C. Trauma in pregnancy. Semin Perinatal 2018; 42: 13-20.
Mendez-Figueroa H, Dahlke JD, Vrees RA, Rouse DJ. Trauma in pregnancy: an updated systematic review. Am J Obstet Gynecol 2013; 209: 1-10.