You and your partner pull up to a motor vehicle collision. A truck has rear ended a small SUV at a low speed, and there is only minimal damage noted to both vehicles. The police officer on scene tells you the driver of the back vehicle is denying any injury but that the driver of other vehicle is complaining of abdominal pain. As you approach the vehicle with the injured occupant, you see that she's a young female, who is approximately 22 years old. As you get closer, you notice she’s pregnant. Your index of suspicion for injuries has just increased.
Pregnancy creates many physiologic changes. Many of these changes make the evaluation and treatment of a pregnant woman, who has been traumatically injured, challenging. During pregnancy, a woman’s blood volume increases by 45% toward the end of the pregnancy. Her heart rate can increase by 10 to 15 beats per minute, and a decreased vascular resistance results in a decrease in blood pressure. In the later stages of pregnancy, organs are displaced from their original position. The heart is pushed upwards, as is the diaphragm. Abdominal organs are shifted as the fetus grows and the uterus enlarges. As the uterus enlarges with the growth of the fetus, the spinal column curves (kyphosis or lordosis), resulting in lower back discomfort.
Trauma in Pregnancy
Traumatic injuries aren’t uncommon during pregnancy. The American College of Obstetricians and Gynecologist report that one in every 12 pregnancies is complicated by trauma . Common mechanisms for trauma in the pregnant patient are falls, motor vehicle collisions and assaults. When a pregnant patient sustains a traumatic injury, concern arises for the mother and the unborn fetus. And, as the pregnancy progresses risk factors for both the mother and the unborn child change. For example, prior to the 13th week of pregnancy, the fetus is fairly well protected. After the 13th week, however, it becomes more predominant in the abdomen and less protected.
In the case of penetrating trauma to the abdomen (gunshot and stabbing), fetal mortality is higher than maternal mortality. Some literature suggests that pregnant women who sustain penetrating injuries to the abdomen have a lower mortality rate than do those who are not pregnant. This is believed to be secondary to the large uterus displacing the abdominal organs of the mother.
In addition to the injuries commonly associated with traumatic events, such as pneumothorax, fractures and a wide array of abdominal injuries, other injuries must also be considered with evaluating a pregnant patient, who has experienced a traumatic event.
Abruptio placentae and uterine rupture are both associated with trauma in pregnancy. Abruptio placentae is the premature separation of the placenta from the uterine wall. The separation can be partial or total. With the separation, bleeding occurs from the uterus and the placenta, placing both mother and fetus at risk. Both mother and fetus will loose blood, and the fetus can suffer hypoxia since oxygen exchange between the uterus and placenta is altered or stopped. Abruptio placentae commonly presents with abdominal pain, and in many cases, vaginal bleeding. It’s important to remember, however, that in some cases, abruptio placentae occurs without vaginal bleeding. It’s also important to note that there is no direct correlation between mechanism and the presence of abruptio placentae. This is to say that just because the mechanism appears to be minimal, as with the patient above (low speed motor vehicle collision) medical providers cannot rule out the possibility of abruptio placentae.
Uterine rupture is as it sounds; it is the tearing or rupturing of the uterus. The tear can be small, resulting in slow abdominal bleeding, or it can be severe, resulting in the displacement of the fetus and or placenta into the abdominal cavity. This condition has a high mortality rate for mother and fetus. The mother and fetus can become hemodynamically unstable, and the fetus will become hypoxic due to uterine blood loss or placental displacement. Both uterine rupture and abruptio placentae must be considered in any pregnant patient who has sustained a traumatic event, even if the mechanism seems minor.
As mentioned above, all other traumatic injuries must be considered in addition to the injuries specific to the pregnancy. Assessment of these injuries may be difficult. The displacement of abdominal organs makes abdominal evaluation tricky because organs aren’t in their normal positions. Some organs, such as the pancreas, may be put at increased risk for damage. It has been reported that a higher incident of splenic damage is present in pregnant patients as opposed to non-pregnant patients. The upper displacement of the diaphragm causes shortness of breath, which can be difficult to differentiate between shortness of breath due to trauma or secondary to the pregnancy. Position of the patient will play a role as well. When a pregnant patient is placed supine, more pressure is placed on the diaphragm, increasing the shortness of breath.
This can complicate spinal immobilization. An additional complication to spinal immobilization is supine hypotension syndrome. Supine hypotension syndrome occurs when a pregnant patient, usually later in the pregnancy, is placed in a supine position. The weight of the fetus puts pressure in the inferior vena cava, decreasing blood return to the right ventricle of the heart, which decreases cardiac output. The patient’s blood pressure will drop. This can be remedied by tilting the patient to her side moving the fetus off the inferior vena cava. Before tilting a patient on a long board, make sure she is securely strapped.
When assessing a pregnant patient who has been traumatically injured, maintain a high index of suspicion. Any female patient of child bearing age has the potential to be pregnant, and if possible, this should be determined during your assessment. In patients who are further along in their pregnancy, remember to consider the variations in anatomy and the potential life threatening injuries associated with trauma and pregnancy. Supplement the patient’s oxygen with a mask. Establish an IV if you’re able. Follow normal trauma procedures as they relate to immobilization, remembering to accommodate for conditions, such as supine hypotension syndrome. Consider the possibility of abuse because intimate partner violence can increase during pregnancy. Transport to the closest, most appropriate medical facility remembering you have at least two patients.
1. Trauma During Pregnancy. American College of Obstetricians and Gynecologists: Trauma during pregnancy. ACOG Technical Bulletin 161, November 1991.
2. Mirza FG, Devine PC, Gaddipati S. Trauma in Pregnancy: A Systematic Approach. Am J Perinatol. 2010;27(7):579–586.