Traumatic Brain Injury (TBI): Issues for Pregnancy

Traumatic brain injury (TBI) can have effects that are moderate to severe and is a fairly common cause of disability and mortality in the population overall, but what about during pregnancy? On account of accidents in motor vehicles and other activities, and also sometimes due to falls related to one’s balance being off, particularly toward the end of pregnancy, expectant mothers can suffer TBI. Such cases can lead to complications, including spontaneous abortion (miscarriage), preterm birth, maternal death, and fetal death, leading either to stillbirth or missed abortion. Before continuing with TBI, these complications raise an issue of terminology that we should cover briefly. The term spontaneous abortion applies only to pregnancy loss occurring prior to a gestational age of 20 weeks, meaning the halfway point of pregnancy. In contrast, the term stillbirth, which we mentioned as another potential consequence of maternal TBI, applies to pregnancy loss beyond 20 weeks. Often, the colloquial term miscarriage is applied to pregnancy loss beyond 20 weeks, at least through the second trimester, which ends at the close of the 26th gestational week. The closer the loss occurs to expected time of delivery, the more you will hear people refer to a pregnancy loss as a stillbirth rather than a miscarriage.

Regarding the treatment of victims of TBI victims, there has been a shortage of clinical studies evaluating such treatments specifically in pregnant patients. This is related to the fact that pregnant women often have been excluded from big clinical trials. But experts in TBI and pregnancy health have agreed that such women should be risk stratified, meaning grouped according to the particular set of risk factors and injury level applying to each patient and treated accordingly, factoring in each woman’s set of health conditions, including neurological conditions. Additionally, doctors managing TBI cases factor in the stage of pregnancy, meaning that an injury during the first trimester may be treated very differently from an injury during the third trimester. Women have different vulnerabilities at different times in pregnancy, so the benefit versus risk assessment changes as the pregnancy advances.

Acute types of brain injury, meaning injuries that develop suddenly usually with high severity, include the following:

Concussions: These are the most common type of traumatic brain injury. In concussion, the brain gets shaken around from a sudden blow, causing temporary unconsciousness or at least confusion.

Contusions: These are scattered areas of bleeding on the surface of the brain. Typically, it occurs in the frontal and temporal lobes, in the lower regions and poles.  Contusions often occur together with concussion, but represent more focussed injury, whereas concussions have effects throughout the brain.

Cerebral hemorrhages: This is bleeding in the brain in particular locations

Intracranial hematoma: A hematoma is a gathering of blood that is mostly clotted that forms where there is a space, or a potential space. These are categorized by how deeply that occur in terms of the layers of connective tissue covering the brain. An epidural hematoma is a hematoma between the skull and a layer called the dura matter. These are extremely dangerous and classically the victim loses consciousness and then wakes up for a period before losing consciousness again. A subdural hematoma is a hematoma just beneath the dura mater, causing a potential space, called the subdural space, to open up. An intracerebral hematoma, also called an intraparenchymal hematoma is a hematoma in the brain tissue itself.

Coup-Contrecoup injuries: These terms refer to brain contusions based on their location in the brain with respect to where the injury occurred on the skull.

Diffuse Axonal Injury (DAI): This term refers to damage of the parts of neurons that transmit signals over distances, when it happens spread throughout the brain, which can occur in connection with other types of TBI.

Penetrating Brain Injury: As the name implies, this is a brain injury resulting from penetration of an object through the cranium of the skull.

Second Impact Syndrome: This is a condition resulting from a repeated blow to the head, such as when somebody suffers a concussion before she has recovered from a previous concussion. This can result in long lasting, or permanent damage, which is why, following any concussion, the patient is restricted from activities that can result in head injury.

There is also a condition of which neurologists and other health care providers have been increasingly aware, called chronic traumatic encephalopathy (CTE). This is a degenerative brain condition, characterized by progressive neurological changes that can involve behavior, cognition, mood, and motor function in people who have suffered multiple episodes of head trauma. Prevalence of CTE in the broad human population is unknown, but during the early 2000s it was demonstrated to be common among elite athletes who had engaged in contact sports, especially boxing, American football, and soccer. However, CTE also is common in veterans of military combat and victims of physical abuse. The latter group, sadly can include pregnant women.

Studies of brains obtained during autopsy, the only way to diagnose CTE, suggest that virtually any situation involving repeated jarring of the brain can lead to CTE. Rapid acceleration of the head causes concussion by jarring the brain, making victims of multiple concussion prone to develop CTE. Many concussions are what doctors call subclinical, however, meaning that they alter brain tissue, yet are not reported and diagnosed. Consequently, the mere participation in contact sports is a CTE risk factor.

If you become victim of any kind of head injury while you are pregnant, it is urgent for you go seek care and be evaluated. The evaluation typically centers on a brain imaging scan and a physical examination that emphasizes the neurological exam. There also will be various blood tests and a pelvic or vaginal ultrasound to evaluate the health of your pregnancy.

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

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