Women involved in motor vehicle accidents represent a special group of victims. They have uteruses of varying sizes that are connected only at the base with ligaments and by virtue of the cervix. This uterus is at special risk of injury, especially since it protrudes forward where it can be struck by an oncoming vehicle. The end result can be direct fetal trauma along with maternal trauma or placental abruption, where the placenta tears away from the uterine wall, leading to excessive bleeding and lack of oxygen to the fetus.
Motor vehicle accidents happen to be the leading cause of injury among women who are pregnant. About 1300-13,000 fetal deaths occur in the US each year because of trauma to the mother. In one study, a retrospective look was made using ICD-9 codes that included pregnancy and trauma from emergency department registries. They looked at risks according to fetal age, the mechanism of injury, the actual injuries sustained, whether or not there was loss of consciousness and what the Glasgow coma scale was. The outcome and the injury severity score was also looked at.
At a local hospital between 2001 and 2005, there were 5,244 women who visited the emergency room while pregnant. A total of 294 patients actually reported sustaining an injury and 148 of these women were involved in a motor vehicle collision. The average age of the mother who was injured was 23.8 years and the average gestational age was 20 weeks gestation. Most of the women were drivers of the vehicle involved in the crash (70 percent) with the remainder being passengers. A total of 66 percent of the women were properly restrained at the time of the accident.
None of the mothers died as a result of their accident but seven moms had a poor fetal outcome with six of the fetuses dying and one fetus developing hydrops fetalis. Things that predicted a poor fetal outcome were increased maternal age, loss of consciousness, a high injury severity score and injury to the pelvic region. What this means is that the pelvic region or location of the uterus was an area the women who had the worst outcomes were injured. Women who suffered from head injury severe enough to cause loss of consciousness were also at greater risk.
The doctors who did the study stated that aggressive x-ray taking of the pelvic region needs to be done in pregnant women who sustain a motor vehicle accident, regardless of the fact that the fetus will be exposed to x-ray radiation.
Pregnant women also need to be especially careful of how they buckle themselves into a vehicle. They need to use the standard three-point restraint, taking care to place the lap belt at the level of the pelvic bone. The belt should be fastened snuggly so it doesn’t slip over the uterus.
Accidents with pregnant women cannot be avoided; however, the use of seatbelts and airbags can prevent abruption of the placenta and imminent fetal death.