Abruptio placentae after auto accidents. A case-control study.

OBJECTIVE: To compare accident and injury characteristics in pregnant women with and without abruptio placentae involved in auto accidents (AAs).

STUDY DESIGN: A retrospective, case-control study involving 12 pregnant women (16-39 weeks) with a diagnosis of abruptio placentae after AAs and 12 control subjects matched for gestational age (+/- 2 weeks) involved in AAs without abruptio placentae from 1988 through 1997. Numerous variables were compared, including restraint system use, estimated speed of the collision, injury severity score (ISS), clinical findings and patient position in the vehicle. Patient complaints and physical examination on admission were also recorded, and obstetric and neonatal outcomes were compared. Statistical analysis was performed using the independent sample t, Mann-Whitney and Fisher's exact tests, when appropriate.

RESULTS: There was no significant difference in the frequency of unrestrained subjects or position in the vehicle between cases and controls. Estimated speed of the vehicle at the time of collision was significantly higher in the abruptio placentae group (> 30 mph, 92% vs. 50%, P = .03), as was the mean ISS code (20 [SD 12.71] vs. 4 [SD 5.13], P < .001). Abdominal pain and vaginal bleeding were seen more frequently in women with abruptio placentae as compared to controls (58% vs. 25% and 33% vs. 0, respectively). Patients with abruptio placentae had a higher incidence of preterm delivery (mean gestational age at delivery = 29 weeks [SD 7.99] vs. 36 weeks [SD 7.21], P = .008) and stillbirth (57% vs. 0%, P = .002) and lower mean birth weight (1,924 g [SD 931] vs. 3,069 g [SD 450], P = .003). There was no significant difference in cesarean section rates between the groups (58% vs. 30%, P = .23). There was no difference in the two groups in placental location on ultrasonography.

CONCLUSION: Pregnant women who were involved in severe accidents (i.e., higher speed or ISS) were more likely to suffer abruptio placentae. In severe accidents, proper restraints were frequently not used. Because of the severity of these accidents, current restraint systems may not be sufficient to prevent abruptio placentae even with proper restraint use. Efforts toward designing new restraint systems for pregnant women should be encouraged.