Background: Fetal mortality after trauma is significant. This study was aimed at identifying factors responsible for this high fetal mortality.
Methods: All pregnant trauma patients admitted to the two major Toronto trauma institutions during the period of November of 1991 to February of 1996 with an Injury Severity Score (ISS) > or = 12 were assessed. Data on age, gestation, hypotension, ISS, hemoglobin, blood transfusion, length of stay, disseminated intravascular coagulation (DIC), and specific maternal injury were analyzed retrospectively to determine predictors of fetal mortality by comparison of patients with and without fetal survival.
Results: Twenty of a total of 68 pregnant trauma patients qualified for entry into the trauma registry by having an ISS > or = 12. Overall fetal mortality was 65% (13 of 20) for ISS > or = 12, and there was one maternal death (age, 29 years; ISS, 66). There were no statistically significant differences between the fetal death and fetal survival groups in age (29.2 +/- 6.2 vs. 30.4 +/- 3.9 years), gestation (25.3 +/- 10.5 vs. 24.1 +/- 9.2 weeks), lowest systolic blood pressure (98.3 +/- 33.8 vs. 112 +/- 18.0 mm Hg), head injury rate (3 of 13 vs. 1 of 7), extremity injury rate (8 of 13 vs. 2 of 7), abdominal injury rate (4 of 13 vs. 0 of 7), pelvic fracture rate (6 of 13 vs. 1 of 7), and chest injury rate (5 of 13 vs. 3 of 7). However, ISS (27.7 +/- 3.5 vs. 14.2 +/- 11.4), lowest hemoglobin level (78.8 +/- 17.0 vs. 101.9 +/- 17.1), blood transfusions (10.8 +/- 6.3 vs. 0.9 +/- 1.6 units), length of stay (20.9 +/- 16.7 vs. 8.2 +/- 4.9 days), and the incidence of DIC (8 of 13 vs. 0 of 7) were statistically significantly different between the two groups (p < 0.05). All eight patients with abruptio placentae had associated fetal mortality.
Conclusions: Apart from ISS, blood loss, and abruptio placentae; the presence of DIC was the most significant predictor of fetal mortality. This finding may represent stimulation of DIC by placental products entering the maternal circulation after significant intrauterine injury.