[Trauma and pregnancy: Is the Kleihauer-Betke test really useful?]

To evaluate the pertinence of Kleihauer-Betke (KB) test, in case of abdominal trauma during pregnancy in forecast of fetal outcomes, according to trauma severity.

A single-center retrospective study conducted between January 2014 and April 2016 in a maternity type III and a trauma center, which included the pregnant women admitted for abdominal trauma. The trauma's severity was assessed using the guidelines of the Society of Obstetricians and Gynaecologists of Canada. The impact of a positive KB test, defined as>0.1%, was analyzed. Adverse outcome was defined as one or more of the following complications: intrauterine fetal death, placental abruption, pre-term birth<37 weeks of gestation, and fetal or neonatal anemia.

During the study period, 265 pregnancies involved into an abdominal trauma were included: 69% with a minor trauma and 31% with a severe trauma. Of all patients, 5.6% presented a positive KB test, among then 15.4% had an adverse outcome. There was no significant difference in the rate of adverse outcomes in the positive KB group and the KB negative group either in the overall population (P=0.16), in the minor trauma population (P=1) or in the major trauma population (P=0.14). The predictive positive values were respectively in the global population, in the minor trauma group and in the severe trauma group 15.4%, 0% and 25%.

The KB test does not seem to be useful in case of trauma during pregnancy to define adverse outcome.