The Use of Fetal Fibronectin to Predict Delivery Due to Abruptio Placenta
The Use of Fetal Fibronectin to Predict Delivery Due to Abruptio Placenta
The purpose of this study is to determine if the presence of fetal fibronectin in the
 cervicovaginal secretions of pregnant patients with minor maternal trauma predicts impending
 preterm delivery due to abruptio placenta.
Optimal care of the pregnant trauma patient requires prompt and efficient care by a
 multidisciplinary team to evaluate both maternal and fetal status. Approximately 7% of
 pregnancies are complicated by trauma and traumatic injury remains the leading cause of
 non-obstetric maternal death.1-3 In the case of major or life-threatening trauma in
 pregnancy, assessment and stabilization of maternal cardiovascular and respiratory status is
 paramount and management is generally dictated by standard adult advanced cardiovascular
 support algorithms. In contrast, the evaluation and management of minor trauma in pregnancy
 is variable and often provider dependent.4-7 Regardless of the clinical and laboratory
 evaluation performed, the universal goal is to prevent maternal injury or death and optimize
 pregnancy outcomes.

 Maternal trauma has been associated with adverse pregnancy outcome, including preterm labor,
 abruptio placenta, uterine rupture and fetal death.8, 9 Traditional trauma scoring systems
 correlate well with the severity of maternal injury and are useful in triaging the mother;
 however, these scoring systems have not been predictive of adverse pregnancy outcome.10,11
 Major or life-threatening maternal trauma, which includes maternal shock, head injury
 resulting in coma, and emergency laparotomy for maternal indications is associated with a
 40-50% fetal loss rate as compared to 1-5% in pregnant women after minor trauma. The risk of
 preterm labor after maternal trauma is increased 2-fold and the prevalence of abruptio
 placenta after minor blunt abdominal trauma is reported at 8%. 3,6-9,12

 Upon initial evaluation in the obstetrical triage setting, the examination of maternal trauma
 patients is focused on detection of impending labor or abruptio placenta. This evaluation
 includes detailed history of the accident, physical examination, abdominal and transvaginal
 ultrasound to evaluate placental location and/or evidence of placental abruption and cervical
 length, external uterine contraction monitoring, continuous fetal heart rate monitoring and
 blood tests such as CBC, blood type, coagulation profile and Kleihauer-Betke staining.
 Although much has been written on the subject of trauma during pregnancy, there is little
 concrete data on objective measures which can be used to dictate triage and management
 decisions. A recent study by Cahill et al.13 has advocated for review of the extensive
 evaluations often performed after maternal trauma, specifically minor trauma, because they
 determined that none of the commonly used clinical and laboratory measures are predictive of
 adverse outcomes. Identification of laboratory measures predictive of impending delivery due
 to placental abruption will potentially enable physicians to individualize triage and
 evaluation of the maternal trauma patient, as well as direct treatment and management.

 Fetal fibronectin is an extracellular matrix protein that is normally found in the fetal
 membranes and decidua.14 It is essentially an adhesive glycoprotein or "glue" at the
 maternal-fetal interface. In a normal pregnancy, fFN is undetectable in vaginal secretions
 from weeks 22 to 35. Disruption of the maternal-fetal interface causes the release of fFN
 into cervical and vaginal secretions. Detection of fFN before the normal onset of labor is an
 indicator of preterm birth risk, allowing opportunity to provide appropriate intervention.
 According to previous studies, the clinical utility of fFN lies in its negative predictive
 value. In non-trauma patients, the sensitivity of fFN in predicting impending delivery
 (within 7 days) is greater than 90%. A negative fFN result can be used to rule out impending
 deliver with greater than 99% certainty.15

 Because abruptio placenta secondary to maternal trauma is the result of shearing forces
 separating the placenta from the uterine decidua, this outcome could potentially be predicted
 by a positive fFN result. This study is therefore undertaken to determine if the presence of
 fFN in cervicovaginal secretions is predictive of impending delivery or placental abruption
 in patients with maternal trauma. With better knowledge of the probable outcomes following
 maternal trauma and using the appropriate diagnostic and therapeutic modalities, optimal care
 following minor maternal trauma for the pregnant patient and fetus can be provided.
Inclusion Criteria:

 -  Singleton intrauterine pregnancy ≥20 weeks and ≤35 weeks gestational age

 -  Chief complaint of minor maternal trauma including motor vehicle accident, patient
 fall or assault with absence of maternal conditions outlined in exclusion criteria

 Exclusion Criteria:

 -  Maternal shock

 -  Unstable vital signs

 -  Altered sensorium

 -  Head injury resulting in coma

 -  signs or symptoms of intraperitoneal bleeding

 -  Emergency laparotomy for fetal or maternal indications

 -  Bone fractures

 -  History of previous abruptio placenta

 -  Known or suspected placenta previa

 -  Rupture of membranes

 -  Multiple gestation

 -  Advanced cervical dilatation ≥3cm

 -  Non-reassuring fetal status requiring intervention

 -  Vaginal bleeding on presentation

 -  History of intercourse and/or digital vaginal exam and/or vaginal ultrasound ≤24 hours
 prior to presentation

 -  Illicit drug use