Diagnosis and Management of Third Trimester Hemorrhage

Etiologies and Diagnosis

The American College of Radiology recommends the use of ultrasound (transabdominal and transvaginal) as the diagnostic modality of choice for third trimester hemorrhage, and digital examination should be avoided until placenta previa, low-lying placenta, and vasa previa are excluded 1, 2
Placenta previa is the most common diagnosed cause by imaging, affecting approximately 1 in 200 pregnancies at the time of delivery, according to the American College of Radiology 1, 2
Abruptio placentae affects approximately 1% of pregnancies, although ultrasound identifies at most 50% of cases, as reported by the American College of Radiology 1, 2
Vasa previa is much less frequent, affecting 1 in 2,500 to 5,000 deliveries, according to the American College of Radiology 1, 2

Transabdominal ultrasound is the primary modality for obstetric imaging, evaluating placental location, placental abruption, and fetal well-being, as recommended by the American College of Radiology 1, 2, 3
Transvaginal ultrasound is particularly useful for cervical causes of bleeding in the second and third trimesters, and has been shown to be accurate and safe for the diagnosis of placenta previa, according to the American College of Radiology 1, 2

For placenta previa and vasa previa, hospitalization is often required, and a scheduled cesarean delivery is typically planned, with absolute avoidance of digital examination, as recommended by the American College of Radiology 1, 2
For postpartum hemorrhage/uterine atony, the American College of Obstetricians and Gynecologists recommends an initial treatment sequence including uterine massage, uterotonic agents, and consideration of surgical interventions such as ligation of uterine or ovarian arteries, and uterine compression sutures 4, 5

Intensive hemodynamic monitoring in the intensive care unit is recommended, with low threshold for reoperation in case of suspected ongoing bleeding, as suggested by the American College of Obstetricians and Gynecologists 5
Close communication between the surgical team and postoperative team is essential, according to the American College of Obstetricians and Gynecologists 5

Third trimester bleeding can lead to adverse perinatal and maternal outcomes, including risk of death, with specific complications including preterm birth, preterm premature rupture of membranes, fetal growth restriction, fetal death, neonatal pulmonary morbidity, and severe fetal anemia, as reported by the American College of Radiology 1, 2