Vaginal bleeding in a pregnant woman after 20 weeks gestation is also known as antepartum hemorrhage, and specifically refers to bleeding that is unrelated to labor and delivery.  In the majority of cases, abruptio placentae (30%) and placenta previa (20%) are the underlying causes, with uterine rupture and vasa previa being comparatively more rare.  Antepartum hemorrhage is associated with complications in pregnancy, including preterm labor and birth.  Adverse outcomes are more likely with heavy bleeding, or bleeding from non-previa sources. 

In assessing women with a suspected antepartum hemorrhage, paramedics must establish whether the patient is hemodynamically unstable and begin appropriate treatment while providing safe and expeditious transport.

• Bleeding during pregnancy is worrisome and always warrants further investigation.  Patients showing signs of shock should be treated accordingly.
• The 4 major causes of vaginal bleeding after 20 weeks of gestation are placenta previa, abruptio placentae, uterine rupture and vasa previa.  All represent a medical emergency for both the mother and the fetus.
• A detailed assessment of the patient and a history of current and past pregnancy must be obtained.

• Refer to CPG D01 and D02 for additional details on managing shock and bleeding
  • → D01: Shock
  • → D02: Bleeding
• The management of pregnant women with vaginal bleeding in the second and third trimesters depends on numerous factors, including the gestational age, the cause of bleeding, the severity of bleeding, and fetal status.

• Every patient presenting with bleeding in the 2^nd and 3^rd trimester should be assessed and transported to the closest most appropriate facility
• If the patient is presenting with signs of shock, notifying the hospital ahead of time is likely to improve patient outcome

• A placental abruption (abruption placentae) occurs when the placenta separates from the uterine wall prior to the delivery of the infant.  Risk factors for placental abruptions include trauma, smoking, cocaine use, hypertension, preterm (and pre-labor) rupture of membranes, and a history of prior abruptions. 
• Placenta previa is a condition where the placenta implants and grows over the cervical opening.  Bleeding occurs when fetal growth, or contractions, disrupts the area over the cervix.  Placenta previa should be suspected in any woman with vaginal bleeding in the second half of pregnancy.
• Uterine ruptures are rare causes of vaginal bleeding.  It should be considered in the case of any woman with bleeding, and a history of either previous caeserian delivery or other transmyometrial surgery.  Rupture usually occurs during labor, or as a result of abdominal trauma, though occasionally it happens without any obvious cause.  Abdominal pain, fetal heart rate abnormalities, and hemodynamic instability are common, and are signs of an obstetric emergency.
• Vasa previa occurs when fetal blood vessels are present in the membranes covering the internal cervical os.  These membranous vessels may be associated with either the umbilical cord, or may connect lobes of a bi-lobed placenta.  Rupture of the vasa previa is an obstetric emergency, and can lead to fetal death from exsanguination.

PV Bleed/Threatened Abortion