202 Obstetrics and Gynecology Board Review •••
❍ What is the definition of abruptio placentae?
Premature separation of the normally implanted placenta prior to the birth of the fetus, secondary to bleeding into
the decidua basalis.
❍ What is the incidence of placental abruption?
1%.
❍ What risk factors are associated with placental abruption?
Maternal hypertension.
Advanced maternal parity and age.
Smoking.
PPROM managed expectantly.
Trauma.
Short umbilical cord.
Cocaine use.
Uterine anomalies or myomas.
Sudden decompression of the uterus (either by rupture of the membrane in a patient with polyhydramnios or by
delivery of the first twin).
❍ When is the incidence of placental abruption highest?
24 and 26 weeks.
❍ What are the classic signs and symptoms of placental abruption?
Vaginal bleeding, abdominal pain, uterine contractions, and uterine tenderness.
❍ What is the characteristic uterine contraction pattern associated with placental abruption?
High frequency and low amplitude, with increased baseline tone.
❍ What is a placental abruption without vaginal bleeding called?
Concealed abruption.
❍ What percentage of placental abruptions are concealed?
10% to 20%.
❍ How long should a patient be monitored after significant abdominal trauma late in pregnancy?
4 to 6 hours if fetal heart rate tracing is reassuring and uterine contractions are absent.
❍ How long should a patient be monitored after significant abdominal trauma late in pregnancy with uterine
activity present?
At least 24 hours of continuous electronic fetal monitoring.