Third-trimester Bleeding

Five to 10 percent of women have vaginal bleeding in late pregnancy. The clinician must distinguish between placental causes (placenta previa, placental abruption, vasa previa) and nonplacental causes (infection, disorders of the lower genital tract, systemic disease). The approach to bleeding in late pregnancy should be conservative and expectant unless fetal distress or risk of maternal hemorrhage occurs.

The patient should be hospitalized and placed at bed rest with continuous fetal monitoring. A complete blood count (including platelets) should be obtained and two to four units of blood typed and cross-matched. Coagulation studies should be ordered as clinically indicated. Ultrasound examination should be performed to determine placental location.

Speculum and digital pelvic examinations are done only after ultrasound study has ruled out placenta previa. Continuous electronic fetal monitoring is required to exclude fetal distress. While uterine contractions, pain, or tenderness often indicate associated abruptio placentae, an ultrasound negative for retroplacental clot does not exclude it.

If the patient is at less than 36 weeks of gestation, continued hospitalization and bed rest may be necessary, especially with placenta previa during the initial 7-10 days following vaginal bleeding. If the patient has close proximity to the hospital and immediate access, can be on strict bed rest, and has complete resolution of bleeding and uterine contractions, home management may be considered. She must be well instructed and counseled regarding the risks. Patients with vaginal bleeding at less than 36 weeks of gestation should also be considered for amniocentesis to test for fetal lung maturity. Steroid therapy (betamethasone 12 mg intramuscularly, two doses 12-24 hours apart) is indicated if fetal lung immaturity is present.

Hladky K et al: Placental abruption. Obstet Gynecol Surv 2002; 57:299.