Bleeding Complications During Labor
The two most dangerous bleeding complications during labor are placental abruption and placenta previa. A heavy bloody show may be the only sign that alerts the physician to one of these two obstetric emergencies.
Placental abruption occurs when there is premature separation of the placenta prior to birth. It is thought to occur because of disease of the decidua and uterine blood vessels.43 This theory is supported by the strong association between hypertension (both preexisting and pregnancy-induced) and placental abruption. Among women experiencing a placental abruption, about half have hypertension. Other associated risk factors for placental abruption include abdominal trauma, grand multiparity, uterine anomalies, nutritional (folate) deficiencies, short umbilical cord, cigarette smoking, cocaine use, a history of abruption, and advanced maternal age.
Abruptions are classified into one of three types: grade I, not accompanied by fetal distress (40%); grade II, presenting with moderate bleeding and often fetal distress (45%); and grade III, accompanied by severe bleeding that may lead to consumptive coagulopathy and often fetal death (15%).
Third trimester bleeding occurs in 80% of placental abruptions and pain in about 50%. Uterine irritability is common with grade I abruptions; and with increasing severity (grades II and III) contractions may become tetanic. Port wine-stained amniotic fluid may be seen in cases where the hemorrhage dissects through the amniotic membranes with occult abruption. Ultrasonography often does not detect a clot underneath the placenta, and a normal scan should not delay treatment. Abruption remains a clinical diagnosis. There is much overlap of clinical signs and symptoms for the three grades of placental abruption, and a high index of suspicion is important.
The maternal and fetal status must be carefully and continually assessed. Patients are often hemodynamically unstable and intravenous access (peripheral and central) is critical to correct hypotension. Blood products should be immediately available. With mild (grade I) abruption without fetal distress, half of the patients safely deliver vaginally. When a non-reassuring FHR tracing is present, an emergency cesarean section is usually necessary, keeping in mind that disseminated intravascular coagulation (DIC) is uncommon in the presence of a viable fetus. This operative approach results in a lower perinatal mortality rate.44 In the presence of DIC, expeditious delivery of fetus and placenta should be accompanied by use of blood products and fresh frozen plasma. Cryoprecipitate is used sparingly because of its potential to carry blood- borne infections. Heparin has not been found to be of use for this form of DIC.