Signs and symptoms of possible uterine rupture include the following: a change in fetal heart rate pattern from normal to a category 3 heart rate tracing; unexplained vaginal bleeding; frequent epidural dosing or pain that is not alleviated with epidural anesthesia already in place; and loss of uterine tone with an intrauterine pressure catheter (IUPC) in place. If an IUPC is flushed and the patient still has abnormal readings, a diagnosis of uterine scar disruption should be entertained.
In addition to prompt recognition, rapid delivery and blood replacement are key to improving outcomes. The coagulopathy in patients with a ruptured uterus is dilutional rather consumptive, so these patients require replacement not only of packed red blood cells but also of clotting factors and other blood products. As with other types of obstetric hemorrhage, blood loss is usually in excess of the amount perceived.
A recent population-based registry study of 94 identified uterine ruptures after previous cesarean section found that almost half of the mothers diagnosed with uterine rupture after TOLAC (versus during elective or emergency prelabor cesarean section) developed moderate postpartum hemorrhage, while 15% developed severe postpartum hemorrhage and 4% needed peripartum hysterectomy (BJOG 2010;117:809-20).
Perinatal complications occurred in 48 of the 81 (59%) ruptures that occurred after attempted VBAC. In nine (19%) cases, the outcomes were serious (three deaths, three cases of severe asphyxia, and three cases of posthypoxic encephalopathy). To reduce the risk of iatrogenic uterine scar disruption, care should be taken in choosing the appropriate method of induction.
Peripartum Cardiomyopathy
This complication is characterized by the development of heart failure due to significant left ventricular (LV) systolic dysfunction. It is a diagnosis of exclusion. Patients present with the same signs and symptoms characterizing other forms of heart failure secondary to LV dysfunction, and other causes of heart disease and forms of heart failure must be ruled out.
This relatively uncommon myocardial complication can occur up to 5-6 months after delivery, but it usually occurs early in the postpartum period, with about 75% of cases presenting within the first month after delivery (Postgrad. Med. J. 2011;87:34-9). Most patients who are diagnosed during pregnancy present in the third trimester.
Various potential etiologies have been proposed – from viral myocarditis and abnormal hormonal regulation, to excessive prolactin production and an abnormal immune response to pregnancy – but its exact cause is still unknown.
Its incidence in the United States may be increasing. According to a recent review by Dr. Uri Elkayam, the incidence is estimated at approximately 1 in 3,200 deliveries, with a significantly higher incidence (up to 16-fold higher in one study) in African American women (J. Am. Coll. Cardiol. 2011;58:659-70).
Rates as high as 1 in 300 in Haiti and 1 in 100 in a small region of sub-Saharan Africa have also been reported in recent years, according to another review by Dr. Meredith Cruz and her associates (Obstet. Gynecol. Clin. N. Am. 2010;37:283-303).
Certainly, we must all be aware that certain ethnic groups and populations – most notably women of African descent – appear to be more at risk. Pregnancy-related hypertension and preeclampsia also are often cited as risk factors, as are multiparity, obesity, and older maternal age.
Diagnosis requires a high index of suspicion and vigilance, especially because many of the symptoms – shortness of breath, increased peripheral edema, and exhaustion, for instance – are similar to typical symptoms of a normal pregnancy. The diagnosis should be strongly considered in any woman who has nocturnal dyspnea. Chest pain, nocturnal cough, new regurgitant murmurs, pulmonary crackles, increased jugular venous pressure, or hepatomegaly also should raise suspicions, according to the review by Dr. Cruz and her associates.
The timing of delivery in patients diagnosed during pregnancy depends on the maternal status. If the mother is responding to medical management and is stable enough with regard to cardiovascular status to tolerate her heart failure, then induction of labor can be scheduled for or considered at 37 weeks’ gestation. If she is unstable or her LV function is poor or worsening, then early delivery should be considered.
Vaginal delivery often is preferable so that the potential risks associated with anesthesia and surgical delivery, such as clots or infection, can be avoided. Sometimes, however, cesarean delivery may be the only option. For a woman who is laboring, it is important to shorten the second stage of labor, with either low forceps or a vacuum device, in order to minimize pushing and ventricular work.
Management requires teamwork with cardiology, intensive care, anesthesiology, and nursing. After delivery, during a patient’s postpartum fluid shift, she should be managed in a critical care unit or another closely observed setting.