123 - Postpartum Emergencies

Originally, the puerperium was defined as the period of confinement during and just after birth; it is now generally accepted to mean the 6 weeks after delivery. The puerperium has also been referred to as “the fourth trimester.” This period is marked by multiple physiologic changes (Table 123.1) as the woman returns to the prepregnant state, including healing physically from any trauma during delivery, and adjusts to the many physiologic and psychologic demands involved in caring for a newborn. Just as in pregnancy, when there are so many physiologic changes, the potential exists for the normal healing process to go awry and emergencies to occur. Certain significant changes in the physiology of the coagulation system during pregnancy persist past delivery and into the puerperium, including major changes in the coagulation and fibrinolytic system, as well as a reduction in venous blood flow in the deep venous system. Combined, these alterations increase the thrombotic potential in near-term and immediate postpartum patients. A pregnant patient around term and immediately postpartum has significant increases in factors I, V, VII, IX, X, and XII; von Willebrand factor antigen; and ristocetin cofactor activity. The endogenous anticoagulants protein C and antithrombin remain unchanged throughout pregnancy, but levels of protein S are reduced. Fibrinolytic activity is impaired during pregnancy as a result of placentally derived plasminogen activator inhibitor type II and pregnancy-induced increases (approximately threefold) in endothelial and hepaticderived inhibitor of plasminogen activator type I. These changes rapidly return to normal following delivery. During normal pregnancy there is a significant reduction in blood flow to the deep venous system, as well as an increase in diameter of the major leg veins. These changes do not occur evenly in both legs. Studies of patients in the puerperium have reported greater diameter and slower blood flow in the left common femoral vein than in the right. These differences are manifested clinically; in nonpregnant patients, the left leg was affected in 55% of cases of DVT, whereas in pregnancy the • The most common infection after childbirth is a genital tract infection. • Because lochia will contaminate a clean-catch specimen in the first 4 to 8 weeks postpartum, urine should be obtained by catheterization in the immediate postpartum period to rule out a urinary tract infection. • In the immediate postpartum period, an acute abdomen may not be manifested as abdominal rigidity on examination because of laxity of the abdominal wall tissue at this time. • Leukocytosis cannot be used to help differentiate an infection in the first 2 weeks postpartum because of the physiologic leukocytosis that occurs during pregnancy and delivery. • Fever is the most important criterion for the diagnosis of postpartum metritis. KEY POINTS