A 29-year-old G3P2 black woman in the 33 week of gestation is admitted to the emergency room because of acute abdominal pain that has been increasing during the past 24 hours. The pain is severe and is radiating from the epigastrium to the back. The patient has vomited a few times and has not eaten or had a bowel movement since the pain started. On examination, you observe an acutely ill patient lying on the bed with her knees drawn up. Her blood pressure is 100/70 mm Hg, her pulse is 110 beats per minute, and her temperature is 38.8°C (101.8°F). On palpation, the abdomen is somewhat distended and tender, mainly in the epigastric area, and the uterine fundus reaches 31 cm above the symphysis. Hypotonic bowel sounds are noted. Fetal monitoring reveals a normal pattern of fetal heart rate (FHR) without uterine contractions. On ultrasonography, the fetus is in vertex presentation and appropriate in size for gestational age; fetal breathing and trunk movements are noted, and the volume of amniotic fluid is normal. The placenta is located on the anterior uterine wall and no previa is seen. Laboratory values show mild leukocytosis (12,000 cells per mL); a hematocrit of 43%; mildly elevated serum glutamicoxaloacetic transaminase (SGOT), serum glutamic-pyruvic transaminase (SGPT), and bilirubin; and serum amylase of 180 U/dL. Urinalysis is normal.
Which of the following is the most likely diagnosis?
A. Acute degeneration of uterine leiomyomaThe most probable diagnosis in this case is acute pancreatitis. The pain caused by a myoma in degeneration is more localized to the uterine wall. Low-grade fever and mild leukocytosis may appear with a degenerating myoma, but liver function tests are usually normal. The other obstetrical causes of epigastric pain, such as preeclampsia may exhibit disturbed liver function (sometimes associated with the hemolysis, elevated liver enzymes, low platelets (HELLP) syndrome), but this patient has only mild elevation of blood pressure and no proteinuria. Acute appendicitis in pregnancy is one of the more common nonobstetric causes of abdominal pain. Symptoms of acute appendicitis in pregnancy are similar to those in nonpregnant patients, but the pain is more vague and poorly localized and the point of maximal tenderness moves to the right upper quadrant with advancing gestation. Liver function tests are normal with acute appendicitis. Acute cholecystitis may cause fever, leukocytosis, and pain of the right upper quadrant with abnormal liver function tests, but amylase levels would be elevated only mildly, if at all, and pain would be less severe than described in this patient. The diagnosis that fits the clinical description and the laboratory findings is acute pancreatitis. This disorder may be more common during pregnancy, with an incidence of 1 in 100 to 1 in 10,000 pregnancies. Cholelithiasis, chronic alcoholism, infection, abdominal trauma, some medications, and pregnancy-induced hypertension are known predisposing factors.
Leukocytosis, hemoconcentration, and abnormal liver function tests are common laboratory findings in acute pancreatitis. However, the most important laboratory finding is an elevation of serum amylase levels, which appears 12 to 24 hours after onset of clinical disease. Values may exceed 200 U/dL (normal values are 50 U/dL to 160 U/dL). Treatment considerations for the pregnant patient with acute pancreatitis are similar to those in nonpregnant patients. Intravenous hydration, nasogastric suction, enteric rest, and correction of electrolyte imbalance and of hyperglycemia are the mainstays of therapy.