My Most Unusual Case: Cesarean Scar Ectopic Pregnancy
The incidence of cesarean scar ectopic pregnancy is on the rise, in conjunction with the increasing rate of cesarean deliveries. As these patients are at high risk of uterine rupture and hemorrhage, accurate and early diagnosis is the key to limiting maternal morbidity and mortality.
Cesarean scar ectopic pregnancy (CSEP) is a challenging diagnosis that warrants consideration when performing ultrasound on a pregnant patient with a previous history of cesarean delivery. It is suspected when ballooning of the lower uterine segment is noted on ultrasound,1 when a trophoblast is seen at a presumed cesarean scar beneath the utero-vesicular fold, and when myometrium between the gestational sac and bladder wall is thin (<8 mm).2
Ectopic Pregnancy
Ectopic pregnancy affects approximately 2% of all pregnancies and is the leading cause of first-trimester maternal mortality.3 As front-line care providers, it is imperative that emergency physicians (EPs) recognize cases of ectopic implantation to avoid devastating outcomes.
The majority of ectopic pregnancies (97%) are located in the fallopian tubes; however, many other locations are possible, including implantation in the scar from a previous cesarean delivery.1,4 The frequency of such ectopic pregnancies is on the rise, consistent with the increasing number of cesarean deliveries performed worldwide.5 These cases present a special diagnostic challenge because patients often present asymptomatically or with painless vaginal bleeding; moreover, visualization via bedside ultrasound can be deceiving,5 and it is easy to mistake a CSEP for a viable intrauterine pregnancy.
Case
A 22-year-old woman with type 1 diabetes mellitus (DM) presented to the ED complaining of 3 days of worsening nausea and elevated blood glucose levels. She stated that although she had been taking her insulin regimen as prescribed, her symptoms progressively worsened. On the day of presentation, she developed moderate diffuse nonradiating dull abdominal pain and had several episodes of nonbloody, nonbilious emesis. She denied being pregnant and stated that her last menstrual period was 14 days ago; she further denied any vaginal discharge or bleeding. A review of her systems was otherwise benign.
In addition to type 1 DM, the patient also had a history of migraine headaches and an obstetric history of gravida 3, para 3, aborta 0. Each birth was via cesarean delivery and without complication. Her current medications included insulin glargine (Lantus) 25 units subcutaneously every night at bedtime; insulin aspart (Novolog) 7 units subcutaneously three times a day; zolpidem (Ambien) 10 mg orally every night at bedtime. A chart review was notable for several presentations of diabetic ketoacidosis (DKA) secondary to noncompliance with her diabetes regimen.
Physical examination was notable for a well-developed, well-nourished 22 year old that appeared uncomfortable but in no acute distress. Her abdomen was soft and nondistended, with diffuse moderate tenderness to palpation but no rebound or guarding. The remainder of the physical
The initial workup revealed DKA and pregnancy. Significant laboratory values included: finger-stick blood glucose, 441 mg/dL; serum ketones, 2.1 mmol/L (normal range, 0.0-0.5); anion gap, 15; and urinalysis 4+ glucose, 2+ ketones; and quantitative β-human chorionic gonadotropin (β-HCG), 5,282 IU/L (normal range, 0-5.0 IU/L ).examination was otherwise benign.
After receiving insulin, intravenous (IV) fluids, pain medication, and antiemetics, the patient stated she felt much better. She was then admitted to the inpatient floor for management of DKA and discharged uneventfully several days later. Emergency bedside transabdominal and transvaginal ultrasounds were performed by the emergency staff and identified an intrauterine gestational sac and yolk sac. The EP ordered a consultation with an obstetrician-gynecologist (OB-GYN), who saw the patient in the ED and agreed with the findings, and noted the gestational sac was consistent with a date of 5 weeks, 1 day.
Six days after discharge, however, she returned to the ED complaining of several days of weakness, vomiting, and lower abdominal pain. Significant laboratory values included: urinalysis with 4+ ketones, 1+ bacteria, + nitrites; and quantitative β-HCG 25,925 IU/L (expected range, 0-5.0); serum glucose 206 mg/dL; serum ketones 0.8 (expected range, 0-0.5); and anion gap, 12.
An emergency ultrasound identified a gestational sac, yolk sac, fetal pole, and fetal heart tones; an OB-GYN ultrasound had consistent findings, with an estimated gestational age of 6 weeks, 6 days. The patient responded well to IV fluids and antiemetics, and was asymptomatic when she was admitted to the ED observation unit for continued monitoring, fluids, and antiemetics as needed. Several hours later she again began to complain of nausea, vomiting, and poorly localized abdominal discomfort. As these symptoms persisted, the OB-GYN team returned to reevaluate the patient.
