A case of ectopic pregnancy with a negative urine pregnancy test diagnosed preoperatively as ovarian hemorrhage.

INTRODUCTION: Ectopic pregnancy is a typical obstetric emergency, and serum and urine human chorionic gonadotropin (hCG) measurements are important for its diagnosis. However, qualitative urine hCG tests sometimes give false-negative results. We herein report a case in which pregnancy was ruled out due to a negative qualitative urine hCG test, and surgery was performed based on a preoperative diagnosis of ovarian hemorrhage. However, the pregnancy was ultimately diagnosed as ectopic.

CASE PRESENTATION: The patient was a 19-year-old woman, gravida 0, para 0. She presented to a local clinic for lower abdominal pain that occurred 28 days after her last menstrual period. She was then transferred to our hospital following confirmation of peritoneal irritation signs and abdominal computed tomography (CT) findings revealing ascites. She presented with severe tenderness and rebound tenderness around the umbilicus, and transvaginal ultrasonography revealed an 83-mm hematoma in the Douglas pouch. Since her qualitative urine hCG test was negative and contrast-enhanced CT scans revealed contrast leakage around the left adnexa, a diagnosis of left ovarian hemorrhage was made. Subsequently, emergency laparoscopic surgery was performed. However, the intraoperative finding of left fallopian tube enlargement led to suspicion of an ectopic pregnancy, prompting a change in the surgical procedure to left salpingectomy. Preoperative serum hCG level was elevated at 314 mIU/mL, and pathological examination confirmed chorionic villi, confirming a left fallopian tubal pregnancy.

CONCLUSION: We experienced a case of ectopic pregnancy with a negative urine pregnancy test. In women of reproductive age presenting with an acute abdomen, the possibility of ectopic pregnancy should always be considered, even if the qualitative urine hCG test is negative, and careful informed consent is required.