In a patient presenting with acute abdominal pain, physical examination usually reveals abdominal tenderness, and there may be an adnexal mass. Signs of peritoneal irritation may be present. Vaginal examination may be normal or may reveal an adnexal mass, cervical motion tenderness, or blood. Vital signs may be normal or may show evidence of shock if significant intra-abdominal blood loss has occurred. Diagnosis of heterotopic pregnancy becomes even more challenging when a woman cannot remember the date of her last menstrual period or has a history of irregular periods.
Abdominal ultrasound is the most commonly performed imaging modality in pregnancy.
It may show a heterotopic pregnancy at the time of initial evaluation in an asymptomatic patient. The diagnostic accuracy is enhanced by also performing an endovaginal ultrasound. The positive predictive value of ultrasound in predicting an ectopic pregnancy has been reported to be from 50 to 95 per cent. 4 Magnetic resonance imaging was reported to be helpful in accurately diagnosing the extrauterine gestation. 5 Limited availability and longer time required to perform make magnetic resonance imaging unsuitable in acute situations.