title: Heterotopic pregnancy presenting at 18 weeks' gestational age: a case report.
abstract: BACKGROUND
  Heterotopic pregnancy is a rare event that usually presents in the first 6-8 weeks of pregnancy.
  
  
  METHODS
  A 35-year-old primigravida was referred to the hospital at 18+ weeks' gestational age for evaluation of chronic abdominal pain. Ultrasound revealed a heterotopic pregnancy. The patient underwent surgery for removal of the ectopic pregnancy.
  
  
  CONCLUSIONS
  Heterotopic pregnancy can present at any time during pregnancy and should be considered in any pregnant woman with abdominal pain.
authors: Department of Obstetrics and Gynecology, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA. wmcbee@metrohealth.org
authors: William C
authors: WC
authors: McBee
authors: Stephen P
authors: SP
authors: Emery
authors: Pedro F
authors: PF
authors: Escobar
mesh_terms: D015746:Abdominal Pain / Q000209:etiology; D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000175:diagnosis / Q000209:etiology / Q000473:pathology