title: Elevated maternal serum alpha-fetoprotein associated with an asymptomatic tubal pregnancy at 20 weeks' gestation.
abstract: BACKGROUND
  Most tubal ectopic pregnancies become symptomatic in the first trimester and rarely progress to the second trimester. Elevated maternal serum alpha-fetoprotein (MSAFP) has rarely been associated with second-trimester tubal pregnancy. We present a case of a 20-week asymptomatic tubal pregnancy identified by elevated MSAFP.
  
  
  METHODS
  An asymptomatic 22-year-old woman at 20 weeks' gestation was evaluated with a targeted fetal survey for an abnormally elevated MSAFP. The ultrasound examination revealed an extrauterine gestation. The patient was taken to exploratory laparotomy, and a total salpingectomy was performed.
  
  
  CONCLUSIONS
  Although rare, a second-trimester ectopic pregnancy must be considered in the differential diagnosis of elevated MSAFP. A careful ultrasound scan should rule out an extrauterine pregnancy.
authors.affiliation: Department of Obstetrics, University of California, San Francisco, USA. ken@ob.ucsf.edu
authors.forename: K E
authors.initials: KE
authors.lastname: Grullon
authors.forename: V A
authors.initials: VA
authors.lastname: Feldstein
authors.forename: K H
authors.initials: KH
authors.lastname: Lim
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011274:Pregnancy, Tubal / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging; D016216:Ultrasonography, Prenatal; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D000509:alpha-Fetoproteins