title: Chorionic bump on first-trimester sonography: not necessarily a poor prognostic indicator for pregnancy.
abstract: OBJECTIVE
  The purpose of this study was to determine the live birth rate of pregnancies with a diagnosis of a chorionic bump, a convex bulge from the choriodecidual surface into the first-trimester gestational sac.
  
  
  METHODS
  Pregnant patients at least 18 years old with the finding of a chorionic bump on first-trimester sonography were included in this prospective observational study. The independent variables were chorionic bump size and number and presence or absence of a history of infertility or coagulation disorder. The primary end point was pregnancy outcome.
  
  
  RESULTS
  During the 4-year study period, 52 pregnancies had a diagnosis of a chorionic bump. Overall, 34 resulted in live births, corresponding to an absolute live birth rate of 65%, and 18 were nonviable. Forty-one chorionic bump pregnancies were otherwise normal (ie, pregnancies in which a gestational sac, yolk sac, and embryo with heartbeat were seen at some point), and in this subset, the live birth rate was 83% (34 of 41). All pregnancies with more than 1 chorionic bump (4) ended in demise (100%). The average maximum dimension of the chorionic bump was 1.3 cm (range, 0.5-3.8 cm); however there was not a statistically significant correlation between chorionic bump size and pregnancy outcome (P = .5866; odds ratio, 0.54; 95% confidence interval, 0.06-5.01). Nine patients (17%) had a history of infertility treatment, and 4 (8%) had a history of coagulation disorder. Only 1 chorionic bump pregnancy was associated with a birth defect.
  
  
  CONCLUSIONS
  The live birth rate in our chorionic bump cohort was 65% overall and even higher (83%) if the pregnancy was otherwise normal. The clinical implication is that a chorionic bump on first-trimester sonography is not necessarily associated with a guarded prognosis.
authors.affiliation: New York-Presbyterian/Weill Cornell Hospital, New York, New York USA. ela9033@med.cornelledu.
authors.forename: Elizabeth Kagan
authors.initials: EK
authors.lastname: Arleo
authors.affiliation: New York-Presbyterian/Weill Cornell Hospital, New York, New York USA.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Troiano
mesh_terms: D000328:Adult; D002823:Chorion / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011379:Prognosis; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal
keywords: chorionic bump; first trimester; live birth rate; obstetric ultrasound; pregnancy prognosis; sonograph