title: First-trimester bleeding and pregnancy outcome in singletons after assisted reproduction.
abstract: BACKGROUND
  First-trimester bleeding is frequent in assisted reproductive technique (ART) pregnancies. It is unknown whether first-trimester bleeding, if not ending in a spontaneous abortion, negatively influences further pregnancy outcome in ART in singletons.
  
  
  METHODS
  Data were obtained from our ART database (1993-2002), with 1432 singleton ongoing pregnancies being included in this study. The outcome measures-second-trimester and third-trimester bleeding, preterm contraction rates, pregnancy duration, birthweight, Caesarean section rates, intrauterine growth retardation (IUGR), preterm prelabour rupture of membranes (P-PROM), neonatal intensive care unit (NICU) admission and perinatal mortality-were compared in the groups with and without first-trimester bleeding.
  
  
  RESULTS
  Significantly more singleton pregnancies resulted from a vanishing twin in the group with first-trimester bleeding (8.7%) than in the controls (4.0%). A correlation was found between the incidence of first-trimester bleeding and the number of embryos transferred. First-trimester bleeding led to increased second-trimester [odds ratio (OR)=4.56; confidence interval (CI)=2.76-7.56] and third-trimester bleeding rates (OR=2.85; CI=1.42-5.73), P-PROM (OR=2.44; CI=1.38-4.31), preterm contractions (OR=2.27; CI=1.48-3.47) and NICU admissions (OR=1.75; CI=1.21-2.54). First-trimester bleeding increased the risk for preterm birth (OR=1.64; CI=1.05-2.55) and extreme preterm birth (OR=3.05; CI=1.12-8.31).
  
  
  CONCLUSIONS
  First-trimester bleeding in an ongoing singleton pregnancy following ART increases the risk for pregnancy complications. The association between first-trimester bleeding, the number of embryos transferred and adverse pregnancy outcome provides a further argument in favour of single-embryo transfer.
authors.affiliation: Infertility Centre, University Hospital Gent, Gent, Belgium. petra.desutter@ugent.be
authors.forename: Petra
authors.initials: P
authors.lastname: De Sutter
authors.forename: Julie
authors.initials: J
authors.lastname: Bontinck
authors.forename: Valerie
authors.initials: V
authors.lastname: Schutysers
authors.forename: Josiane
authors.initials: J
authors.lastname: Van der Elst
authors.forename: Jan
authors.initials: J
authors.lastname: Gerris
authors.forename: Marc
authors.initials: M
authors.lastname: Dhont
mesh_terms: D000033:Abortion, Threatened / Q000209:etiology; D000328:Adult; D001530:Belgium / Q000453:epidemiology; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D005317:Fetal Growth Retardation / Q000453:epidemiology; D006801:Humans; D007752:Obstetric Labor, Premature / Q000209:etiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology / Q000209:etiology*; D011249:Pregnancy Complications, Cardiovascular; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011272:Pregnancy, Multiple; D014427:Twins; D014592:Uterine Hemorrhage / Q000150:complications*