title: First-trimester bleeding and twin pregnancy outcomes after in vitro fertilization.
abstract: To examine the association between first-trimester bleeding and live-birth rates in twin pregnancies conceived with in vitro fertilization (IVF).
  
  
  
  Retrospective cohort study.
  
  
  
  Academic infertility practice.
  
  
  
  Women with two gestational sacs on first-trimester ultrasound after transfer of fresh embryos derived from autologous oocytes between January 1, 1999, and December 31, 2010.
  
  
  
  None.
  
  
  
  Live-birth rate.
  
  
  
  Sixty-five women reported vaginal bleeding, and 288 did not. The baseline characteristics were similar between the two groups, except for an increased prevalence of subchorionic hematoma in women with first-trimester vaginal bleeding (26.2% vs. 1.7%). Live-birth rates were similar between women with bleeding and those with no bleeding (87.7% vs. 91.7%, adjusted odds ratio [OR] 0.73; 95% confidence interval [CI], 0.31-1.73). Two hundred eighty-eight women gave birth to live twins. Among the women who delivered twins, those with first-trimester bleeding had an increased risk of low birth weight of at least one twin (75.0% vs. 59.7%). The association between bleeding and low birth weight persisted after controlling for possible confounders with logistic regression (adjusted OR 2.33, 95% CI, 1.14-4.74).
  
  
  
  Live-birth rates are high in IVF twin gestations, regardless of the presence of first-trimester bleeding. Among women giving birth to IVF twins, however, first-trimester bleeding is associated with increased odds of low birth weight.
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, North Carolina. Electronic address: jennifer.eaton@duke.edu.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Eaton
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Xingqi
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Ralph R
authors.initials: RR
authors.lastname: Kazer
mesh_terms: D000328:Adult; D001724:Birth Weight; D016009:Chi-Square Distribution; D004624:Embryo Transfer; D005260:Female; D005298:Fertility; D005307:Fertilization in Vitro / Q000009:adverse effects*; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007246:Infertility / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D050498:Live Birth; D016015:Logistic Models; D016017:Odds Ratio; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000175:diagnosis / Q000209:etiology*; D011261:Pregnancy Trimester, First; D059285:Pregnancy, Twin; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D016216:Ultrasonography, Prenatal; D014592:Uterine Hemorrhage / Q000175:diagnosis / Q000209:etiology*
keywords: In vitro fertilization; threatened abortion; twins; vaginal bleeding