title: Natural history of twin gestation complicated by in utero fetal demise: associations of chorionicity, prematurity, and maternal morbidity.
abstract: OBJECTIVE
  To evaluate the pathophysiology by which the in utero death of 1 twin might increase morbidity to its co-twin survivor and its mother. To assess previously reported risks for maternal disseminated intravascular coagulopathy, peripartal hemorrhage, retained placenta and infection, as well as the fetal risk of prematurity.
  
  
  METHODS
  A retrospective analysis of the natural history of twin pregnancies from three institutions was performed. A total of 1,989 cases of twin pregnancy were identified, Wayne State University included 1,266 cases from 1984 to 1993; Madigan Army Medical Center 136 cases, 1995-2000, and Rockford Regional Perinatal Center, 587 cases, 1990-2000. The findings were classified by the presence or absence of fetal death in utero (IUFD) as follows: both IUFD (0/0); 1 IUFD (0/+), and both live born (+/+). A case-control study was performed on the subgroup of patients for whom complete records as to chorionicity, etc., were available.
  
  
  RESULTS
  Of the 1,989 cases reviewed there were 49 both IUFD (0/0), 61 complicated by 1 IUFD (0/+), and 1,879 with both live born (+/+). The overall fetal death rate for this twin cohort was 55/1,000. IUFD of 1 or both twins was related to an increased risk of previable delivery 55% in 0/0, and 28% in 0/+ versus 4% for +/+ with p<0.001. IUFD also was associated with early preterm delivery (mean gestational age at delivery of 23 (0/0) and 30 (0/+) versus 35 (+/+) weeks). Chorionicity as well as maternal risks were examined in the case-control study (24 (0/0), 43 (0/+), 134 (+/+)) with the following results: monochorionic placentation was more likely in pregnancies complicated by IUFD (54% (0/0), 51% (0/+) versus 14% (+/+); p<0.001). Retained placenta, requiring dilation and curettage, occurred more frequently when both twins died in utero, but may be related to the earlier gestational age at delivery.
  
  
  CONCLUSIONS
  Independent of retained placenta, there is no difference in the maternal risks for hemorrhage, abruption, coagulopathy or infection between groups. Immaturity at delivery and monochorionicity are more common in pregnancies complicated by fetal demise. Neonatal morbidity and developmental outcome will be the focus of a longitudinal study comparing cotwin survivors to twins matched for chorionicity and gestational age at delivery.
authors.affiliation: Maternal-Fetal Medicine, Rockford Memorial Hospital, Rockford, IL 61103, USA. obgy6009@med.kobe-u.ac.jp
authors.forename: Howard K
authors.initials: HK
authors.lastname: Kaufman
authors.forename: Roderick F
authors.initials: RF
authors.lastname: Hume
authors.forename: Byron C
authors.initials: BC
authors.lastname: Calhoun
authors.forename: Nancy
authors.initials: N
authors.lastname: Carlson
authors.forename: Victoria
authors.initials: V
authors.lastname: Yorke
authors.forename: Dawn
authors.initials: D
authors.lastname: Elliott
authors.forename: Mark I
authors.initials: MI
authors.lastname: Evans
mesh_terms: D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002821:Chorioamnionitis / Q000453:epidemiology*; D004200:Diseases in Twins / Q000453:epidemiology*; D004211:Disseminated Intravascular Coagulation / Q000453:epidemiology; D005260:Female; D005313:Fetal Death / Q000453:epidemiology*; D005865:Gestational Age; D006801:Humans; D015999:Multivariate Analysis; D007752:Obstetric Labor, Premature / Q000453:epidemiology*; D018457:Placenta, Retained / Q000453:epidemiology*; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D014427:Twins / Q000706:statistics & numerical data