title: Perinatal outcome of twin pregnancies according to chorionicity: an observational study from tertiary care hospital.
abstract: OBJECTIVE
  To assess the perinatal outcome in twin pregnancies according to chorionicity.
  
  
  METHODS
  This was a retrospective cohort study of twin pregnancies from January 2001 to December 2012. Maternal and perinatal outcomes of monochorionic (MC) and dichorionic (DC) twins were compared by using chi-square and t-test. Perinatal complications were compared by adjusted odds ratio using logistic regression at 5% level of significance.
  
  
  RESULTS
  Among 391 twin pregnancies, 116 (29.6%) were MC and 275 (72.95%) were DC. In MC twins, the rate of miscarriage was three fold higher than DC (12.6% versus 4.4%; p-value<0.000). Mean birth weight in DC was 218.4 g higher than the MC (p value<0.000). Similarly, MC twins were 1.92 times [CI (1.02-3.62), p value=0.042] more likely to be delivered preterm. Likewise, neonatal intensive care admission for MC was 2.23 times [CI (1.08-4.06), p-value=0.03], congenital anomalies were 4.75 times [CI (1.22-18.4), p value=0.024]. Fetal growth restriction was 1.86 times more common in the MC twin pair [CI (1.07-3.21), p-value=0.026].
  
  
  CONCLUSIONS
  MC twins were more at risk for adverse outcomes than DC twins. Determining chorionicity at early pregnancy will help the Obstetricians to plan the care of these patients. This will help not only in managing twin pregnancies but also help in counseling according to the local perinatal outcome.
authors.affiliation: Section of Fetal-Maternal Medicine and Neonatal Health, Aga Khan University Hospital , Karachi , Pakistan.
authors.forename: Shazia
authors.initials: S
authors.lastname: Masheer
authors.forename: Humaira
authors.initials: H
authors.lastname: Maheen
authors.forename: Shama
authors.initials: S
authors.lastname: Munim
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D054238:Perinatal Mortality; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D062606:Tertiary Care Centers / Q000706:statistics & numerical data; D014427:Twins / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: Congenital anomalies; dichorionic twins; monochorionic twins; morbidity; perinatal mortality