title: Retinopathy of Prematurity: Single versus Multiple-Birth Pregnancies.
abstract: OBJECTIVE
  To compare the frequency and severity of retinopathy of prematurity (ROP) among singleton and multiple-birth neonates referred to Farabi Eye Hospital, Tehran- Iran.
  
  
  METHODS
  In this retrospective study, records of 99 consecutive neonates from multiplegestation pregnancies including 68 twins, 26 triplets and 5 quadruplets who were screened for ROP from 2002 to 2004 were reviewed. The frequency, severity and risk factors for ROP were determined and compared to a group of singletons who were matched in terms of gender, birth weight (BW), gestational age (GA), oxygen therapy, respiratory distress syndrome, blood transfusion, sepsis and phototherapy.
  
  
  RESULTS
  ROP was present in 12.1% of multiple-birth neonates as compared to 15.1% of singletons (P=0.53). Threshold ROP was present in 6.1% of multiple-birth neonates versus 7.1% of singletons (P=0.62). ROP was detected in 60% of quadruplets versus 9.6% of twins and triplets; threshold disease was observed in 40% of quadruplets as compared to 4.2% of twins and triplets (P<0.03). However, considering the effect of BW and GA, logistic regression analysis revealed no statistically significant difference in the frequency and severity of ROP among subgroups of multiple-gestation pregnancies.
  
  
  CONCLUSIONS
  There was no significant difference between multiple-birth neonates and matched singletons in terms of frequency and severity of ROP. Any apparent higher rate may be due to independent risk factors such as low birth weight and gestational age rather than multiple pregnancies per se. Screening for ROP in multiple gestation births may be conducted according to standard protocols applied for singletons.
authors.affiliation: Tehran Medical University, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Riazi-Esfahani
authors.forename: Yousef
authors.initials: Y
authors.lastname: Alizadeh
authors.forename: Reza
authors.initials: R
authors.lastname: Karkhaneh
authors.forename: Mohammad-Reza
authors.initials: MR
authors.lastname: Mansouri
authors.forename: Maliheh
authors.initials: M
authors.lastname: Kadivar
authors.forename: Mahdi
authors.initials: M
authors.lastname: Nili Ahmadabadi
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Nayeri