title: Clinical factors affecting the timing of delivery in twin pregnancies.
abstract: OBJECTIVE
  To investigate clinical factors affecting the timing of delivery in twin pregnancies in order to minimize perinatal complications.
  
  
  METHODS
  A retrospective study involved 163 twin pregnancies delivered from January 2006 to September 2011 at Gachon University Gil Medical Center. These cases were divided into three groups based on the delivery timing: less than 32 weeks' gestation (group A), between 32 and 35+6 weeks' gestation (group B), and over 36 weeks' gestation (group C). Clinical factors including maternal age, parity, presence of premature uterine contraction, presence of premature rupture of membrane, white blood cell, high sensitive C-reactive protein level, cervical dilatation, maternal complication, chorionicity, twin specific complication, and perinatal complication were analyzed for each group.
  
  
  RESULTS
  In group B, the timing of delivery was postponed for 14 days or more from the time of admission, and there were fewer numbers of babies with low Apgar score at birth compared with other groups. The frequency of uterine contraction (P<0.001), presence of premature rupture of membranes (P=0.017), dilatation of cervix (P<0.001), increased white blood cell and high sensitive C-reactive protein levels (P=0.002, P<0.001) were important clinical factors during decision making process of delivery timing in twin pregnancies. Twin specific fetal conditions, such as twin-twin transfusion syndrome and discordant growth (over 25% or more) were shown more frequently in group A. However, there were no significant statistical differences among three groups (P=0.06, P=0.14).
  
  
  CONCLUSIONS
  Proper management for preventing premature contraction and inflammation can be essential in twin pregnancies until 32 weeks' gestation, and may decrease maternal and perinatal complications.
authors.affiliation: Department of Obstetrics and Gynecology, Gachon University Gil Hospital, Gachon University Graduate School of Medicine, Incheon, Korea.
authors.forename: Chae Min
authors.initials: CM
authors.lastname: Lee
authors.affiliation: Department of Obstetrics and Gynecology, Gachon University Gil Hospital, Gachon University Graduate School of Medicine, Incheon, Korea.
authors.forename: Sun Hye
authors.initials: SH
authors.lastname: Yang
authors.affiliation: Department of Obstetrics and Gynecology, Gachon University Gil Hospital, Gachon University Graduate School of Medicine, Incheon, Korea.
authors.forename: Sun Pyo
authors.initials: SP
authors.lastname: Lee
authors.affiliation: Department of Obstetrics and Gynecology, Gachon University Gil Hospital, Gachon University Graduate School of Medicine, Incheon, Korea.
authors.forename: Byung Chul
authors.initials: BC
authors.lastname: Hwang
authors.affiliation: Department of Obstetrics and Gynecology, Gachon University Gil Hospital, Gachon University Graduate School of Medicine, Incheon, Korea.
authors.forename: Suk Young
authors.initials: SY
authors.lastname: Kim
keywords: Maternal complications; Perinatal complications; Timing of delivery; Twins