title: [Factors associated with assisted reproduction technologies and neonatal outcomes].
abstract: BACKGROUND
  Assisted reproduction technologies can be associated with poor obstetric and perinatal outcomes and an increase in congenital malformations. The objective of this study was to compare obstetric and perinatal outcome of single and multiple pregnancies conceived by IVF (in vitro fertilization) or ICSI (intracytoplasmic sperm injection) with spontaneous pregnancies.
  
  
  METHODS
  A case-control study was conducted on the newborns conceived by IVF and ICSI in Hospital Clínic-Barcelona between January 1999 and December 2005. There were 499 cases reported and 432 controls.
  
  
  RESULTS
  The case group had an increased risk of preterm birth (<37 weeks) and low birth weight (<10th percentile in relation to gestational age and sex). The case group had more multiple births, higher maternal age, more obstetric complications, such as abortion risk, preterm delivery, placental complications, hypertension, gestational diabetes, maternal haemorrhage. There were no significant differences in perinatal outcome, although newborn conceived by IFV/ICSI were admitted to hospital more. In single pregnancies, the case group showed more preterm deliveries and low birth weight, more obstetric complications and more congenital malformations (9.7% vs. 4.3% P=0.046). In multiple pregnancies there were no significant differences in perinatal outcome and incidence of malformations. The case group had a higher incidence of obstetric complications, such as abortion risk, gestational diabetes and hypertension. Although ICSI was associated to more malformations (11.0% vs. 5.6%), there was no significant statistical difference (P=0.099) and the multivariate analysis did not show an independent influence on risk of malformation.
  
  
  CONCLUSIONS
  IFV/ICSI techniques have an increased risk of premature delivery, low birth weight, and poorer obstetric outcomes. Single pregnancies tend to have more congenital malformations. The risk of malformations is not associated with a specific technique.
authors.affiliation: Instituto Clínico de Ginecología, Obstetricia y Neonatología, Facultad de Medicina, Universidad de Barcelona, España Hospital Clinic-Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, España. gsebastiani@hsjdbcn.org
authors.forename: G
authors.initials: G
authors.lastname: Sebastiani
authors.forename: A
authors.initials: A
authors.lastname: Pertierra Cortada
authors.forename: E
authors.initials: E
authors.lastname: Vidal Sordé
authors.forename: J
authors.initials: J
authors.lastname: Figueras Aloy
authors.forename: J
authors.initials: J
authors.lastname: Balasch Cortina