title: Neonatal and maternal outcomes comparing women undergoing two in vitro fertilization (IVF) singleton pregnancies and women undergoing one IVF twin pregnancy.
abstract: OBJECTIVE
  To compare outcomes for women undergoing two in vitro fertilization (IVF) pregnancies with singletons and women undergoing one IVF twin pregnancy. The concept of single-embryo transfer in IVF has reduced the risks of both maternal and neonatal complications, but there is still a discussion of whether or not twins are a desired outcome of IVF.
  
  
  METHODS
  Registry study.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  All reported twins after IVF with double-embryo transfer (n = 1,982) and their mothers (n = 991) and all mothers (n = 921) who gave birth to two IVF singletons (n = 1,842).
  
  
  METHODS
  None.
  
  
  METHODS
  Maternal and neonatal outcomes including severe neonatal morbidity.
  
  
  RESULTS
  Preterm birth, very preterm birth, low birth weight, very low birth weight, and small for gestational age were dramatically increased for IVF twins compared with two IVF singletons with the same mother, with adjusted odds ratios from 4 to 16. Significantly higher rates of respiratory complications, sepsis, and jaundice were detected among the IVF twins. Significantly higher rates of preeclampsia, preterm premature rupture of the membranes, and cesarean section were observed for IVF twin pregnancies.
  
  
  CONCLUSIONS
  The neonatal and maternal outcomes were dramatically better for women undergoing two IVF singleton pregnancies compared with one IVF twin pregnancy after double-embryo transfer. These results support single-embryo transfer to minimize the risks associated with twin pregnancies.
authors.affiliation: Department of Obstetrics and Gynecology, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg University, Reproductive Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden. antonina.sazonova@vgregion.se
authors.forename: Antonina
authors.initials: A
authors.lastname: Sazonova
authors.forename: Karin
authors.initials: K
authors.lastname: Källen
authors.forename: Ann
authors.initials: A
authors.lastname: Thurin-Kjellberg
authors.forename: Ulla-Britt
authors.initials: UB
authors.lastname: Wennerholm
authors.forename: Christina
authors.initials: C
authors.lastname: Bergh
mesh_terms: D000328:Adult; D001034:Apgar Score; D000013:Congenital Abnormalities / Q000401:mortality; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods* / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000401:mortality; D008297:Male; D009017:Morbidity; D016017:Odds Ratio; D011225:Pre-Eclampsia / Q000401:mortality; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000453:epidemiology*; D047928:Premature Birth / Q000401:mortality; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D056826:Single Embryo Transfer / Q000379:methods* / Q000706:statistics & numerical data*; D014427:Twins / Q000706:statistics & numerical data*; D055815:Young Adult