title: Pregnancy complications, obstetric risks, and neonatal outcome in singleton and twin pregnancies after GIFT and IVF.
abstract: OBJECTIVE
  In vitro fertilization (IVF) and to a lower extent gamete intra-fallopian transfer (GIFT) have become routine infertility treatments in industrialized countries. Our purpose is to compare the obstetric and neonatal characteristics of singleton and twin pregnancies after GIFT and IVF with those conceived spontaneously.
  
  
  METHODS
  This case-control study was conducted in a tertiary care medical center. The 322 singleton and 78 twin pregnancies after GIFT or IVF from 1991 through 1996 were evaluated and compared with each other, and with a control group that conceived spontaneously and matched for parity, maternal and gestational age. Statistical significance of differences was assessed by chi(2) test or two-tailed Fisher exact test. Continuous variables were compared by the paired t-test.
  
  
  RESULTS
  Pregnancy-induced hypertension (PIH) and vaginal bleeding were significantly more frequent maternal complications in the GIFT/IVF singleton groups compared to controls. In twin pregnancies the rate of cesarean sections, vaginal bleeding and preterm labor were more common after GIFT/IVF but did not reach statistical significance. Assisted reproduction was associated with low birth weight only in twin pregnancies when controlled for confounding variables, however perinatal outcome was comparable. There was no significant difference in the outcome measures between GIFT and IVF pregnancies.
  
  
  CONCLUSIONS
  After controlling for parity, maternal and gestational age, singleton pregnancies conceived by GIFT/IVF are at increased obstetrical risk, however the perinatal outcome is comparable despite a lower average birth weight.
authors.affiliation: Department of Obstetrics and Gynecology, University Munich-Grosshadern, 81377 Munich, Germany. Robert.Ochsenkuehn@gyn.med.uni-muenchen.de
authors.forename: Robert
authors.initials: R
authors.lastname: Ochsenkühn
authors.forename: Thomas
authors.initials: T
authors.lastname: Strowitzki
authors.forename: Monika
authors.initials: M
authors.lastname: Gurtner
authors.forename: Alexander
authors.initials: A
authors.lastname: Strauss
authors.forename: Andreas
authors.initials: A
authors.lastname: Schulze
authors.forename: Hermann
authors.initials: H
authors.lastname: Hepp
authors.forename: Peter
authors.initials: P
authors.lastname: Hillemanns
mesh_terms: D016022:Case-Control Studies; D002585:Cesarean Section / Q000706:statistics & numerical data; D005260:Female; D005307:Fertilization in Vitro / Q000706:statistics & numerical data*; D015181:Gamete Intrafallopian Transfer / Q000706:statistics & numerical data*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007752:Obstetric Labor, Premature / Q000453:epidemiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011256:Pregnancy Outcome; D011272:Pregnancy, Multiple; D012307:Risk Factors; D014427:Twins; D014592:Uterine Hemorrhage / Q000453:epidemiology