title: Further considerations on natural or mild hyperstimulation cycles for intrauterine insemination treatment: effects on pregnancy and multiple pregnancy rates.
abstract: BACKGROUND
  The high iatrogenic multiple pregnancy rate associated with intrauterine insemination (IUI) in hyperstimulated cycles is becoming less acceptable. Therefore we investigated data from an earlier prospective trial with regard to the specific question of whether the application of mild hyperstimulation in IUI cycles could be an alternative strategy for obtaining acceptable pregnancy rates while preventing a high multiple pregnancy rate, compared with natural cycles for IUI.
  
  
  METHODS
  Pregnancy outcome of 310 natural and 334 mildly hyperstimulated cycles for IUI in 171 couples with unexplained or mild male factor subfertility was analysed on a patient level with random coefficient models.
  
  
  RESULTS
  Pregnancy rates were similar: 35 and 39.8% per couple in the natural and mildly hyperstimulated cycles respectively (P = 0.60). Multiple pregnancies, all twin pregnancies, were conceived significantly more frequently in the mild hyperstimulation group (27% of the pregnancies) than in the natural cycle group (4% of the pregnancies) (P = 0.01). All multiple pregnancies in the hyperstimulation group were conceived in multifollicular cycles. Multifollicular development was strongly associated with the application of mild hyperstimulation only (odds ratio 21.14, 95% confidence interval 8.15-54.79).
  
  
  CONCLUSIONS
  The application of a mild hyperstimulation protocol as an alternative to a standard hyperstimulation protocol for IUI does not result in higher pregnancy rates than IUI in the natural cycle, while at the same time multiple pregnancies cannot be avoided. Therefore, there is no place for the use of gonadotrophins in IUI treatment.
authors.affiliation: Vrije Universiteit Medical Centre, Department of Reproductive Medicine, Division of Obstetrics and Gynaecology, Amsterdam, The Netherlands. A.J.Goverde@umcutrecht.nl
authors.forename: A J
authors.initials: AJ
authors.lastname: Goverde
authors.forename: C B
authors.initials: CB
authors.lastname: Lambalk
authors.forename: J
authors.initials: J
authors.lastname: McDonnell
authors.forename: R
authors.initials: R
authors.lastname: Schats
authors.forename: R
authors.initials: R
authors.lastname: Homburg
authors.forename: J P W
authors.initials: JP
authors.lastname: Vermeiden
mesh_terms: D000328:Adult; D015331:Cohort Studies; D000075202:Contraindications; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage*; D006062:Gonadotropins; D006801:Humans; D007315:Insemination, Artificial / Q000379:methods*; D008297:Male; D010062:Ovulation Induction / Q000379:methods; D011247:Pregnancy; D018873:Pregnancy Rate; D011272:Pregnancy, Multiple / Q000502:physiology*; D011446:Prospective Studies
chemical_list: D006062:Gonadotropins; D005640:Follicle Stimulating Hormone