title: Reproductive outcomes of intracytoplasmic sperm injection (ICSI) in good-prognosis patients who electively decided to limit the number of oocytes used for microinjection: a two-center comparative study.
abstract: OBJECTIVE
  The aim of the study was to compare the outcomes of intracytoplasmic sperm injection/embryo transfer (ICSI/ET) between two IVF centers with similar pregnancy rates and embryo transfer policy but with two different approaches to good-prognosis patients who intentionally chose to limit the number of oocytes used for ICSI.
  
  
  METHODS
  It was a retrospective two-center comparative study A total of 218 patients after successful retrieval of >10 mature oocytes following ovarian hyperstimulation were included in the study The number of fertilized oocytes used during ICSI/ET was limited to 6 and 10 in 108 and 110 patients of the Centre for Reproductive Medicine KRIOBANK and VitroLive Fertility Clinic, respectively
  
  
  RESULTS
  No significant differences in the implantation rate (29.93% vs. 29.54%; p=0.94) and ongoing pregnancy rate (39.81% vs. 45.45%, p=0.40) were observed between patients who electively fertilized 6 as compared to 10 oocytes, respectively However in patients who deliberately limited the number of fertilized oocytes to 6 the following were observed: i) significantly fewer embryos available for ET (2.89 ± 1.23 vs. 3.77 ± 1.48, p<0.0 1); ii) considerably lower number of frozen embryos per cycle (1.05 ± 1.30 vs. 2.00 ± 1.67, p<0.01), and iii) lower rates of cycles with embryo cryopreservation (4 7.22% vs. 72.72%, p<0.01) as compared to patients with 10 fertilized oocytes.
  
  
  CONCLUSIONS
  Elective fertilization of 6 vs. 10 oocytes does not adversely affect fresh ICSI/ET outcome in normal-responding patients. Restricted number of oocytes used for ICSI/ET may be a favorable alternative for couples who do not wish to cryopreserve surplus human embryos.
authors.forename: Przemysław
authors.initials: P
authors.lastname: Ciepiela
authors.forename: Paweł
authors.initials: P
authors.lastname: Kuć
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kuczyńska
authors.forename: Anna
authors.initials: A
authors.lastname: Kazienko
authors.forename: Rafał
authors.initials: R
authors.lastname: Kurzawa
authors.forename: Waldemar
authors.initials: W
authors.lastname: Kuczyński
mesh_terms: D000328:Adult; D015925:Cryopreservation; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000628:therapy*; D008845:Microinjections / Q000706:statistics & numerical data*; D009865:Oocytes; D011044:Poland; D011247:Pregnancy; D018873:Pregnancy Rate; D011379:Prognosis; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic / Q000706:statistics & numerical data*; D016896:Treatment Outcome