title: The effect of intracytoplasmic sperm injection on the early hCG level in twin pregnancies.
abstract: OBJECTIVE
  Since it has been suggested that intracytoplasmic sperm injection (ICSI) might impair the early development of embryos and twin pregnancies have physiologically different aspects from singleton pregnancies, we aimed to investigate the effect of ICSI on the human chrionic gonadotropin (hCG) levels in twin pregnancies.
  
  
  METHODS
  A total of 220 clinical pregnancies which underwent controlled ovarian hyperstimulation and in vitro fertilization/ICSI were analyzed retrospectively.
  
  
  RESULTS
  In twin pregnancies, the mean number of retrieved oocytes and estradiol (E₂) levels on hCG day were significantly higher in ICSI group in spite of lower dose of gonadotropin. The hCG levels according to insemination method did not demonstrate any difference after adjustment for age of patient and partner, BMI, treatment regimens, serum E₂ on hCG day, number of oocytes retrieved and date of sampling.
  
  
  CONCLUSIONS
  The hCG values according to fertilization methods were not significantly different both in twin pregnancies with adjustment for confounders.
authors.affiliation: Department of Obstetrics and Gynecology, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hoon
authors.initials: H
authors.lastname: Kim
authors.forename: Seung-Yup
authors.initials: SY
authors.lastname: Ku
authors.forename: Chang Suk
authors.initials: CS
authors.lastname: Suh
authors.forename: Seok Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Young Min
authors.initials: YM
authors.lastname: Choi
authors.forename: Jung Gu
authors.initials: JG
authors.lastname: Kim
authors.forename: Shin Yong
authors.initials: SY
authors.lastname: Moon
mesh_terms: D000328:Adult; D006063:Chorionic Gonadotropin / Q000097:blood*; D015331:Cohort Studies; D004624:Embryo Transfer / Q000379:methods; D004958:Estradiol / Q000097:blood; D005260:Female; D005865:Gestational Age; D006801:Humans; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D059285:Pregnancy, Twin / Q000097:blood* / Q000502:physiology; D012189:Retrospective Studies; D020554:Sperm Injections, Intracytoplasmic; D013997:Time Factors
chemical_list: D006063:Chorionic Gonadotropin; D004958:Estradiol