title: The prognostic value and significance of preclinical abortions in in vitro fertilization-embryo transfer programs.
abstract: Preclinical abortions occur in natural conceptions as well as in in vitro fertilization-embryo transfer (IVF-ET) cycles. Nevertheless, although known, this entity is ill defined.
  
  
  OBJECTIVE
  The purpose of this study was to propose a classification of these pregnancies on the basis of pathophysiological evidence and to evaluate their future clinical impact.
  
  
  METHODS
  Of 970 IVF-ET cycles, 114 cycles (11.7%) terminated in preclinical abortions. Abortions were divided according to peak beta human chorionic gonadotropin (beta-hCG) values into chemical abortions (52%) occurring 2 weeks after ET with beta-hCG values not higher than 21 mIU/mL and peri-implantation abortions (47%) terminating spontaneously 4 weeks after ET; the latter had higher beta-hCG values for a longer period of time but without any sonographic evidence of gestational sac. No woman in the two groups needed curettage.
  
  
  RESULTS
  After a chemical abortion, the pregnancy outcome had better ongoing pregnancy rates (24.7%) in comparison with the 17% achieved in the total IVF-ET cycles.
  
  
  CONCLUSIONS
  It is concluded that these two groups most probably have different pathophysiological backgrounds and concomitantly different future clinical impacts.
authors.affiliation: Sherman Fertility Institute, Department of Obstetrics-Gynecology, Golda Meir Medical Center (Hasharon Hospital), Petah-Tikva, Israel.
authors.forename: T
authors.initials: T
authors.lastname: Levy
authors.forename: D
authors.initials: D
authors.lastname: Dicker
authors.forename: J
authors.initials: J
authors.lastname: Ashkenazi
authors.forename: D
authors.initials: D
authors.lastname: Feldberg
authors.forename: M
authors.initials: M
authors.lastname: Shelef
authors.forename: J A
authors.initials: JA
authors.lastname: Goldman
mesh_terms: D000022:Abortion, Spontaneous / Q000097:blood*; D006063:Chorionic Gonadotropin / Q000097:blood; D018997:Chorionic Gonadotropin, beta Subunit, Human; D010064:Embryo Implantation; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007247:Infertility, Female / Q000628:therapy; D010446:Peptide Fragments / Q000097:blood; D011247:Pregnancy; D011379:Prognosis
chemical_list: D006063:Chorionic Gonadotropin; D018997:Chorionic Gonadotropin, beta Subunit, Human; D010446:Peptide Fragments