The prognostic value and significance of preclinical abortions in in vitro fertilization-embryo transfer programs.
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.
Levy
T
T
Sherman Fertility Institute, Department of Obstetrics-Gynecology, Golda Meir Medical Center (Hasharon Hospital), Petah-Tikva, Israel.
Dicker
D
D
Ashkenazi
J
J
Feldberg
D
D
Shelef
M
M
Goldman
J A
JA
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
D006063:Chorionic Gonadotropin; D018997:Chorionic Gonadotropin, beta Subunit, Human; D010446:Peptide Fragments