Effect of coasting on the implantation potential of embryos transferred after cryopreservation and thawing.
OBJECTIVE
To examine the effect of withholding gonadotropins on the outcome of embryos after cryopreservation and thawing.


METHODS
Retrospective clinical evaluation of patients having cryopreserved-thawed ET trials with coasting during the corresponding ovarian stimulation cycle.


METHODS
Academic tertiary clinical care unit.


METHODS
Patients with cryopreserved embryos having coasting in their fresh IVF cycle and age-matched controls without coasting, both groups receiving the same stimulation protocol (long GnRH agonist plus recombinant FSH).


METHODS
All patients had a cycle in which embryos were transferred fresh and a cycle of thawing of cryopreserved embryos with the aim of transferring in a steroid-supplemented cycle.


METHODS
Embryo survival, implantation, and clinical pregnancy rates.


RESULTS
Post-thawing embryo survival (66.4% vs. 73%), implantation (12.3% vs. 13.0%), and clinical pregnancy rates (31.5% vs. 38.0%) were similar in study and control groups, respectively. Patients with coasting for > or =3 days had significantly lower post-thawing embryo survival rates compared with patients having shorter duration of coasting (<3 days) and controls. Implantation and pregnancy rates, however, were similar in the three groups.


CONCLUSIONS
Coasting did not seem to have a detrimental effect on oocyte and embryo quality because the implantation competence of transferred concept after cryopreservation and thawing was similar to that of controls. However, prolonged coasting (> or =3 days) had a subtle negative impact on the post-thaw survival rate.
Arslan
Murat
M
Department of Obstetrics and Gynecology, The Jones Institute for Reproductive Medicine, Eastern Virginia Medical School, Norfolk, Virginia, USA.
Bocca
Silvina
S
Jones
Estella
E
Mayer
Jacob
J
Stadtmauer
Laurel
L
Oehninger
Sergio
S
D000328:Adult; D015925:Cryopreservation / Q000379:methods* / Q000706:statistics & numerical data; D010064:Embryo Implantation / Q000187:drug effects / Q000502:physiology*; D004624:Embryo Transfer; D005260:Female; D006062:Gonadotropins / Q000008:administration & dosage; D006801:Humans; D011247:Pregnancy; D018873:Pregnancy Rate; D012189:Retrospective Studies; D013997:Time Factors
D006062:Gonadotropins