Casting for determinants of blastocyst yield and of rates of implantation and of pregnancy after blastocyst transfers.

Objective: To identify determinants of blastocyst yield, implantation rate, and pregnancy outcome.

Design: Retrospective analysis of outcomes of 1,653 cycles of IVF.

Setting: Private infertility clinic.

Age thresholds for changes in semen parameters in men.

Objective: To determine whether age thresholds for elements of semen quality exist.

Design: Retrospective analysis (covariance and point-change analysis) of results of 4,822 semen analyses and 259 fluorescence in situ hybridization (FISH) analyses.

Setting: Reference laboratory within an infertility clinic.

The rate at which serum total beta-subunit human chorionic gonadotropin increases after embryo transfer is a predictor of the viability of pregnancy and an identifier of determinants of pregnancy.

Objective: To determine whether elements of treatment associated with faster doubling times of total beta-hCG in serum (beta-t2) in pregnant patients are also associated with a higher likelihood of pregnancy in all patients.

Design: Retrospective analysis of beta-t2 values, elements of ovarian stimulation (COH), and outcomes.

Setting: Private assisted reproductive technology (ART) center.

Embryo fragmentation as a determinant of blastocyst development in vitro and pregnancy outcomes following embryo transfer.

Objective(s): To determine how the type of embryo fragmentation on day 3 affects progression of human embryos to blastocyst and pregnancy rates following embryo transfer.

Study Design: Retrospective analysis of all in vitro fertilization cycles in patients < or =40 years of age or younger from January 2002 through December 2003, during which time surplus day 3 embryos were transferred to blastocyst medium for extended culture. All embryos (4 cells or more) not suitable for transfer or freezing 72 hours following in vitro fertilization were placed into microdroplets (60 microL) of blastocyst medium and cultured for an additional 48 hours to assess blastocyst formation.

Potential factors affecting embryo survival and clinical outcome with cryopreserved pronuclear human embryos.

Objective: This study was undertaken to determine whether the method of fertilization has a significant impact on survival and/or clinical pregnancy rates of cryopreserved human pronuclear (2PN) stage embryos.

Design: A retrospective analysis of cryosurvival and clinical pregnancy rates after thawing of 2PN stage embryos from January 2000 through December 2002 in a private Assisted Reproductive Technology (ART) center.

Material And Methods: A total of 1408 human 2PN embryos were cryopreserved using a Planer Kryo 10 Series III freezing unit (TS Scientific, Perkasie, Pa) after dehydration/equilibration through Propanediol (Sigma Chemical, St.