Efficacy and safety of frozen-thawed embryo transfer in women aged 35 to 42 years from the PURSUE randomized clinical trial

Cumulative vital pregnancy and live-birth rates from fresh cycles and frozen-thawed embryo transfer were similar in in vitro fertilization patients aged 35–42 years treated with corifollitropin alfa and recombinant follicle stimulating hormone.

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Volume 106, Issue 2, Pages 300-305


Robert Boostanfar, M.D., Davis Gates, Ph.D., Yanfen Guan, M.S., Keith Gordon, Ph.D., Christine McCrary Sisk, B.S., Barbara J. Stegmann, M.D.



To examine the efficacy and safety of frozen-thawed embryo transfer (FTET) cycles with supernumerary embryos cryopreserved during a randomized clinical trial (PURSUE).


Follow-up clinical study.


In vitro fertilization (IVF) centers.


Infertile women 35 to 42 years of age.


In PURSUE, women were randomized to a single injection of 150 μg of corifollitropin alfa (n = 694) or daily 300 IU of recombinant follicle-stimulating hormone (recombinant FSH; n = 696) for the first 7 days of controlled ovarian stimulation (COS) in a gonadotropin-releasing hormone (GnRH) antagonist protocol.

Main Outcome Measure(s)

Cumulative vital pregnancy rate per-patient by treatment group, cumulative live-birth rate per-patient by treatment group, and occurrence of adverse events in (pregnant) women and their fetuses/infants and the incidence of congenital malformations in the infants.


Of the 1,390 treated women in PURSUE, 307 were enrolled in the FTET study. In PURSUE or a subsequent FTET cycle, the cumulative vital pregnancy rate (per patient) was 31.1% (95% confidence interval [CI], 27.7%; 34.7%) with corifollitropin alfa versus 33.0% (95% CI: 29.6%; 36.7%) with recombinant FSH; treatment difference, −1.8% (95% CI, −6.5%; 3.0%), and the cumulative live-birth rate (per patient) was 28.2% (95% CI, 24.9%; 31.8%) with corifollitropin alfa versus 29.5% (95% CI, 26.1%; 33.0%) with recombinant FSH; treatment difference, −1.2% (95% CI, −5.7%; 3.4%). There were no clinically relevant differences in safety outcomes collected from pregnant women or their infants after transfer of cryopreserved embryos obtained by treatment with corifollitropin alfa or recombinant FSH.


The cumulative vital pregnancy and live-birth rates (from fresh cycles and FTET) were similar in women treated with corifollitropin alfa and recombinant FSH. No new safety signals were detected in this follow-up FTET study.

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Fertility and Sterility

Editorial Office, American Society for Reproductive Medicine

Fertility and Sterility® is an international journal for obstetricians, gynecologists, reproductive endocrinologists, urologists, basic scientists and others who treat and investigate problems of infertility and human reproductive disorders. The journal publishes juried original scientific articles in clinical and laboratory research relevant to reproductive endocrinology, urology, andrology, physiology, immunology, genetics, contraception, and menopause. Fertility and Sterility® encourages and supports meaningful basic and clinical research, and facilitates and promotes excellence in professional education, in the field of reproductive medicine.