Building a model to increase live birth rate through patient-specific optimization of embryo transfer day.
OBJECTIVE
Many practices are moving away from cleavage-stage transfer in favor of blastocyst transfer. The purpose of this study is to evaluate how the overall live birth rate for fresh IVF cycles may increase by optimizing the day of transfer for each patient.


METHODS
This is a retrospective cohort study of 1225 first fresh autologous IVF cycles performed between May 2012 and November 2013. Stepwise logistic regression was used to determine characteristics associated with live birth following cleavage-stage versus blastocyst transfer. The optimal transfer day (i.e., the day that maximized the odds of live birth) was determined for each patient, and the actual live birth rate was compared with the projected rate had each patient undergone transfer on her optimal day.


RESULTS
With transfer on the optimal day for each patient, the overall birth rate would have increased from its actual value of 34.8 % to a projected 43.0 %, a 24 % increase. The majority of this increase (21 %) was due to optimization of patients who underwent cleavage-stage transfer but had a higher projected birth rate from blastocyst transfer. These patients were older (37.8 versus 36.0 years, p < 0.01) and had more follicles ≥18 mm than patients who should have remained with a cleavage-stage transfer.


CONCLUSIONS
A model can be built enabling patient-specific identification of optimal transfer day; within this discovery cohort, such optimization was estimated to increase live birth following a fresh transfer by 24 %. This study suggests blastocyst transfer should be more widely offered; however, there remain patients for whom a cleavage-stage transfer may yield better outcomes.
Center for Infertility and Reproductive Surgery, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA. rhgoldman@partners.org.
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Goldman
Center for Infertility and Reproductive Surgery, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
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Kaser
Center for Infertility and Reproductive Surgery, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.|Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA.|Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
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Missmer
Center for Infertility and Reproductive Surgery, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
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Srouji
Center for Infertility and Reproductive Surgery, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.|Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, 02115, USA.
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Farland
Center for Infertility and Reproductive Surgery, Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
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Racowsky
D000328:Adult; D001755:Blastocyst / Q000166:cytology; D002970:Cleavage Stage, Ovum / Q000378:metabolism; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D050498:Live Birth / Q000235:genetics*; D011247:Pregnancy; D018873:Pregnancy Rate
Blastocyst transfer; Cleavage-stage transfer; Day 3 transfer; Day 5 transfer; Personalized medicine