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A retrospective cross-sectional study: fresh cycle endometrial thickness is a sensitive predictor of inadequate endometrial thickness in frozen embryo transfer cycles

Patricia T Jimenez1*, Samantha B Schon2, Randall R Odem2, Valerie S Ratts2 and Emily S Jungheim2

Author Affiliations

1 Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX, USA

2 Department of Obstetrics and Gynecology, Washington University School of Medicine, Washington, DC, USA

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Reproductive Biology and Endocrinology 2013, 11:35  doi:10.1186/1477-7827-11-35

Published: 10 May 2013



The purpose of this study is to assess predictors of inadequate endometrial cavity thickness (ECT), defined as < 8 mm, in frozen embryo transfer (FET) cycles.


This is a retrospective cross-sectional study at an academic fertility center including 274 women who underwent their first endometrial preparation with estradiol for autologous FET in our center from 2001-2009. Multivariable logistic regression was performed to determine predictors of inadequate endometrial development in FET cycles.


Neither age nor duration of estrogen supplementation were associated with FET endometrial thickness. Lower body mass index, nulliparity, previous operative hysteroscopy and thinner fresh cycle endometrial lining were associated with inadequate endometrial thickness in FET cycles. A maximum thickness of 11.5 mm in a fresh cycle was 80% sensitive and 70% specific for inadequate frozen cycle thickness.


Previous fresh cycle endometrial cavity thickness is associated with subsequent FET cycle endometrial cavity thickness. Women with a fresh cycle thickness of 11.5 mm or less may require additional intervention to achieve adequate endometrial thickness in preparation for a frozen cycle.

Endometrial thickness; Frozen embryo transfer; Estrogen supplementation