Study design
This retrospective study was performed at the Reproductive Medical
Center of Anhui Provincial Hospital, involving women with thin
endometrium who undergoing their FET cycles during the period from
January 2016 till February 2019.
In our center, thin endometrium is diagnosed when the maximal
endometrial thickness(EMT) is ˂7 mm, dominant follicle are 18 mm in
diameter in nature cycle(NC), or after 12 to 16 days of estradiol (E2)
replacement(4–6 mg, Progynova; Bayer Schering Pharma, Roubaix, France).
Infertile women who met these criteria in their 1-2 previously FET
cycles were included in this study. All these women failed pregnancy
despite the treatment with oral and/or vaginal estrogen, sildenafil or
aspirin. Exclusion criteria were: uterine or endometrial abnormalities
other than thin endometrium; patients with repeated implantation
failures;<20 or >40 years of age at oocyte retrieval;
patients with multiple types of FET protocol following the same fresh
IVF/ICSI cycle. As there isn’t any consensus as to the ideal method of
endometrium preparation in patients with thin endometrium, endometrium
was prepared with TAM or HRT at the discretion of physicians and/or
patients’ preference. The study was approved by the institutional ethics
committee of Anhui Provincial Hospital.