The efficacy of tamoxifen during frozen embryo transfer cycles in women
with thin endometrium
Abstract
Objective: To investigate whether live birth rate (LBR) following
frozen-thawed embryo transfer in tamoxifen -stimulated cycles (T-FET)
differs from hormone replacement treatment FET (HRT- FET) in women with
thin endometrium. Design: Retrospective cohort study. Setting:
Tertiary-care academic medical center. Participant(s): A total of 671
patients with thin endometrium who fulfilled the inclusion criteria were
involved in the period from January 2016 till February 2019. Methods In
the group of T-FET, 20 mg TAM per day was giving from day 5 of the
menstrual cycle for 5 days. Day-3 ET was performed four days after
ovulation while blastocyst transfer was performed six days after
ovulation. In the group of HRT- FET, estradiol val¬erate was taken 6
mg/d from menstrual cycle day 2-3. 12 to 14 days later progesterone 40 -
60 mg/d was given. Embryo transfer was performed 3 or 5 days later for
day-3 embryos or blastocysts respectively. Main Outcome Measure(s): LBR
per embryo transfer was the primary outcome. The secondary end points
included ongoing and clinical pregnancy rate, cancellation rate,
endometrial thickness and pregnancy loss rate. Multivariable logistic
regression analysis was performed to adjust for potential confounders.
Result(s): LBR was significantly higher in T-FET group than HRT-FET
group. Moreover, the clinical and ongoing pregnancy rate also higher in
the T-FET group than in the HRT-FET group. Conclusion(s): In patients
with thin endometrium undergoing FET, tamoxifen use for endometrial
preparation was associated with higher LBR compared with HRT cycles.
Funding: No external funding was used.