This randomized trial we aim to compare the live birth rate of immediate versus delayed FET replacing a single blastocyst in the first FET of the first stimulated IVF cycle following. The hypothesis is that the live birth rate of the immediate FET is higher than the delayed FET replacing a single blastocyst in the first FET of the first stimulated IVF cycle following a freeze-all strategy. Women will undergo IVF/ICSI in the centre as clinically indicated. Standard ovarian stimulation with gonadotrophins in a Gonadotrophin releasing hormone (GnRH) antagonist protocol will be employed. Hormone replacement treatment (HRT) will be used in subsequent FET cycles. On Day 3 of the menstrual cycle, we will measure the anxiety levels using the Chinese State-Trait Anxiety Inventory and serum E2, cortisol levels will be checked on the same day. Recruited women having the first FET cycle following a freeze all strategy will be randomly assigned on the day of blastocyst(s) freezing according to a computer-generated randomization list into one of the following two groups.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
828
FET is performed in the first menstrual cycle following the stimulated IVF cycle
FET is performed in the second menstrual cycle following the stimulated IVF cycle
Shanghai JiAi Genetics & IVF Institute
Shanghai, Shanghai Municipality, China
live birth
deliveries ≥22 weeks gestation with heartbeat and breath
Time frame: 1 year after FET
positive hCG
serum β-hCG ≥10 mIU/mL
Time frame: 2 weeks after FET
clinical pregnancy
presence of intrauterine gestational sac by trans-vaginal ultrasound at 6 gestational weeks.
Time frame: 6 weeks' gestation
ongoing pregnancy
a viable pregnancy beyond 12 weeks' gestation
Time frame: 12 weeks' gestation
implantation rate
the number of gestational sacs per blastocyst transferred
Time frame: 6 weeks' gestation
miscarriage
a clinically recognized pregnancy loss before the 22 weeks of pregnancy
Time frame: 1 year after FET
multiple pregnancy
more than one intrauterine sacs on scanning
Time frame: multiple pregnancy beyond gestation 12 weeks
ectopic pregnancy
pregnancy outside the uterine cavity
Time frame: ectopic pregnancy during 12 weeks gestation
birthweight of newborns
the birth weight of newborns
Time frame: 1 year after FET
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.