Objective To compare human chorionic gonadotropin (HCG)-administered natural cycle with spontaneous ovulatory cycle in patients undergoing frozen-thawed embryo transfer (FTET) in natural cycles. Methods In this retrospective cohort study, we analyzed the clinical outcome of a total of 166 consecutive FTET cycles that were performed in either natural cycle controlled by HCG for ovulation trigg...

Co-culture of human embryos (n = 384 cycles) to the blastocyst stage using Vero cell monolayers was carried out between August 1995 and December 1997. A total of 2868 zygotes were co-cultured and 1027 embryos reached the blastocyst stage (blastocyst formation rate 35.8%). The blastocysts were frozen in 43.7% of patients. A mean of 1.8 blastocysts was transferred per patient and 95 pregnancies w...

BACKGROUND It has been claimed that the risks to the child resulting from vitrification as compared with the slow-freezing technique, may be higher owing to the high concentrations of potentially toxic cryoprotectants. We therefore retrospectively compared the obstetric and neonatal outcomes in a cohort of children born after transfer of vitrified blastocysts, fresh blastocysts and slow-frozen ...

OBJECTIVE To study the effect of freeze-thaw on embryos derived from intracytoplasmic sperm injection (ICSI) using surgically retrieved and ejaculated spermatozoa. DESIGN Retrospective study. SETTING Private IVF center. PATIENT(S) Three hundred eighty-three patients undergoing frozen-thawed ET cycles. INTERVENTION(S) Testicular sperm aspiration (TESA) or percutaneous epididymal sperm as...

Empty follicle syndrome (EFS) is a rare condition characterized by failure to obtain oocytes despite repeated meticulous aspiration from normally growing ovarian follicles during in vitro fertilization (IVF) cycles. Here in we report two cases of empty follicle syndrome after gonadotropin releasing hormone agonist (GnRHa) triggering for final oocyte maturation due to ovarian hyperstimulation sy...

Sir, We read with great interest the study entitled ‘Transfer of fresh or frozen embryos: a randomized controlled trial’ (Wong et al., 2021), recently accepted for publication in Human Reproduction. In this well-designed (n = 204), Wong al. tried to address question whether elective ‘embryo freeze-all strategy’ (i.e. transfer frozen-thawed blastocysts [FETs]) was superior ‘conventional and FETs...