Aim Several studies have indicated that the cause of the increased birthweight of frozen-thawed embryos was associated with assisted reproductive technology (ART) procedures, such as cryopreservation. In the present study, the mean birthweight of singletons was compared between the ovulatory and hormone replacement therapy (HRT) cycles in order to investigate the primary factor that leads to hi...

OBJECTIVE It is well known that fresh blastocyst transfer results in better pregnancy outcomes with a smaller number of transferred embryos compared with cleavage stage embryo transfer. However, in terms of frozen-thawed blastocyst transfer, only a few studies are available. We aimed to evaluate clinical outcomes of frozen-thawed embryo transfer (FET) with blastocysts. METHODS Retrospective a...

Recent dramatic increases in success rates with frozen-thawed embryo transfer (FET) are encouraging, as are numerous findings of several reduced risks with FET when compared with fresh transfer. These reduced risks include low birth weight and prematurity, among others. However, FET is also associated with increased risks of macrosomia and large for gestational age. There have been reports of g...

BACKGROUND Assisted hatching (AH) in fresh embryo transfer (ET) could be associated with increased implantation rates. However, very few prospective randomized studies have specifically addressed the issue of AH during frozen-thawed embryo transfers (FET) cycles, those that have reported controversial results. The aim of this study was to evaluate the benefit of an enzymatic zona pellucida trea...

In order to reduce the chance of multiple pregnancy during in-vitro fertilisation (IVF)– embryo transfer treatment, there is an increasing trend towards transferring a lower number of embryos. Surplus good-quality embryos are then transferred in frozen-thawed embryo transfer (FET) cycles. The first pregnancy after FET was reported in 1983.1 It has been estimated that in IVF programmes in which ...

background: the use of assisted reproductive technology (art) is increasing in the world. the rate, efficacy and safety of art are very different among countries. there is an increase in the use of intra cytoplasmic sperm injection (icsi), single fresh embryo transfer (et) and frozen-thawed embryo transfer (fet). objective: the objective of this study was to compare pregnancy rate in fresh et a...

The implantation of embryo depends on the quality of the embryo and the receptivity of the endometrium. While the factors affecting embryo quality were optimized, the implantation rates did not reach the desirable levels. This directs the blaming for endometrial receptivity which already has been affected by supra-physiological levels of hormone, namely estradiol, in controlled ovarian hypersti...

background: natural endometrium in frozen-thawed embryo transfer (fet) may have some benefits upon implantation in patients with repeated implantation failure (rif). it might be due to possible differences between natural and stimulated endometrial growth factors and cytokins secretions. objective: the objective of this study was to compare the pregnancy rate of fet on modified natural cycle ve...

STUDY QUESTION Does uterine peristalsis influence the chance of clinical pregnancy in an embryo transfer cycle? SUMMARY ANSWER The uterine peristaltic wave frequency before embryo transfer is inversely related to the clinical pregnancy rates in fresh and frozen-thawed embryo transfer cycles. WHAT IS KNOWN ALREADY Uterine peristalsis participates in regulating fluid migration after mock embr...

BACKGROUND Assisted hatching (AH) in fresh embryo transfer (ET) cycles increases the implantation and pregnancy rates, especially in women with a poor prognosis, repeated implantation failures and in older women. Little information exists in the literature regarding the role of AH in frozen-thawed embryo transfer (FET) cycles. METHODS Embryos were cryopreserved at the cleavage stage. On the d...