Experience with the elective transfer of two embryos under the conditions of the German embryo protection law: results of a retrospective data analysis of 2573 transfer cycles

Abstract

The German embryo protection law (Embryonenschutzgesetz, ESchG) does not allow embryo selection. Therefore, only as many oocytes at the pronuclear stage (PN), as are planned to be transferred, are allowed to be cultured. It is not known whether, under these conditions, it is possible to reduce the number of embryos for transfer without a corresponding reduction of the overall pregnancy rate (PR). We retrospectively analysed 2573 consecutive transfer cycles following either in-vitro fertilization (IVF) or IVF/intracytoplasmic sperm injection. Out of these cycles, 234, 329 and 792 were performed with one, two, and three embryos respectively, because only that number was available (non-elective transfer). Another 123 and 1095 transfer cycles were performed with two and three embryos, respectively, which were selected from a higher number of PN oocytes (elective transfer). The clinical ongoing PR were 3.9, 9.1 and 17.7% respectively for the groups with non-elective transfer of 1, 2 and 3 embryos, and 22.0 and 22.5% for the groups with elective transfers with two and three embryos, respectively. There was no statistically significant difference in PR between the two elective embryo transfer groups up to the age of 40 years. The multiple pregnancy rate was reduced by 7.9%. The reduction of the number of embryos transferred from three to two can be performed even under the conditions of the ESchG without an effect on the overall PR.

The combination of pronuclear and blastocyst morphology: a strong prognostic tool for implantation potential

“…Many studies have confirmed this importance of the cytoplasmic halo, showing an increased implantation rate when the cytoplasmic halo is present in zygotes [12,[17][18][19][20][21]. However, our study failed to find any such association, most likely because most of the embryos evaluated here showed a normal cytoplasmic halo pattern.…”

“…However, several authors have reported different results regarding the prognostic value of each PN feature. Some studies have reported a strong association between the PN orientation [9][10][11] or the number and distribution of NPB [12][13][14][15][16] and the implantation potential; others have suggested that an increased chance of implantation exists when the cytoplasmic halo is present in zygotes [2,[17][18][19][20][21].…”

Differences in the transcriptional profiles of human cumulus cells isolated from MI and MII oocytes of patients with polycystic ovary syndrome

“…Until now, the studies of gene expression profiles of CCs have reported a noninvasive method to predict oocyte and embryo competence (Assou et al 2010). Together with morphological evaluation, CC genes may serve as biomarkers of oocyte and embryo selection during the IVF process or might result in an oocyte selection tool for those who are obliged to select a limited number of oocytes for fertilization in countries where embryo cryopreservation is legally restricted (Ludwig et al 2000). Herein, for the first time, we have reported a significant alteration of gene expression in CCs isolated from mature oocytes and immature oocytes of PCOS patients under COS to identify molecular signatures in CCs that are associated with oocyte maturation or embryo development.…”

Affordable ART for developing countries: a cost benefit comparison of low dose stimulation versus high dose GnRH antagonist protocol

“…Several studies have shown this to be effective in reducing the risk of multi-fetal gestation [24]. Current consensus deemed a transfer of large numbers of embryos to increase "success rates" per IVF cycle is not justifiable.…”