Pre-implantation genetic testing in ART: who will benefit and what is the evidence?

Pre-implantation genetic diagnosis for aneuploidy testing (PGD-A) is a tool to identify euploid embryos during IVF. The suggested populations of patients that can benefit from it are infertile women of advanced maternal age, with a history of recurrent miscarriages and/or IVF failures. However, a general consensus has not yet been reached.

Reduction of multiple pregnancies in the advanced maternal age population after implementation of an elective single embryo transfer policy coupled with enhanced embryo selection: pre- and post-intervention study.

Study Question: Is an elective single-embryo transfer (eSET) policy an efficient approach for women aged >35 years when embryo selection is enhanced via blastocyst culture and preimplantation genetic screening (PGS)?

Summary Answer: Elective SET coupled with enhanced embryo selection using PGS in women older than 35 years reduced the multiple pregnancy rates while maintaining the cumulative success rate of the IVF programme.

What Is Known Already: Multiple pregnancies mean an increased risk of premature birth and perinatal death and occur mainly in older patients when multiple embryos are transferred to increase the chance of pregnancy. A SET policy is usually recommended in cases of good prognosis patients, but no general consensus has been reached for SET application in the advanced maternal age (AMA) population, defined as women older than 35 years.

The worldwide frozen embryo reservoir: methodologies to achieve optimal results.

Cryopreservation of the human embryo has been successfully achieved at the zygote (day 1), cleavage (day 2/3), and blastocyst (day 5) stages; however, each stage presents specific advantages and disadvantages. During the past decades, two major methods have been applied: slow freezing (equilibrium procedure) and vitrification (nonequilibrium procedure). The overwhelming majority of published data prove that the latest vitrification methods induce less cellular trauma and are a more effective cryopreservation technique of human embryos than any other versions of slow freezing.

Embryo development of fresh 'versus' vitrified metaphase II oocytes after ICSI: a prospective randomized sibling-oocyte study.

Background: A successful oocyte cryopreservation programme is of utmost importance where a limited number of oocytes can be inseminated per cycle, to overcome legal and ethical issues related to embryo storage, for oocyte donation programmes and for fertility preservation (especially for cancer patients). Vitrification has been recently proposed as an effective procedure for this purpose.

Methods: In order to validate the effectiveness of oocyte vitrification a non-inferiority trial was started on sibling metaphase II (MII) oocytes.

Significance of metaphase II human oocyte morphology on ICSI outcome.

Objective: To evaluate the influence of specific oocyte morphologic features (morphotypes) on intracytoplasmic sperm injection (ICSI) outcome. The identification of oocyte quality markers is particularly important when a low number of oocytes can be used for IVF.

Design: Retrospective analysis.

Developmental potential of fully intact and partially damaged cryopreserved embryos after laser-assisted removal of necrotic blastomeres and post-thaw culture selection.

Objective: Partially damaged frozen and thawed embryos are currently considered to have a lower viability than intact ones. This study was undertaken to compare the performance of intact frozen and thawed embryos with that of partially damaged embryos after removal of the necrotic blastomeres.

Design: Observational clinical series.

Significance of morphological attributes of the early embryo.

There are many morphological transformations during development of human embryos that mainly involve phenomena that can be easily assessed in living embryos by simple non-invasive microscopical observation. A clear correlation between pronuclear morphology and the ability of the resulting embryo to continue developing and to implant has been described. There is also general agreement that a positive relationship exists between early embryo morphology and implantation rate.

Natural in vitro fertilization cycles.

Although the first in vitro fertilization (IVF) baby was born after a natural IVF cycle, very soon this procedure was almost abandoned mainly because of the very high cancellation rates, and controlled pharmacological ovarian hyperstimulation became the standard treatment in IVF cycles of normoresponder patients. However, in poor-responder patients, where only very few follicles can be recruited and very few oocytes, if any, can be retrieved after controlled ovarian hyperstimulation, natural IVF cycles may offer a comparable number of follicles, reduced costs, and less discomfort for the patients. In this group of patients, natural IVF cycle is a cost-effective approach.