Blastocyst culture and transfer

Blastocyst culture and transfer (BCT) is the most rigorous, biological and noninvasive scheme of selecting the healthier embryo(s) for transfer. Blastocyst is an embryonic stage achieved after 120-140 hrs post fertilization. Embryo at this stage, have outer shell, Zona Pellucida; a fluid filled cavity, Blatocoele; outer layer of cells, Trophectoderm; and inner cell mass, ICM. Prior to implantation, Zona Pellucida cracks open and Blastocyst hatches out. Trophectoderm makes contact with uterus forming Placenta and ICM forms the fetus.

It is a routine practice to transfer embryos of all stages (Day 1, 2, 3, and 5) into the recipient’s uterus. But embryo at blastocyst (Day 5/6) is the most suitable embryonic stages to be transferred into the uterus being its natural habitat.

Reducing the Chance of Multiple Births – Blastocyst Transfers

We want women who undergo in vitro fertilization (IVF) treatment at XPert Fertility Care (IVF XPERT) in Orange County and San Diego to conceive in a responsible manner, and then have healthy pregnancies.

It is well known that multiple gestational pregnancies (twins, triplets and beyond) are high-risk pregnancies. There are many complications associated with multiple pregnancies, most notably pre-term labor and pre-term delivery. Pregnancies with multiples also have a higher rate of birth defects. Aside from permanent life-long disabilities that can be associated with some premature births, the medical costs of these pregnancies can be high.

One way to reduce the risk of twins and avoid the risk of high order multiples (triplets and more) is to limit the number of embryos transferred back into the uterus. In the United States, there are no laws limiting the number of embryos that can be transferred, but only "guidelines", which unfortunately many IVF programs do not adhere to. Many IVF programs still transfer high numbers of embryos in order to compensate for poor pregnancy rates. By limiting the number of embryos transferred back into a woman’s uterus, Dr. Ho is able to maintain excellent pregnancy rates while reducing the risk of multiples, especially high order multiples.

Day-Five Blastocyst Transfers

To reduce the risk of multiples, Dr. Ho limits the number of embryos transferred during his in vitro fertilization cycles at XPert Fertility Care (IVF XPERT) in Orange County and San Diego by commonly performing day-five blastocyst transfers. During an IVF cycle, a woman is stimulated to produce multiple eggs. The eggs are retrieved and then fertilized with the partner’s sperm. At XPert Fertility Care, around 80 percent of the eggs retrieved become fertilized, forming embryos.

Once fertilized, the embryo must divide. Unhealthy embryos may stop dividing, divide very slowly, or fragment. By the third day after retrieval, a healthy embryo usually has around eight cells. Not every egg will fertilize, and not every embryo will continue to divide. By the fifth or sixth day after retrieval, if the embryo is healthy, it will become a blastocyst, which contains about 100 cells. By waiting until day five, we are able to put back the ‘best’ embryos with highest chance of implantation per embryo.

Following embryo culture to blastocyst stage, fewer but healthier embryos can be transferred. This approach results in higher pregnancy rates and greatly reduces the risks of pregnancy with multiple fetuses.

Traditionally, there are higher implantation rates per embryo with day-five blastocysts than with day-three embryos. If you place back embryos with a higher success for implanting, fewer embryos need to be transferred. This point has been supported by research done through our laboratory and in other programs as well.

To perform day-five embryo transfers and still maintain excellent pregnancy rates, the IVF laboratory services have to be extremely good. Some programs have attempted to do day-five transfers, but because of media issues, equipment, or technical skill, have stopped doing so and have gone back to performing day-three transfers.
 

Our laboratories have devised an indigenous protocol to offer blastocyst culture regardless of age of oocyte source and male factor infertility. We have track record of a successful blastocyst transfer program. Some of our recent publications on this subject are;

1)Blastocyst Formation after Intracytoplasmic Sperm Injection (ICSI) and Culture in Two Sequential Culture Media Preparation Differing with Respect to the Method of Protein Supplementation. Fertility and Sterility (2003) Vol 80: Sp.3

2)Developmental Competence of Blastocysts produced Following Intracytoplasmic Sperm Injection (ICSI). Fertility and Sterility (2002) Vol 76; No. 3S

Read more at home page XPert Fertility Care.

Tags: blastocyst