Understanding Blastocyst: Development, Importance, and IVF Role

The term 'Blastocyst' refers to the human embryo 5-6 days after fertilisation. It is the stage of development that the embryo must reach before it can implant in the uterus.

The structure of the blastocyst is complicated than the earlier embryo stages because as the cells keep on increasing in number, they become organised into 2 types, the trophectoderm whose main role is in the implantation into the uterine lining and the inner cell mass which will form the foetus.

As a lot of embryos are destined to arrest at early stages hence extended culture of embryos till the blastocyst stage will allow the embryologists to identify the group of embryos that are capable to implant in the uterus.

Blastocyst Embryo Transfer

It is one of the techniques that offer a higher IVF success rate. IVF treatment, combined with advanced fertility techniques, has made it possible for more couples to experience the joys of parenthood.

With blastocyst, the probability of getting pregnant is substantially higher. New fertility techniques aim at helping couples to overcome fertility complications. These techniques aim at simplifying and speeding up the treatment procedure.

IVF is an assisted reproductive treatment available for couples facing fertility issues. Doctors suggest fertility check if a couple has not conceived within 1 year of having unprotected sex.

When to Go for Blastocyst Embryo Transfer

Some couple prefers to continue trying for a year or two before visiting a doctor. If the couple is above the age of 35, it is advisable not to delay getting medical help. As per the current statistic, 1 in every 5 couples needs some kind of fertility assistance to start a family.

At the onset of fertility treatment, every couple is apprehensive. They meet with the doctor, not knowing what to expect. We are unlike a hospital and want our visitors to feel comfortable. IVF has become popular as the most successful fertility treatment worldwide. For many couples, this is their only hope for a baby.

IVF Treatment With Blastocyst

The IVF fertility treatment is a procedure in which the female eggs and male sperm are taken from both partners and fertilised in a lab. The egg that gets fertilised is known as an embryo. During IVF treatment, several embryos are created in the lab.

All the embryos are kept in an incubator, and their growth and progress monitored. During this stage, embryo splitting begins to take place. By the third day, the embryos are 8 cell structures. In a regular IVF transfer, the 3rd-day embryo is transferred to the female partner's uterus.

Blastocyst culturing is a technique in which the embryo is cultured in the lab for 5 or 6 days. After 5 days the embryo reaches the blastocyst stage. After blastocyst formation, the embryo is a 200 or more-cell structure and begins a rapid cleavage (cell division). The embryo begins to develop and grow at a fast pace.

Blastocyst Transfer Procedure

• Timing of Transfer: The blastocyst transfer for IVF treatment takes place on the 5th or 6th day after the egg retrieval. Due to the high success rate with the blastocyst, only one or two embryos are transferred to the uterus.
• Embryos Selection: The blastocyst transfer begins with the selection of the best embryos. This selection is based on the development of the embryo over the previous days. The cleavage pattern also helps to determine the quality of the embryo.
• Quality Assessment: On the 6th day, all the embryos may look good. However, some may have had abnormal cell division. These embryos are put aside and labelled as poor quality.
• Procedure: The blastocyst embryo transfer is a quick and simple procedure. After the blastocyst is placed in the uterus, the next stage is blastocyst implantation. This defines the success of the treatment.
• Implantation Stage: The blastocyst is ready to implant soon after the transfer. The endometrial lining is at the most receptive stage, and the blastocyst begins to implant almost immediately.
• Hatching and Attachment: The blastocyst begins to hatch and attach itself to the inner uterine wall. In some cases, the embryo starts hatching even before the transfer procedure. This allows the embryologist to monitor the hatching of the embryo from the zona pellucida, which is the protective outer covering of the embryo.

When is Blastocyst Recommended?

There are several cases in which we recommends blastocyst to patients. This advanced technique is very helpful for couples who have undergone multiple IVF cycle failure. A couple who have experienced at least 3 IVF cycle failures are advised to try IVF with blastocyst.

Blastocyst is also advisable for women who are older than 37 years. Women who have been diagnosed with a depleting ovarian reserve are also advised IVF with blastocyst.

Why Blastocyst?

In a natural conception after fertilisation, the embryo remains in the fallopian tubes for a few days. By the time the embryo reaches the uterus, it is in the blastocyst stage. Hence, culturing an embryo to a blastocyst stage imitates the natural process more closely, thereby assuring a higher chance of implantation.

Many embryos arrest before day 5. When the embryo is cultured to a blastocyst, the probability of selecting the best embryos for the IVF transfer is much higher. By this stage, the embryo which was not meant to make it have already arrested and only the better embryos remain. The risk of multiple births is also reduced with a blastocyst transfer.

Frequently Asked Questions