Benefits of Transferring Blastocysts Instead of Embryos for IVF
At First Fertility, we have offered fertility medicine to women who struggle with natural conception for many years. To continue delivering effective IVF treatments, we pay attention to all fertility developments, including the latest techniques, procedures, and medicines.
There have been many advances for us to track in the past several decades. However, the most intriguing developments have occurred in just the last several years.
Fertility specialists are constantly finding ways to increase fertility and pregnancy rates through IVF treatments. It now appears that these specialists have discovered a new method for helping women with successful pregnancies and births.
Using blastocysts instead of embryos may offer women a greater chance of a successful pregnancy.
Early IVF Treatments Focused on Quantity
In 1978, the first child was born through IVF. During the infancy of IVF treatments, specialists believed that the number of embryos was essential to improving fertility. IVF clinics focused on obtaining as many embryos as possible as quickly as they could. This often required the collection of embryos as soon as they are available.
These early IVF treatments used the scientific research that was available at the time. The IVF specialists were correct to assume that the quantity of embryos is important. However, quality is even more important. The latest research indicates that transferring a blastocyst instead of an embryo may help certain women increase the odds of getting pregnant.
What is a Blastocyst?
With the early IVF treatments, the embryo was inserted into the uterus two to three days after the fertilization of the egg. Five days after fertilization, the embryo reaches the blastocyst stage.
The primary difference between a blastocyst and an embryo is age is that blastocysts are basically embryos that are several days further in their development.
Advantages of Transferring a Blastocyst
IVF specialists used to believe that it was necessary to insert the embryo as soon after the fertilization as possible. They would also insert multiple embryos, hoping that at least one of the embryos will be healthy and result in a successful pregnancy and live birth.
There are several reasons that blastocysts may offer a great chance of getting pregnant. As blastocysts have five days to develop, there is a greater chance of obtaining quality blastocyst embryos for implantation.
As it takes five days for an embryo to develop and reach the blastocyst stage, it is difficult to determine their quality when they are transferred after just two or three days. Waiting for the embryos to develop before inserting them into the uterus allows the IVF specialists at First Fertility Bangkok to evaluate the quality of the embryos.
Waiting an extra two or three days to transfer the embryos also gives the uterus more time to prepare for the fertilization process. With natural conception, the embryo does not pass from your fallopian tubes to the uterus within the first two to three days. Introducing the blastocyst to the uterus at a later stage mirrors the natural process.
The uterus lining also has more time to reach the preferred thickness. Specialists typically hope that the lining reaches a thickness of 10 to 12 millimetres prior to transferring the embryo. Waiting for the lining to thicken increases the chance of successful implantation and pregnancy.
Allowing the embryo to develop before transferring also gives doctors more time to tell if there are any abnormalities or defects. For women over a certain age, abnormal eggs are common. In fact, for women over the age of 40, nearly 75% of eggs contain abnormalities. Using blastocysts, women may not need to transfer as many embryos to increase the chance of pregnancy.
Blastocysts also allow doctors to conduct pre-implantation genetic diagnoses. Diagnosing the embryos gives doctors the chance to detect DNA abnormalities and determine the gender.
While there are many advantages to transferring blastocysts, it is important for patients to understand that this IVF procedure may not provide the best solution for every patient.
At First Fertility, each patient requires an individualized approach. Some embryos will not survive to the 5th day. If possible, it is typically better to insert younger embryos than inserting none.
You May Not Require as Many Blastocysts
As mentioned, clinics used to transfer multiple embryos to increase the chance of pregnancy. At First Fertility, patients have the option of transferring multiple blastocysts. While you may not require as many blastocysts, evidence suggests that the chance of successful pregnancy increases when more embryos get transferred.
In the UK, the Human Fertilization and Embryology Authority (HFEA) aims to reduce the occurrence of multiple pregnancies. Inserting multiple embryos increases the chances of carrying more than one baby. For these reasons, clinics in the UK only insert one embryo for most IVF procedures. UK fertility clinics are required to try to limit multiple births.
At First Fertility, we do not need to comply with these same regulations. This allows us to transfer four embryos. With our IVF treatments, one to four blastocysts can be inserted to help increase your odds. Our main goal is to help our patients successfully get pregnant and deliver a healthy baby.
Twins and triplets are still better than not getting pregnant. However, we do try to limit the chance that you may have twins or triplets. In many cases, a single pregnancy may be healthier for both the mom and the baby.
Last Thoughts on Transferring Blastocysts
Transferring blastocysts provides doctors with more control over the IVF process. Using embryos that have reached the blastocyst stage gives us the ability to evaluate the quality of the blastocyst embryos before transferring them into your uterus.
Using blastocysts, we can predict with a greater accuracy whether the embryos are healthy enough to help achieve pregnancy and live birth. Waiting five days also gives the uterus more time to recover after receiving the hormone injections that are needed before harvesting the eggs.
Keep in mind that blastocysts may result in fewer embryos available for freezing. However, blastocysts still provide a more effective option for many women. While choosing between blastocysts and embryos can be challenging, the team at First Fertility can help determine the best option based on your health, the health of your eggs, and your personal preferences.