Giving embryo transfer the best chance of success

One of the most critical steps in the IVF process is ‘embryo transfer’ – this is when a fertilised egg (now called an embryo) is transferred into your womb (uterus). If this embryo successfully implants in the wall of your womb and begins to grow, a pregnancy results.

As science and technology have progressed, so too have the techniques we can use during embryo transfer to increase the chances of a successful pregnancy. Below we outline the specific techniques we use at Newlife IVF to facilitate success during this part of the IVF cycle.

1. Growing and selecting the best embryo

During IVF, your eggs, sperm, and later embryos, are kept in an incubator. An incubator is a bit like an oven. It maintains a stable environment (including an even temperature), which helps the embryos to grow and develop.

As your embryos grow in the incubator, we observe them very carefully. In the past, this meant repeatedly opening the incubator at regular intervals to get ‘snap-shots’ of their growth – but this also meant that we were constantly disturbing the embryos as they developed.

More recently, advances in technology have led to the development of a special type of incubator called the EmbryoScope time-lapse system. The EmbryoScope has a built-in camera and high-powered microscope, which enables us to automatically capture images of your growing embryos every 10 minutes. Essentially, this means we no longer have to keep opening the ‘oven door’, allowing us to closely monitor the development of your embryos without disturbing them.

The benefits of this are two-fold:

  1. We ensure a stable environment for embryo growth, which contributes to embryo quality, and;
  2. We get a more complete picture of embryo quality, enabling us to select the best embryo for transfer.

In most cases, we will select embryos that are at the ‘blastocyst’ stage of development (around 5 days old). This is roughly the same time that an embryo would normally be in the uterus after a natural conception. Transferring the embryo at this stage (instead of the earlier ‘cleavage’ stage around day 2–4) means the embryo is more mature and has already demonstrated its potential for strong growth. Blastocyst transfer may also reduce the risk of the embryo being expelled from the mother due to altered levels of hormones that can occur after the egg freezing process.

The other benefit of waiting until embryos have reached the day 5–6 cell stage is that we can test them for chromosomal or specific genetic defects prior to transfer using preimplantation genetic testing or non-invasive chromosomal screening. These tests are not recommended for everybody but may be advised if you are older, have experienced recurrent miscarriage or multiple failed IVF cycles. In this case, our aim is to screen out any embryos with genetic anomalies that are unlikely to result in an ongoing healthy pregnancy, so that the embryo with the best potential for development can be placed in the womb.

At Newlife IVF, we routinely use the EmbryoScope time-lapse system for all IVF procedures, as part of our standard of care. Patients do not pay more for this technology. It is included in our standard cycle fees.

2. Deciding the optimum number of embryos to transfer

In the past, it was common practice to place two or more embryos in the womb at the same time, with the aim of increasing the chance of success. However, this practice has fallen out of favour due to the likelihood of a multiple pregnancy (e.g. twins or triplets). While this may seem like an ideal way to complete your family in one go, multiple pregnancies actually carry an increased risk of miscarriage and other complications. For this reason, our preferred practice at Newlife IVF is to transfer a single, high-quality embryo. That’s why we put a lot of effort into selecting the right embryo to transfer.

3. Guiding and protecting the embryo during transfer

The way an embryo is transferred into the womb is also critical to its success. We use a thin, flexible tube, called a soft catheter, to guide the embryo and protect it during its journey from the incubator to the womb.

For the best possible odds of an ongoing pregnancy, the embryo also needs to be placed in the correct location within the womb. Every woman’s uterus can vary in shape, so we may sometimes conduct a ‘mock embryo transfer’ before the actual procedure to determine the location and transfer technique that will give the best chance of success.

During the transfer, we use ultrasound imaging (the same technology used to view a baby in the womb) to provide us with real-time information about the catheter’s location, enabling highly accurate placement of the embryo in the womb.

4. Helping the embryo to implant in the wall of the womb

Once the embryo has been placed in your womb, it must attach to the wall of the uterus in a process called implantation before it becomes a viable pregnancy.

To improve the likelihood that the embryo implants, we place the embryo in a special substance called EmbryoGlue before we transfer it. EmbryoGlue was developed following the discovery that certain compounds that occur naturally in the body may help the embryo to attach to the wall of the uterus.

A major component of EmbryoGlue, hyaluronan, is normally found in the uterus and has chemical properties that increase cell viscosity. This is thought to assist the embryo to attach to the wall of the womb, increasing the chances of implantation and a successful pregnancy.

We aim to optimise every step in the treatment cycle

By employing advanced scientific techniques like these at every step in the IVF cycle, we aim to give our patients a better chance of achieving a successful pregnancy sooner.

If you would like advice specific to your circumstances or a second opinion, you can make an appointment with one of our fertility specialists by calling Newlife IVF on (03) 8080 8933 or by booking online. This appointment does not need to be about IVF specifically – there are many different ways we can assist with conception depending on your fertility needs.

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