Laboratory techniques

_STP1240LAB

 

Spindle assessment (Oosight)

PICSI

Sequential embryo culture

EmbryoGen Medium with a Growth Factor

Morphokinetic embryo assessment

Slow freezing

Vitrification

Preimplantation Genetic Diagnosis (PGD)

Preimplantation Genetic Screening (PGS)

Natural Killer cells

Sperm Chromatin Structure Assay (SCSA)

Hyaluronic binding assay

 

Fertilisation

 

Spindle assessment (Oosight)

The meiotic spindle is a structure inside the egg, which helps organise the chromosomes.  By using special microscope optics and computer software we can visually assess the spindle and determine egg quality. It also helps us locate where the spindle is inside the egg so it is not damaged when we inject the sperm during ICSI.

 

PICSI

At WFC, we use a special PICSI dish to select functional sperm. The dish has small microscopic strips of Hyaluronan (HA) at the bottom. Hyaluronan is a natural substance, which is present around the oocyte. Mature sperm bind to HA. In normal ICSI we choose a sperm based on its looks and how it moves. In PICSI, we first choose a sperm that binds to the HA strips in the dish, showing that it is mature and of better quality. Then if it looks good and moves well, we use it to fertilise the egg.

 

Embryo culture

 

Sequential embryo culture

The egg, sperm and growing embryo are all different types of cells and require different nutrients and energy sources. In the WFC lab, we use sequential culture medium (fluid) to hold each cell type  in a fluid that is specifically designed to meet the cell’s needs, whether it be eggs, sperm or embryo.  Initially we use a special fertilisation medium when we mix the eggs and sperm. The growing embryo is then held in one type of fluid for the first 3 days and then transferred to a different fluid for the last 2 days.

 

EmbryoGen Medium with a Growth Factor

This medium was formulated as a result of the ground breaking research of our Scientific Director, Dr Cecilia Sjoblom. It is used for fertilisation, 3-day culture and embryo transfer. This very specific growth fluid contains Granulocyte Macrophage Stimulating Factor (GM-CSF). Inside the woman’s body GM-CSF supports the growth of the embryo and also helps with the communication between the mother and the embryo. Culturing embryos in GM-CSF can help overcome recurrent miscarriages.

 

Morphokinetic embryo assessment

Embryos are checked for development at key times during their growth. However with each assessment they are removed from the ideal environment within the carefully controlled incubators. In time-lapse monitoring of embryos, a camera is placed inside the incubator allowing the embryologists to see how the embryo is growing without removing it form the safe and warm incubator. This helps us assess development and identify embryo competence based on the time taken for the embryo to develop during each stage. This can help us choose the strongest embryo for transfer back to the mother.

 

Freezing of sperm, eggs and embryos (Cryo-preservation)

 

Slow freezing

Slow freezing is a well-established technique used for freezing sperm and embryos. It involves the use of specific solutions designed to protect the embryo and sperm during the slow controlled freezing process. Embryos are frozen at a rate of 0.3°C/ minute until -30°C, followed by very quick cooling down to -196°C. Once frozen the embryo is stored at -196°C.

At WFC we have been involved in developing a new revolutionising protocol for slow freezing. With this new approach, more than 95% of the frozen embryos survive and cleave after thawing.

Embryo slow freezing is used to freeze the embryos just after fertilisation in a cycle where there will not be an embryo transfer. Embryos are typically frozen in groups and when thawed, are cultured in the lab through normal embryo development and embryo selection prior to transfer.

 

Vitrification

Embryos can also be cooled using a method called Vitrification. This process also involves placing the embryo in specific solutions to protect the cells during the cooling process, and then cooling at 15,000-20,000°C / minute to allow the embryo to form a glass like state. Once cooled the embryo is stored at -196°C.

We can also cryo-preserve oocytes using the vitrification method. At WFC, we offer this service to women who must undergo cancer treatment that will damage the ovaries.

 

Genetic assessment of embryos

 

Preimplantation Genetic Diagnosis (PGD)

PGD is a treatment that may be recommended for couples whose children are at risk of inheriting a specific genetic disease or an abnormality associated with the chromosomes. To make sure that the embryos don’t carry the genetic disease, a few cells are taken out of the embryo and genetically tested. A healthy embryo will be transferred based on the result of the test.

 

Preimplantation Genetic Screening (PGS)

PGS  is similar to PGD, but instead of testing for a genetic disease or abnormality, the cells taken from the embryo are genetically screened to make sure that the embryo contains the right number of chromosomes (46).

 

Latest Diagnostic Technologies

 

Natural Killer cells

Natural Killer cells are the main type of immune cells in the body. Some women who have experienced recurrent miscarriage may have an elevated number of NK cells. There is some evidence to suggest that high levels of NK cells can impair the implantation of embryos to the uterus.

 

Sperm Chromatin Structure Assay (SCSA)

SCSA is a test that can measure the DNA fragmentation or damage within the sperm. This test may be useful in patients with repeated unsuccessful cycles or recurrent miscarriage. It is important to note that the sperm tested can not then be used for IVF or ICSI treatment – it is a diagnostic test only. However, the results may indicate whether other treatments such as PICSI could be of use.

 

Hyaluronic binding assay

This test assists embryologists in identifying the percentage of sperm in a solution that are mature and able to attach to the surface of the egg. Hyalronan is found in the complex cells that surround the human egg and during the last stages of sperm maturation, sperm should obtain the ability to bind to hyaluronan. This test gives an indication of the percentage of sperm present that are mature and have the ability to bind to hyaluronan.

Attend an information seminar
Westmead ButtonWestmead Doctor, IVF clinic
When: Wednesday, June 21st, 2017
Time: 5:30pm for 6:00pm start
Where: Westmead Fertility Centre
Cost: Free