Assisted Reproductive Technology: How Microscopy Can Help Families Grow

Dr. Liow Swee Lian is one of the pioneers in the field of Assisted Reproductive Technology (ART) in Singapore. He was part of the team at the Department of Obstetrics and Gynaecology at the National University of Singapore in 1990, immersed in a pioneering scientific research environment. He and his team focus on advanced fertility treatments such as Intracytoplasmic Sperm Injection (ICSI), and comprehensive embryo freezing techniques, dedicated to helping couples overcome infertility.

For men with severely reduced levels of sperm morphology (size and shape) or with mid- or high-range DNA damaged sperm, there is an increased risk of miscarriage and reduced clinical pregnancy rates – even with ICSI treatment. This is where Intracytoplasmic Morphologically Selected Sperm Injection (IMSI) treatment is used. IMSI allows the laboratory to enlarge the images of sperm to over 1,200 times its actual magnification, allowing for more precise selection of sperm based on morphology. By comparison, standard ICSI treatment only offers 200 to 400 times the magnification of sperm.

The IVF laboratory at VFCS meets stringent requirements, ensuring that every biological material – from sperm to embryo – is treated with the utmost care and attention.

IVF begins with a detailed sperm analysis and oocyte preparation, followed by the delicate fertilization process. Microscopes help identify the best quality sperm and oocyte combinations for fertilization with the aim to maximize the chances of successful embryo development.
 

At VFCS, the IVF process is a carefully orchestrated sequence of steps, each requiring meticulous attention to detail. It begins in the andrology lab, where the patient sperm quality is routinely analyzed before any treatment option is proposed. If IVF is considered as the choice of treatment, the next step involves choosing the healthiest sperm for fertilization with the oocyte retrieval and preparation done in parallel.

In the embryology lab, oocytes are assessed for quality, with embryologists identifying the most viable candidates for fertilization with the help of inverted light microscopes using different contrasting techniques. The tools allow the embryologists to see detailed structures, such as sperm heads and the meiotic spindle of oocytes. This helps them to make informed decisions about selecting the healthiest cells.
Sperm samples and oocytes are tagged with a matching radio frequency ID tag to avoid sample mismatches.

A key moment in the process is the fertilization itself: a sperm is injected directly into the oocyte in a highly controlled environment, using the high magnification and Hoffman modulation contrast of the widefield microscope instrumentation. This minimizes the risk of damaging biological material during the procedure. Then, a sensitive period of embryo culture follows, during which the fertilized oocytes develop under optimal conditions. Finally, the embryos are monitored as they grow. When the embryos reach the blastocyst stage, they are frozen and stored in liquid nitrogen until the patient’s embryo transfer.

VFCS offers to freeze the embryos at the optimal stage of development, to be stored until the patient is ready for transfer. This approach minimizes stress to the embryos and improves pregnancy outcomes.
The blastocyst with the highest developmental potential is selected for transfer.
This comprehensive process is supported by advanced imaging techniques to ensure that each embryo selected for implantation has the greatest possible chance of resulting in a successful pregnancy.