Additional embryological techniques


Vitrification (literally meaning “turn to glass”) is a rapid method which may be used to freeze eggs and embryos and is associated with higher success rates than the older and slower freezing methods.
Freezing may be useful in the following circumstances

  • where excess spare embryos are created in a treatment cycle which are of good quality. Approximately 80% of frozen embryos will survive the freeze/thaw process
  • where gametes (eggs or sperm) are frozen to preserve fertility

Blastocyst transfer

At IVF Hammersmith/BP we offer embryo transfer 7 days a week. Embryos may be transferred anytime between day 2 and day 5 of their development. Blastocyst transfer is a selection tool which helps us to identify the strongest embryo/s for transfer and is a good technique to use where 3-4 good quality embryos have developed by day 3.

Assisted hatching

Very small holes can be made in the outer coating of an embryo with a laser to encourage hatching of embryos. We may suggest using the process with multiple failed cycles of treatment or in the case of frozen embryo transfer where the outer coating may become tougher.

Embryo Glue™

Hyaluranon is a naturally occurring substance present in follicles, tubes and cavity of the womb. Its effect is to make the fluid in these areas more viscous (sticky) and to encourage implantation of embryos.


Hyaluranon may also help to isolate mature sperm for use in ICSI (intracytoplasmic sperm injection) cycles helping to increase fertilisation rates


The embryoscope allows time-lapsed photography of embryos whilst they remain at all times within the incubator. This enables us to assess an embryos development in far more detail and help us to identify more accurately pregnancy competent embryos.

Comprehensive chromosomal testing

New techniques allow us to examine all of the chromosomes and to see if an embryo lacks or has additional chromosomes, a condition called aneuploidy. This technique may be helpful in those patients that have had multiple IVF failures or for older women who produce more genetically abnormal eggs. More recent research suggests that younger women may also produce large numbers of abnormal eggs during IVF treatment and may also benefit from this procedure by achieving higher than average success rates and limiting multiple pregnancies.