Insemination, Fertilization and Embryo Assessment

Insemination

For those using their partner’s sperm, a semen sample is usually collected 1-3 hours following egg retrieval. Once the embryologist has assessed egg maturity, the partner providing sperm will be given specific instructions as to the timing of collection. Samples may be produced on site at the Regional Fertility Program in the Diagnostic Semen Laboratory or at home if previous arrangements are made. The partner providing sperm must present government issued identification(with photo and signature) at the time of collection. The sample cannot be accepted without identification.

Sometimes in stressful situations some individuals providing sperm may find it difficult to produce a semen sample. If there is any possibility that the partner providing sperm will be unable to provide a sample to inseminate the eggs on the day of the egg retrieval it is highly advisable that a sperm sample be frozen well in advance of starting the IVF cycle. There is a charge for freezing and storing the sperm sample but is well worthwhile to prevent this unfortunate situation. The eggs have to be fertilized shortly after retrieval and if there is no sperm sample available the eggs will have to be frozen. This results in extra charges and a reduced chance of having a pregnancy from that IVF cycle. If there is even a remote possibility that the partner may experience difficulty producing a semen sample, it is important that you speak with your fertility physician well in advance of the IVF cycle so arrangements can be made to freeze a semen sample as a backup.

Once the eggs and sperm have been collected, either conventional or ICSI insemination is carried out. The determination of suitability of conventional insemination or ICSI will be decided in consultation with your physician prior to the procedure. In conventional insemination, several thousand sperm are placed with each egg in a Petri dish containing nutrient media. These dishes are then incubated for approximately 16 hours (overnight) and assessed the following morning for fertilization.

Fertilization Check

The morning following egg retrieval, the embryologist will assess the number and quality of fertilized eggs which are now called zygotes. The embryologist will speak with each couple personally to discuss the results. If using partner sperm, this partner must remain in Calgary until fertilization is confirmed. In cases of failed or poor fertilization, a second semen sample may be required the morning following retrieval.

Embryo Assessment and Development

Each day the embryologist will assess the quality of the embryos by examining factors such as:

cell division number
timing of division
cell size
cellular components
spatial arrangement, and
degree of fragmentation, if any.

Poor quality embryos include those with improper cell division, high degree of fragmentation, or intracellular inclusions such as vacuoles. Laser assisted embryo hatching may be recommended if there is poor embryo quality or if the embryo shell (zona pellucida) is excessively thick. By the third day after egg retrieval, a healthy embryo should have approximately eight cells, and by the fifth day after egg retrieval it is termed a blastocyst, which contains over 100 cells.