MESA

These procedures are offered to couples in cases where the male has no sperm present in the ejaculate. They are used in conjunction with an ICSI procedure. (For more information please see the ICSI section).

In some semen samples there may be no sperm present in the ejaculate. There can be a variety of reasons for an absence of sperm known as Azoospermia.

There may be a blockage of the tubules that carry the sperm from the testicles to the penis.
The passages themselves may not have developed so sperm cannot be transported. This is known as absence of the vas deferens. If the latter is diagnosed then genetic counselling may be offered as there can be a high risk of males with this diagnosis who are identified as carriers of the cystic fibrosis gene.
In some cases sperm may be produced but in low numbers, and therefore not seen in the semen sample.
The male may have had a vasectomy performed which means that the passages that carry the sperm have been severed.

PESA- Percutaneous Epididymal Sperm Aspiration

This procedure may be performed under GA or local anaesthetic with sedation. A fine needle is passed into the epididymis to extract fluid. This is then checked in the laboratory by the embryologist for sperm.