ICSI (intracytoplasmic sperm injection) Treatment for Male Factor Infertility
ICSI (intracytoplasmic sperm injection) is primarily used to treat male factor infertility. For males who have just a few, barely swimming sperm in the ejaculate to males who ejaculate no sperm, the ICSI procedure can be used to directly inject the sperm into the egg. ICSI is often combined with a sperm harvesting technique such as MESA (microsurgical epididymal sperm aspiration) and PESA (percutaneous epididymal sperm aspiration), an office procedure where sperm can be obtained by passing a tiny needle through the skin into the epididymis. Testicular sperm extraction (TESE) is also an office procedure, now sometimes done with a large biopsy needle under local anesthesia, rather than being done as a full surgical biopsy, but sperm are not as reliably obtained.
The IVF cycle with ICSI is conducted exactly in the manner as a non-ICSI in vitro cycle, with a very few exceptions. After the eggs are retrieved, instead of mixing the sperm with the egg, the embryologist utilizes a thin glass pipette to immobilize the sperm, sucks it up into the pipette, and then injects it directly into the egg's cytoplasm. Since the egg is the size of a pinpoint, it is a sophisticated technique requiring a high-powered microscope, tiny glass pipettes, and instruments that translate hand movements into extremely fine movements of the pipettes.
The success rate for IVF with ICSI is about the same as for IVF, indicating that the manipulation has very little effect on the egg. However, since the female partners of these men are often reproductively normal, there may be some small adverse effect, also reflected in reports of slightly reduced embryo quality with ICSI. Most data indicates similar rates of congenital abnormalities with the general population and IVF without ICSI, although some reports suggest a minor increase of chromosomal anomalies, many of which are related to the man's genetics or his sperm, rather than the procedure itself. Because of these concerns, prenatal genetic testing with a fetal karyotype is suggested for ICSI pregnancies. Recently, there have been concerns about a higher rate of some very rare abnormalities which may be associated with IVF and ICSI, specifically Beckwith-Wiedemann syndrome which includes kidney problems, low blood sugar and an increased risk of childhood tumors.
In a proportion of men (10 to 20 percent) with very low or absent sperm in the ejaculate, the man may have a chromosome defect or a genetic defect not visible on routine chromosome analysis (Y chromosome microdeletion) that could pass on a similar problem with infertility to male offspring. Rarely, such a chromosome defect could cause a serious abnormality in the offspring. Therefore we suggest a pre-cycle karyotype for men with fewer than 5-10 million sperm per ml in the ejaculate. In men with congenital absence of the vas deferens, one can assume the male is a carrier for cystic fibrosis (CF). Since such men can have a mutation not screened for in the standard CF panel, it is recommended to test the female partner. If she is a carrier, the couple could elect to have their embryos tested for CF by testing a sample of amniotic fluid and aborting a CF fetus, or now by preimplantation genetic diagnosis (PGD) where a cell is analyzed from each embryo and only unaffected embryos are transferred.