Some men often believe the mark of their virility is their machismo in bed and the volume of ejaculate they can release at each orgasmal round of sexual ecstasy. But none of these unfortunately translates to fertility.
A normospermic sperm sample usually has a minimum count of twenty million forwardly progressive motile spermatozoa per milliliter of semen. An average of five millilitres of semen is often released per ejaculate quantified.
With normospermic counts, all twenty million spermatozoa take to a dash after ejaculation - towards the egg released from the woman’s ovary. Under normal circumstances, a normospermic count should sufficiently get a woman pregnant with timed intercourse, but that is not always the case when there is an underlying misnomer in the sperm’s genetic property.
After comprehensive fertility assessments have been done on the couple and neither male nor female factor infertility is indicated, some IVF centres may proceed to label the situation as unexplained infertility.
However, a conclusive infertility diagnosis may just be achieved by subjecting the husband’s spermatozoa to Sperm Chromatin Structure Assay (SCSA) - which assesses the underlying genetic viability of the sperm, and its ability to sustain the initial stages of embryogenesis - if fertilization peradventure occurs prior to an embryonic arrest.
Most sperm cells with damaged or fragmented DNA usually do not proceed to fertilise an egg, and if they manage to get past fertilization events, the embryo usually arrests and is unable to proceed with further cellular divisions. Certain conditions and practices predispose men to having sperm cells with fragmented DNA; these include excessive smoking, frequent hot tubing, exposure to high levels of air pollutants and other toxic substances, extended duration of sexual abstinence and age (significant from about ages fifty and above), among others.
The test is performed using an instrument called a flow cytometer where sperm cells which have been stained with fluorescent dyes are made to pass through glass channels. The cells flow in a liquid suspension and are analysed by a laser beam which measures the DNA Fragmentation Index (DFI) of the sperm cells by the light emitted from the fluoresced cells. Green fluorescing sperm cells have low levels of DNA fragmentation while red fluorescing sperm cells show moderate to high levels of DNA fragmentation. DFI values above thirty per cent in a sample of semen analysed show significant lack of fertility potential as a result of sperm cells with immature chromatin arising from less chromatin condensation in the sperm nucleus.
Fifteen to thirty per cent DFI values show a moderate or borderline fertility potential; and less than fifteen per cent DFI values show a strong fertility potential.
Some research studies have shown that even with normospermic parameters that consider sufficient motility, morphology and quantity, such samples with thirty per cent DFI values and higher only resulted in positive pregnancy in less than one per cent of the studied cases. Androcare labs also conducted free SCSA test for 10 normospermic men (with the right sperm parameters) but who battled with unexplained infertility.
The results showed that seven of them in fact had a DFI value above 30 per cent which means that their seemingly normal sperm cells in sufficient quantities had deficiencies in their chromatin structure as result of DNA fragmentation - and hence their inability to get their wives pregnant.
There is currently no diagnostic andrology centre in Nigeria furnished with the ability to run the Sperm Chromatin Structure Assay - except for Androcare Laboratories and Cryobank - who are in a strategic partnership with a US-based diagnostic company. For cases of unexplained infertility in situations where male or female factor infertility has been ruled out, the next line of action may just be to consider conducting the SCSA test to further improve the chances of achieving pregnancy.