Sperm vacuoles are linked to capacitation and acrosomal status

Is the presence of nuclear vacuoles really a negative parameter?

As sperm vacuoles are associated with acrosomal and capacitation status, they appear to be a reflection of normal sperm physiology.

The selection of sperm under a high magnification has been proposed as a strategy to increase the success rates of ICSI, through a better selection of sperm for injection. The presence of vacuoles on the sperm head is said to be a negative parameter.

We incubated processed sperm for 90 min with two strong inducers of acrosome reaction (AR), i.e. hyaluronic acid (HA) and follicular fluid (FF) and studied the evolution of nuclear vacuoles, sperm morphology and chromatin compaction.

We tested the effect of incubating sperm samples with HA and FF for 90 min at 37°C on nuclear vacuoles.

Both HA and FF strongly induce AR after 90 min, without significantly modifying sperm nuclear condensation and morphology (Bartoov's criteria). We simultaneously observed a highly significant decrease in the presence of vacuoles.

This is a descriptive study based on in vitro manipulations.

Although intracytoplasmic morphologically selected sperm injection may be of benefit for couples with specific treatment indications, the results of this study make it difficult to justify its large-scale application.

Funding was granted by Laboratoire d'Eylau, Unilabs.