What is HBA-IMSI – two-stage sperm selection

HBA-IMSI is a combination of IMSI and HBA, i.e. the morphological selection of the sperm under very high magnification (IMSI) with the receptor reaction of its head with hyaluronan (PICSI/HBA).


The selection of spermatozoa with the optimal morphological structure is performed using the highest quality Nomarski contrast optics, supported by special software and the expertise of a highly qualified clinical embryologist. IMSI can identify very subtle abnormalities in the structure of the sperm head, which are invisible during standard IVF.


Sperm selected by the IMSI technique are re-selected based on their ability to bind to hyaluronan via head surface receptors. The sperm selected in this way is very likely to be biologically mature and functional. This can increase the chance of the egg fertilising, producing a normal embryo and developing pregnancy, and reduce the risk of miscarriage.

Two-stage sperm selection offers the chance to obtain better embryological results and achieve pregnancy in patients with failures in previous treatment attempts.

Examples of indications for the use of HBA-IMSI two-stage sperm selection:

  • history of miscarriage, including that associated with male factor,
  • severe teratozoospermia (sperm morphology 0–1%),
  • abnormal sperm chromatin together with abnormal sperm morphology,
  • previous unsuccessful attempts to achieve pregnancy with ICSI and IMSI (few developing embryos, low quality embryos, no blastocysts, no implantation).