MACS

Male infertility is a major cause of infertility in over 40% of couples, and in many cases the issue is not just the number or mobility of sperm cells, but also their genetic quality. A significant percentage of men present sperm DNA damage, a phenomenon associated with reduced fertilization rates, poor embryo quality and recurrent pregnancy loss. In such cases, a modern laboratory technique known as Magnetic-Activated Cell Sorting (MACS) can make the difference.

What is MACS – Magnetic-Activated Cell Sorting?

MACS is an advanced sperm preparation method used in the in vitro fertilization (IVF) lab. Its goal is to eliminate sperm cells that show signs of apoptosis (programmed cell death) and DNA fragmentation. These sperm cells are marked with magnetic microbeads that bind to specific cellular markers, such as phosphatidylserine, associated with membrane damage. After the cells are labeled, the sperm sample is passed through a magnetic column. The damaged cells remain attached inside the column, while the healthy sperm with intact DNA pass through and are collected for procedures such as ICSI or IVF.

Who can benefit from MACS?

MACS is not recommended for all patients but is indicated in specific clinical situations where the risk of sperm genetic damage is increased.

1. Men with high sperm DNA fragmentation (DFI > 30%)

This is the group that benefits the most from MACS. Studies report higher pregnancy and live birth rates in couples who used MACS-selected sperm, in both autologous cycles and those with donated oocytes.

2. Couples with unexplained infertility

In these situations, MACS can improve functional sperm parameters and increase fertilization rates in subsequent assisted reproduction cycles.

3. Male infertility cases with abnormal sperm morphology (teratozoospermia)

Using MACS may lead to higher-quality embryos, particularly when the female partner is over 30 years old.

4. Men with varicocele

Varicocele is commonly associated with increased sperm DNA fragmentation. By eliminating damaged cells, MACS can significantly reduce fragmentation and improve the reproductive potential of sperm.

5. Couples with repeated IVF/ICSI failures

In these cases, additional sperm selection with MACS can improve sperm quality, with results comparable to those obtained from sperm retrieved from epididymal aspiration or testicular biopsy (TESE).

What does the research say?

Clinical analyses and meta-analyses published in recent years show that MACS can increase pregnancy rates and reduce miscarriage risks in patients with damaged sperm. However, evidence regarding improved live birth rates remains limited, requiring further research.

Even so, for couples dealing with male-factor infertility, MACS offers a real chance to enhance treatment outcomes, though it does not guarantee success. It is an additional technique that can bring benefits in selected cases.

Why choose a laboratory that offers MACS?

In a modern IVF lab, MACS technology is integrated into personalized protocols for patients with high sperm DNA fragmentation or repeated implantation failures. The goal is simple: to select the best sperm cells to increase the chances of obtaining viable embryos and a successful pregnancy.