A new technology has been developed that could assist in selecting high quality sperm for use in in vitro fertilisation (IVF). The work, published in the journal Nature: Microsystems & Nanoengineering, highlights the need for improved techniques to tackle male infertility.
An overlooked subject
Although around 1 in 6 individuals are affected by infertility, the topic is often overlooked. The emotional impacts of infertility are often more intense than the physical effects, and discussion around the subject can feel somewhat taboo. IVF revolutionised the field of reproduction back in the 1970s, yet nearly 50 years later, IVF still has a 78% failure rate.
Whilst vast amounts of research have gone into ensuring the highest quality eggs are used in the process, the same cannot be said for the selection of sperm. Sperm defects are responsible for around a third of infertility cases, yet the traditional methods for selecting which cells to use in IVF often lead to cell death. To combat this problem, and potentially improve the success rates of assisted reproduction, the researchers from Sydney developed a 3D-printed device to choose high quality sperm.
The new tool mimics the structure of the female reproductive tract, effectively simulating the natural journey of the sperm. This allowed the researchers to analyse the migration pattern and motility of the cells, an indicator of quality, in a more natural environment than is currently used. The team also assessed the ability of the cells to traverse the boundaries of this simulated reproductive system.
They followed this assessment by looking at the expression of apoptotic protein markers displayed by the cells. These features can be used to predict the likelihood of cell death. Identifying sperm displaying these undesirable protein markers allows them to be removed from the pool. This part of the process was deemed optional, as the motility-based exercise alone garnered good results.
Overall, by assessing sperm within this 3D-printed environment for both motility issues and apoptotic protein markers, the cells selected for use in IVF displayed an 85% increase in DNA quality and 90% less chance of cell death than those selected using traditional methods. The technique was quick and easy to use, selecting high quality sperm in as little as 15 minutes. This is a vast improvement on current sperm selection methods, and the decreased amount of time spent outside of the body further contributed to the integrity of the sperm.
Figure 1: Image describing the new technology. Sperm migration and motility is assessed during stage 2, whilst the expression of apoptotic markers is (optionally) assessed during stage 3. Adapted from Vasilescu et al., 2023.
Hope for the future
With somewhere between 1-2% of children conceived via IVF annually, it is surprising how little sperm selection techniques have evolved. The current study highlights a robust mechanism that provides a novel avenue towards solving issues that arise due to sperm quality. Should the method be widely adopted, it has the potential to significantly improve the lives of the millions of individuals struggling to conceive. However, there are further clinical steps needed to assess the true value of the system. Discussing the development of the technology, author Majid Warkiani said: “We conducted extensive testing against conventional IVF selection methods, with the new method showing an 85% improvement in DNA integrity and an average 90% reduction in sperm cell death. The sperm selected by our method also demonstrated better recovery after freezing than traditional methods.”