New Microscopic Technology Aids In Reproductive Assistance

A new technology allowed scientists to perform clinical sperm analysis without staining the samples.

According to the Centers for Disease Control and Prevention (CDC), around 10% of women in America ages 15-44 have trouble with conceiving or having a full-term pregnancy. ART or Assisted Reproductive Technology, is a procedure in which eggs are fertilized with sperm in vitro and then put back in a woman's uterus, which is often the last option for couples who have a hard time conceiving a child. However, the physical, emotional and financial stress that this procedure brings is high, as the success rate of using ART is just around 20-30%.

In a study recently published in the journal Fertility and Sterility, new technology from the Tel Aviv University has allowed scientists to perform clinical sperm analysis without staining the samples, which usually greatly affects the viability of the sperm.

Sperm cells are usually transparent under usual microscopic methods. Their optical properties are quite similar to their environment, which causes them to have a weak image contrast. If the sperm cells are to be used in fertilization, they cannot be stained, as staining might possibly damage the resulting fetuses.

The important point is to be able to pinpoint strong sperm candidates without the use of staining, while at the same time still being able to determine their viability.

Sperm Cells and ART

The research was led by Dr. Natan Shaked, PhD, who is from the Department of Biomedical Engineering at TAU's Faculty of Engineering, along with his master's student, Miki Hifler, MD. Sperm cells that were used for the study were acquired from the Male Fertility Clinic at Chaim Sheba Medical Center which is located in Israel.

At present, there are two available ART methods. One is in vitro fertilization or IVF, in which a woman is given medicine that makes her produce more eggs in her ovaries. These eggs are then placed in a petri dish with a man's sperm cells for the purpose of fertilization, which is done in a period of three to five days. The other method is called intracytoplasmic sperm injection (ICSI), in which a single sperm is injected into a mature egg cell, which is then transplanted into a woman's uterus. The method discovered by Dr. Shaked can be used in both methods, but is more useful in ICSI.

The device, which is a small black box attached to a microscope, is small, cost-effective, and even easier to use as compared to usual existing interferometric imaging methods. This is then connected to a new kind of software that allows a thickness map of the sample to be viewed, along with other physical parameters that measure the sperm cell's viability at present. The device only costs $1,000, and is very flexible because it can be used in any physician's clinic that already has a conventional microscope.

Dr. Shaked believes that his invention, which uses phase imaging methods to record the passage of light through a sample to determine how thick it is, can accurately tell the quality of sperm cells used in ART, which may surely lead to higher success rates in the procedures.