A preliminary study has revealed that human sperm samples exposed to micro-gravity conditions retain similar characteristics to those kept on Earth.

The study was conducted using a small aerobatic training aircraft (CAP10) that can provide short-duration hypogravity exposure. The results were reported at the 35th Annual Meeting of the European Society of Human Reproduction and Embryology (ESHRE) investigators.

It suggests that frozen sperm could one day make its way to space and open the possibility of creating a human sperm bank outside Earth.

The study results are presented in Vienna by Dr Montserrat Boada from Dexeus Women’s Health in Barcelona.

Boada’s team worked with Polytechnic University of Barcelona’s microgravity engineers, while the parabolic flights were created by the Aeroclub Barcelona-Sabadell of Spain.

Boada said in a statement: “Some studies suggest a significant decrease in the motility of human fresh sperm samples, but nothing has been reported on the possible effects of gravitational differences on frozen human gametes, in which state they would be transported from Earth to space.”

As part of the study, CAP10 executed a series of 20 parabolic manoeuvres, providing eight seconds of microgravity to ten sperm samples.

The samples were analysed after exposure to the different microgravities found in space and ground gravity.

A complete range of measurements such as concentration, motility, vitality, morphology and DNA fragmentation, which are currently performed for fertility testing, were included in the sperm analysis.

No difference was found in any of the parameters between the microgravity space samples and the control group samples from Earth.

Boada said: “There was 100% concordance in DNA fragmentation rate and vitality, and 90% concordance in sperm concentration and motility.”

According to Boada, the team will now focus on validating the results and then move on to larger sperm samples, longer periods of microgravity and even fresh sperm.

She added: “If the number of space missions increases in the coming years, and are of longer duration, it is important to study the effects of long-term human exposure to space in order to face them. It’s not unreasonable to start thinking about the possibility of reproduction beyond the Earth.”