Page URL:

Spermatid injection technique allows 'sterile' men to become fathers

9 November 2015
Appeared in BioNews 827

Men previously considered sterile have successfully fathered children thanks to a newly improved technique called round spermatid injection (ROSI).

The technique was trialled by Japanese scientists, and resulted in 14 children born to 12 couples from 2011 to 2014. The men were classed as sterile because their sperm had not developed into a classic tadpole shape, instead remaining round.

Dr Atsushi Tanaka, from the Institute for Assisted Reproductive Technology in Fukuoka, Japan, who led the trial, said: 'Although the current success rate of round spermatid injection is not very high compared with ICSI, intracytoplasmic sperm injection, this procedure can be the last resort for men who cannot produce spermatozoa but wish to use their own genetic material to produce offspring.'

These round cells are found in 30 percent of men with non-obstructive azoospermia, which affects just under one percent of the general male population. These men are deemed sterile, and couples are advised to use donor sperm to conceive.

The technique involves injecting these immature sperm directly into a woman's egg. It was first used in the 1990s, resulting in the birth of several babies, including one in the UK (Susan Louise Oxburgh, born in 1996). However, it was banned by the UK HFEA, Human Fertilisation and Embryology Authority, because of concerns about potential genetic abnormalities in these immature sperm as well as low success rates.

In the recent study, which was published in PNAS, the scientists further developed the ROSI technique by including activation with an electric current. They trial involved 76 men, using 734 eggs in total. The success rate was 16 percent overall. The children were found not to have any unusual physical, mental or epigenetic problems.

'This study is a bit like a rugby ball from leftfield. We thought that this idea was dead, that it would never be useful again. This potentially offers some of the one percent of men who don't produce sperm an interesting option,' Allan Pacey, Professor of Andrology at Sheffield University, told the Guardian.

Incorporating electrical charge to the ROSI was 'a modern twist on an old idea', he said, adding, 'This new study goes some way to making us rethink whether or not this is an avenue that we should be looking at again.'

The study authors acknowledge that further studies are needed to establish the safety and clinical value of ROSI, especially as it is less efficient than well-established methods such as IVF or ICSI. They also believe efficiency could be improved by screening sperm before use.

Birth of babies through round spermatid injection
Eurekalert (press release) |  2 November 2015
Fourteen babies born after round spermatid injection into human oocytes
PNAS |  2 November 2015
Hope for infertile men as 12 sterile men become fathers through controversial technique
Mail Online |  2 November 2015
'Modern twist' on fertility technique may offer hope for sterile men
The Guardian |  2 November 2015
'Sterile' men father 14 babies thanks to new Japanese technique
BT (Press Association) |  2 November 2015
10 October 2016 - by Rikita Patel 
The first generation of men born through intracytoplasmic sperm injection (ICSI) have lower sperm counts, according to a small study...
7 March 2016 - by Dr Dusko Ilic 
A recent announcement that scientists had created functioning spermatozoids from mouse embryonic stem cells in the lab made quite a splash in the media. However, one key point seemed to be overlooked...
25 January 2016 - by Dr Rachel Montgomery 
A new IVF technique has been developed which allows fertilisation to occur in the womb rather than in the laboratory...
16 November 2015 - by Jessica Richardson 
Researchers have discovered that human sperm have a two-dimensional 'slither' swimming mode, which enables them to swim faster when close to surfaces...
21 September 2015 - by Lubna Ahmed 
French researchers have described a technique to produce human sperm cells in the laboratory as they attempt to patent the method...
7 September 2015 - by Chris Baldacci 
Scientists have discovered that a protein in the head of sperm cells forms spiky filaments, which could act as tiny 'harpoons' that anchor the sperm to an egg...
13 July 2015 - by Rhys Baker 
A test to diagnose male infertility that uses RNA as a biomarker has been developed by researchers in the USA...
15 June 2015 - by Dr Lucy Freem 
Knocking out a single gene in adult female fish causes them to produce sperm inside their ovaries, study results show...
7 July 2014 - by Siobhan Chan 
Healthy mice have been born using sperm grown in the lab from a sample of cryopreserved testicular tissue...
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.