Most abnormalities in ICSI babies linked to multiple or premature births
Fears that the controversial fertility treatment known as ICSI could cause a high level of abnormalities among babies are largely unfounded, according to major new research by Swedish fertility experts, published today (Wednesday 29 March) in the journal Human Reproduction.*
A study of over a thousand babies born after ICSI did show that there was an increased risk of abnormalities compared with babies born without the use of any fertility treatments, but that this was mainly due to conditions generally associated with multiple or premature births rather than the ICSI technique itself. More than a third of the ICSI babies in the study were multiple births. However, the researchers did identify one condition that appeared to be directly associated with ICSI -- hypospadias -- a malformation of the penis.**
ICSI involves injecting a single sperm directly into a woman's egg and has been used since 1991 for men with severe fertility problems. There have been concerns that the technique could lead to abnormalities because of its nature and the quality of the sperm. Studies to date have shown conflicting results.
Using data from the Swedish Medical Birth Registry and the Registry of Congenital Malformations, the researchers compared the rate of abnormalities recorded among ICSI babies with the rate among all Swedish births and babies born by conventional IVF. Among the ICSI babies the risk of abnormalities was 75% higher than among the general population with 87 cases of some sort of malformation. Nearly half the cases involved only minor conditions.
Dr Ulla-Britt Wennerholm, senior registrar at Göteborg's Sahlgrenska University Hospital, said: "Although we found an excess risk among ICSI babies compared with babies born without fertility treatment, most of this was due to conditions associated with multiple and premature births rather than ICSI. The one condition that seemed to be over-represented among ICSI babies was hypospadias, where we identified seven cases compared with an expectation among the general population of around two. We know that hypospadias appears to be particularly associated with paternal fertility problems so a link directly with ICSI is plausible."
But she said that overall the results should encourage couples whose only hope of having a family was through ICSI. "About 20,000 babies have been born worldwide through ICSI in the last decade and the vast majority of these are normal, healthy children."
The research is continuing with further analysis of the malformation rate in all the ICSI children born in Sweden -- 2,000 so far. "Larger studies are essential to study specific malformations that occur at a low frequency," said Dr Wennerholm.
There is also an ongoing prospective study on the ICSI children involving a paediatric and psychological examination when they reach the age of five.
* Incidence of congenital malformations in children born after ICSI. Human Reproduction. U-B. Wennerholm et al. Vol 15. No 4. pp 944-948.
* * Hypospadias: a congenital abnormality of the penis in which urine is passed through an abnormally placed opening on the undersurface of the body of the penis. The condition is normally treated by plastic reconstructive surgery in childhood.
Notes:
1. Full embargoed text of the paper with participating research teams can be found from 29 March on website:
http://www3.oup.co.uk/eshre/press-release/april.pdf
2. Human Reproduction is a monthly journal of the European Society of Human Reproduction and Embryology. Please acknowledge Human Reproduction as a source.
3. The study was supported by grants from the Göteborg Medical Society and the Regional Authority of West Sweden.
4. Printed text available on request from Dr Helen Beard, deputy editor:
Tel: +44 (0) 1954 212404 or email: gb54@dial.pipex.com
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Journal
Human Reproduction