Low sperm counts passed on through IVF

 作者:申屠邂     |      日期:2019-03-08 06:17:00
By Nicole Johnston in Washington DC SONS conceived by an IVF technique in which sperm is injected into the egg are likely to inherit their fathers’ fertility problems, a genetic study has confirmed. The technique, intracytoplasmic sperm injection (ICSI), has enabled many men with very low sperm counts, or whose sperm do not swim normally, to become fathers. But doctors have warned that ICSI may allow the kind of genetic defects that cause infertility to be passed on rather than being weeded out of the human gene pool. Sherman Silber, director of the Infertility Center of St Louis in Missouri, and colleagues at the Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, studied four boys conceived by ICSI. All four inherited a deletion on the Y chromosome within a region called AFZc, already linked to male infertility (Human Reproduction, vol 14, p 1722). Other researchers are reporting similar findings, says Silber. But infertile couples turning up at his clinic seem unconcerned. “Patients are warned of this risk but still want their own genetic child anyway,” says Silber. “They seem relieved that their child will be no worse off than them because the deletion is no worse.” Joe Conaghan, director of the IVF laboratory at the University of California, San Francisco, says that 13 per cent of men with very low sperm counts are infertile because of deletions on their Y chromosome,