Scientists build 'synthetic embryos'

Dutch scientists have built "synthetic" embryos in their laboratory using mouse cells other than sperm and eggs.

The stem cell breakthrough, described in Nature journal, is not for cloning people or animals, but about understanding why many pregnancies fail at an early stage - implantation.

The embryos, made in a dish, attached to the womb lining of live female mice and grew for a few days.

Studying the process could help human fertility, BBC News reports, citing experts.

Many miscarriages occur before a woman is even aware she is pregnant, when the fertilised egg does not manage to implant in the womb.

Experts do not fully understand why this occurs, although it is likely to be linked to abnormalities in the growing embryo.

Studying how early embryos develop is tricky both ethically and technically.

Using stem cells, rather than sperm and eggs, to make model embryos could offer a plentiful supply for scientific research.