Girl twins lose out in womb

Published on Tuesday 2 June 2009 20:13

A GIRL with a twin brother may be disadvantaged from birth after losing out in the womb, new research suggests.

A study of wild sheep found that a female lamb with a male twin sibling was 10 per cent lighter at birth than those with twin sisters.

Females with male twins were also less likely to survive their first winter and had fewer offspring over their lifetime.

The findings show male embryos out-compete females for nutrients when they are together in the womb, scientists believe. The research was carried out on a population of wild Soay sheep on the island of Hirta, St Kilda, by a team led by Dr Peter Korsten, from the University of Edinburgh.