One in five babies born in Britain last year was born to a woman from overseas, according to the first official analysis of the impact of migration on fertility. Immigrant mothers are having far more children than their British counterparts - fuelling the biggest rise in population since the 1960s baby boom. The highest birth rates were among Pakistani, Indian or Bangladeshi-born mothers, who gave birth to five per cent of all UK babies last year. A further four per cent were born to mothers from EU countries outside Britain and Ireland, with a growing number from eastern Europe. The...