Because infant death and stillbirth are relatively rare, the increased risk does not equate to large numbers of deaths. In England and Wales, nearly five babies were stillborn for every 1,000 live births in 2013, according to the Office for National Statistics, and infant mortality in the UK was 3.8 per 1,000 live births in 2014. Among women who have put on significant weight – a rise in their body mass index (BMI) of 4 points or about 11kg in an average-height Swedish woman – there would be about two more stillbirths and the same number of extra deaths per 1,000 births.