A woman in Bristol has given birth to quadruplets, who were all born on \"leap day\", 11 weeks early. Emma Robbins gave birth to four boys by Caesarean section within six minutes of each other on Wednesday night at St Michael\'s maternity hospital. Zachary, Rueben, Joshua and Samuel are all said to be doing well. The smallest baby weighed 2lb 8oz (1.1kg), the heaviest weighed 3lb 1oz (1.4kg). All four were conceived naturally, and two of the babies are identical twins. \'Exceedingly rare\' A consultant said it was \"exceedingly rare\" for quadruplets to be conceived naturally. The babies were born after 29 weeks and one day of pregnancy, on 29 February. Speaking before the birth, Mrs Robbins said she was surprised when she found out she was pregnant with four babies. She said the ultrasound operator broke the news to her and her husband, Martin. Mrs Robbins explained: \"She said \'have you got twins in the family?\' \"She then went really quiet and turned the screen to us and said \'actually, I can see three sacs\'. \"Then she started counting and said \'there\'s two in the third sac. It\'s quads\'. \"We were really surprised.\"