But that, she concedes, is as likely to happen as a Vietnamese girl choosing to give birth to her illegitimate baby.

CNN: The Abortion Dilemma

Dr Wang is seeking to identify specific genetic traits that make women more likely to give birth to a low birth weight or premature baby.

BBC: Gene clue to pregnancy riddle

The authors of the study conclude that giving women the opportunity to give birth at home or in a midwifery unit saves the NHS money and is safe for baby and mother, resulting in fewer expensive interventions.

BBC: Home births more 'cost effective', says Oxford study

The zoo hopes it can breed the snails, which give birth to one baby every three months, so they can be reintroduced to the wild as part of a conservation programme.

BBC: Partula tree snail