although st mary 's hospital in london is the first choice of venue for the delivery , two other hospitals have been put on standby in case the duchess leaves the capital .
but it is understood that the royal berkshire in reading and queen elizabeth hospital in king 's lynn , norfolk , have been told to prepare in case she goes into labour nearby .
the duchess 's private obstetricians have been warned that they could be called to either location , the daily telegraph reports .