It is a very generous benefit that doesn't appear to be matched by other airlines. It is not well explained on the VS website, so in anticipation of an upcoming arrival, I e-mailed them for clarification recently. This is the reply I received:
Due to maternity and paternity leave, Gold members can apply for an extension to their account to retain their Gold.
We would need the following information in order to do this:
1. Put the request in writing to Customer Services team (Customer.firstname.lastname@example.org).
2. Supply one of the following documents as proof:
a) Hospital booklet (detailing birth/pregnancy)
b) Hospital letter (detailing birth/pregnancy)
c) Copy of the infant birth certificate.
What we will offer:
• Customer Services will add the amount of tier points required to maintain the members status, enabling you to continue at Gold status for a further 12 months from your renewal date.
• If you have been downgraded already, Customer Services upgrade the account back to its original status.