Clear your diary for the rest of the week to accommodate twice daily trips to the Fracture Clinic.
Start collecting pound coins several weeks in advance to feed the ticket machines in the hospital car park. My experience suggests £20 in loose change is required in a 36 hour period.
Fill yourself up guiltlessly on the party food because it might be several nights before you eat a proper meal again.
Dispense with your contact lenses to create immunity to the posters papering the hospital waiting area warning that your tiredness/aching limbs/confused brain/nightly lager are forerunners of an early death.
Rehearse a repertoire of lavatorial jokes to distract your small companion during the four hour stints in said waiting area.
Carry at all times a small pot of jelly beans with which to disarm flustered nurses.
Make up the spare room bed before the big day so that you do not disturb your slumbering spouse when you and the birthday boy stumble in from A&E at 1am.
Forewarn your workplace that you will require flexible deadlines for at least three days following the event.
See? Easy once you know how! And now, forearmed, you can relax and enjoy the unique bliss of mothering...