As confinement is the period from the onset of labour to the birth of a child, then thoughout confinement, the Mum-to-be is in labour. The the "lead-up to" is indeed poor wording - it would be better as "usually in confinement" or "usually in lead-up to birth".
Peter = Safe was a new one on me BTW
And - why is 4D Libido - from In basic Instinct hero almost welcomes offer. I get anagram of Idol and BI - but what's the rest of the word play, please?