My wife and I are expecting our second child this fall. Our first is in kindergarten and so we are locked into only traveling on school breaks when flights cost lots of points (or dollars).

I see the itinerary for exactly what we want now for next spring break, flying IAD-HNL (UA metal) and HNL-LIH (HA metal); this flight is already, 9.5 months out, only available to me due to having a UA credit card. If I redeem points to book the three of us who have been born now, I assume I can add the lap baby to the reservation after she is born and has a DOB for the PNR.

My questions are:
(1) Will this trigger a re-price (in points, at least) of the ticket we attach the infant in lap to?
(2) Should I brace for any issue with the lap baby being added to the PNR by UA not getting through to HA's computers when we switch flights in HNL?

Mahalo!