Should I Pay Extra on the Mortgage Principal?

I’ve been paying extra on the mortgage for a year and a half now — I always pay at least $25 extra a month toward our mortgage principal, with a few months of an extra $50, up until our escrow payment increased $100/month this past August, after which I just rounded up to a nice, even number and paid an extra $23.

Fast-forward to last week, when we received an escrow disclosure statement/notice of new mortgage payment in the mail from our mortgage company. The good news is it indicates that starting in February, our total mortgage payment (which includes an escrow payment for property taxes and homeowners insurance) will decrease by $46 per month.

But with Baby Frugalista scheduled to arrive in early March, I’m wondering if that money would be better spent on, well, things for the baby. She’ll require diapers, wipes, and possibly formula if nursing doesn’t work out the way I hope. These items will alter our budget. Then there’s the savings account(s?) I want to open for her.

Another consideration is that I plan to stay home for 6 months after the baby is born, which means I’ll only be receiving 66% of my pay for 12 weeks or so, then nothing for the next 3 months. So our finances will be squeezed as it is — why make it worse by “spending” $25-$50 on an additional mortgage principal payment?