I wasn't poly when my toddler was born but I'm hoping to still be part of a trio when the next baby comes. I can tell you, this relationship was given a big assist by my pregnancy hormones. So I hope it lasts past the birth of my daughter.
My hopes for our relationship when the baby comes:
1) Knowing that my husband has another lover will allow me to listen more closely to my body and libido. I won't feel the need to have sex so that he feels attractive and appreciated.
2) Extra hands to help with the myriad things that a newborn, toddler, and postpartum mama need. Especially because my husband will be working full-time rather than having the super flexible schedule of a graduate student this time around.
3) An opportunity to see myself as an adult woman and not just D&B's mommy 100% of the time (we practice attachment parenting, so it can get pretty all-consuming).
I do worry that my husband and I may pull back from K due to sheer exhaustion. I hope that all goes well and that she gets what she needs from the relationship.