We bought vials for future use in January of this year and DS was born in April. We knew we wanted our son to have a bio sibling if possible. The thing that scared us a little was that sometimes our donor was available and sometimes he wasn't. (We used Xytex and you can see if a donor is available at any particular time, but you have to call to see how many samples they actually have.) So, when we saw he was available again, we decided to buy and store the samples to hopefully use for next year.
Thigns I would consider since you're using a bank are:
-Is the donor active? We knew that even though ours wasn't available at certain times, he still was presently coming in to donate. So the likelihood of him being avilable even next year was pretty good with the whole quarantine thing. If he wasn't active and those were the only samples left, that would be good to know so that you don't run the risk of running out of time to purchase.
-Are you willing to pay the storage fees or just take the risk that your favorite donor might not be available the next time? I know some places do have something where even if the donor 'retires' some samples are set aside for those that have previously had children with them.
Ok, so that's only two things and they're basically the same.
In the end we did it before our son was born so we could be assured we'd get the donor we wanted. Also, we thought, "We better buy up before Ray comes in case we change our mind."
But in all honesty, financial situations can change quickly, and it's possible if we hadn't purchased them when we did we might not have been able to buy them later on when we needed them.
The only other thing to consider, which would maybe support waiting until after the birth, is the overall health of your current baby, unless that doesn't matter as much to you. It's something no one likes to think about, but if your baby ends up having a birth defect and it's possible it was linked to the donor's side, would you still want to try again with the same donor? For us, we never really considered there'd be any problems, and the pregnancy went well, so we just bought them before DS arrived.
Good luck with your decision. I know we struggled a little bit trying to figure it out. But I feel comfortable knowing we do at least have enough for a few tries waiting for us when we're ready again.