We banked the cord blood and the a part of the cord. It costs money and may never be used but if we ever did need it we will have it. While it costs money up front, I think it is a wise investment and over the life of your child will most likely end up not being a ridiculous amount of money. Think of it as insurance.
To be fair, I don't think its necessarily sci-fi now. I believe it HAS helped families already. But it is clearly at the early stages and there are very very very few situations where it would help the OP. But that's like most insurance. Most people's houses don't burn down in fires, either. Nonetheless, I'd still argue the issue the OP should be looking at more then cost/benefit is waiting to cut the umbilical cord. Google can get you all kind of research on that. Google "wait to cut umbilical cord" and associated. In short, the umbilical cord provides nutrients and oxygen to the baby, and it is automatically self-regulating, so the baby will "pull" more towards him/her, or not, but it takes some time. Those stem cells you want to "bank", those are the ones your baby needs immediately after birth, and it can be quite useful to the baby, especially if premature or it has some post-birth issue. They are stem cells, right. Anyways, google will get you more. The problem is that in a traditional hospital setting, even with a clearly discussed and predefined "birth plan" that notes you want to wait to cut the umbilical cord, doctors are so robotic and so worried about following their processes and procedures, AND your wife is giving birth, and you're a nervous wreck and it comes down to you (future dad) to make sure they follow everything you and your wife want, and often it doesn't happen. There are other little things like this, too. The bath for example. There is nothing that says your newborn has to be bathed so soon. In fact, some would argue the baby keeping its "coating" of "stuff" is helpful for babies skin, etc. But at the hospital they bath almost immediately. And certainly you are well well well within your right to demand the baby stay in your room at all times, as opposed to spending time in the nursery. They may require some trips to the nursery for weight checks, etc. but you should definitely accompany the baby. So I'd suggest OP does not store the cord blood and does try and hold off on clamping. All that said, all of the above doesn't matter a ton in the grand scheme of things. It just goes to show you how many new decisions you will have to make on a daily basis that seem to really really matter now, as opposed to the trivial decisions you made before becoming a parent... good luck!
From time of fertilization to birth the average is 38 weeks. If you backtrack to the time of the woman's last period, it increases to 39-40 weeks - bro.
But in most cases the doctors and inevitably the patient tend to go by the time of the last period instead.