Just wanted to add a few thoughts, fwiw. We only have one child DS, 6 with CF. I always wanted a big family but alas God had other plans. The first 6 weeks are brutal and sleepless, with waking every 2 hours or so, plus treatments. You won't have the childbirth recovery and I'm assuming you aren't nursing (I know it is possible to trigger with hormones etc.), and with formula they do sleep longer. But it will still be a rough 6 weeks and about 12 before more normal sleep patterns. My closet friend has 3 little ones by adoption, close in age and as she said you just resign yourself to no sleep for 6 weeks. But on the other hand, she notes how the kids now entertain themselves and play in ways that I sooooo envy! So later it might be easier. And of course, there's nothing like the gift of a sibling and something that pains me greatly that our son doesn't have; although obviously the gift of a healthy mom is the other part of the equations. One other thing I'll through out: Not sure if there are chances of higher-risk in the pregnancy or health challenges for the baby given the couple's situation ...if so that is another factor as far as sleep, time demands, etc. Good luck with your decision and know of prayers.