There are issues, and it's only natural to think what you are thinking, but it does all fall into place - trust me! LOL. Yes there are times when you do feel overstretched and can't be there for them all at once, but you work around it. I had my first three pretty close (20mths) and it was wonderful and I don't feel that I missed out on any part of their development. It's the most amazing thing to see them interract with their siblings at a young age and there are so many special moments. Also milestone aren't any less significant when a new baby does them - because it's THEIR milestone they have reached kwim? Those first smiles, and giggles and all the little things are still as precious as they were the first time. And your heart just grows bigger each time. Dont forget too that by the time a new baby is born, the older one/s are doing things for themselves and dont' need as much of your time kwim? By then you are usually in your 'groove' too so it's easy to adjust the family routine to fit another one into it.