I also think that the bond extended breastfeeding builds with your little one is invaluable. I'm a great believer in the security that you give a child leads to them being confident and independent as they grow and breastfeeding (even a toddler/child and even once a day/night) is so much more than just nutrition, although these benefits are great. There aren't many studies out there for breastfeeding older children but there are so many women who do carry on for many years, we just don't see it in public much. For those who want to read anything more there's a book called Breastfeeding Older Children by Ann Sinnott. Personally, I would always stop when you are both ready (and you'll know when that is), then there are no regrets either side. You'll still have milk even if you don't always feed every single night.
Bookmarks