The author (Swedish) did the groundbreaking photos that first showed life in the womb, and was showcased long ago in Life magazine. I believe this book is related to an amazing PBS special of the same name. Amazing photographs.
If you are looking for a book with color photographs of birth, this is an excellent choice. It is a bit graphic in parts of the book, so you may not want to let your children flip through this book without your close supervision, but other than that, it is an AMAZING book, showing human life at it's most earliest stages.
My 8 year old daughter really enjoys looking at the pictures of the baby in utero. Be warned that there are some anatomical shots in the beginning on how the baby is conceived and some graphic baby-being-born shots at the end. Since she was already wondering about sex,her curiosity and things said by her classmates, we've used it. Most of the book focuses on the baby's development.