There is a book in the U.S. (your dh might be able to get it for you -- or order it while abroad) it is called "When you are expecting twins, triplets or quads" by Dr. Barbara Luke and Tamara Eberlein. It is HUGE in the U.S. and alot of twin moms report some great results from the book. The focus of the book is on nutrition and it recommends gaining 24 lbs. by 24 weeks or one lbs per week. After the 24 weeks the book recommends 2 lbs per week. (2.2 pounds = one kilogram) I've read alot of twin websites message boards and women are reporting nice big babies (like 5 lbs and 6 lbs size) being born.