Weights of Subsequent Babies?

I have 4 children. My first was 7 pounds 5 ounces. My second and third were nearly the same at 7 pounds 14 1/2 ounces and 7 pounds 13 1/2 ounces. My youngest was 6 pounds 14 ounces. I had Gestational Diabetes with her so it was a bit of a surprise that she was such a lightweight plus she was born at 41 weeks. I think sometimes subsequent babies weigh more, but I don't think I have ever heard it said that is the case almost all the time. I am thinking of some people close to me who I actually can remember the sizes of their babies and it seems as though there isn't really any pattern. Some had large baby #1 and small baby #2 and 3. Some had babies all within a few ounces of each other. I can't think of anyone I know who has 3 or more kids and each was born at a bigger weight than the one before.