My bitch has always been quite an easy going, well behaved little thing. She was usually walked without a lead as she was very good at  "come here" and "stay". Then about a year ago she had her first litter. Everything went well and she was a good mother . But somehow the whole experience seemes to have changed her a bit - as she now quite often behaves in a very superiour way. The old rules for behaviour when out walking doesn't count anymore she has decided. Either she doesn't hear me at all ( I have checked that her hearing is all right),or she stops and looks at me as if she is surprised  -  Surely I must be speaking to some other dog somewhere ......  So lately we have been going back to basics and things are at least improving.

     I am now wondering if this is quite common in bitches after they have had puppies. Do they somehow feel that their place in the world have changed - that they have moved up in the hierarchy - and thus is a more superiour creature ?

Most definately!  I suppose it may have something to do with the fact that wild canids that breed are the alpha individuals in the canine social system, so breeding would elevate their status.  also it could be that quite rightly we spoil them rotten while they are working so hard, and let them have treats and priveledges not normally allowed.  they also have to have authority over their young.  so it is probably a mixture of things.

I do find that having puppies makes for a closer bond with me and the bitch, as she is totally reliant on me to provide for her an them, and it is a huge amount of trust that you have given.

Yes it fits in with the wild canids,doesn't it - only the best geens are carried forward, so only the alpha bitch (or bitches ?) has the privilige of having babies.
But I still hadn't expected to find it expressed in such an obvious way in my bitch - strutting around like royalty.  - I hadn't though of your other points though .. Yes of course she was spoiled rotten, with all kinds of priviliges and plenty of lovely food. Which I suppose must have given her the message that she was indeed someone important.
The authority thing over her young I am sure also plays a part as we have kept one of her offspring. I suppose that's why her superiour attitude is still so obvious after almost a year. Her attitude towards her silly little rascal of a daughter is however very generous and tolerant, and she will still accept her in her food bowl.

Oh yes! Mine is much more confident now, which has benefits in the show ring, but not so in the fact that she thinks every dog is her responsibility to keep in line!

well Daisy has definitely become more arrogant since she had the pups.All the rules, ie having her feet wiped when she comes in etc are beneath her now, because she is the queen of the household.She is even refusing to go out for wees when it's raining now!!!It's quite funny really, but she has been getting special treatment and tons of praise off everyone, so she's probably lapping it up and making the most of it!!