Here are my tips for improving the sex life after pregnancy. They helped us and we have three kids now. Maybe they'll help you too.
Time of day - for you new parents, you will soon learn that sex at night is never going to happen. Why? Because you and your wife are too tired to get into the mood. Try having your intimate times early in the day, like before lunch, and Mom will respond much better to intimate advances.
Baby sitters - The proper use of a baby sitter is not to take care of your children in your house while your leave. Ask the baby sitter to take your children to a nearby park for a couple of hours so that you can be alone at home with your spouse for some intimate time. If you have older children and a baby, have the baby sitter take the older children out and schedule the sitter for baby's nap time.
Ladies, turn off your brains! Usually when you finally get your husband alone you want to tell him everything you are thinking and feeling and about the baby etc. This is a good thing to do when you are tired but a bad idea when you finally have a chance for sex.
But you say, if I don't tell him everything I will just think about it and not be into sex. Point noted. Here is the solution:
Men LEARN MASSAGE!!! Start on feet, hands, back etc. Give your wifes 30+ minutes of massage before starting getting the intimate parts. This will give your wives a chance to start thinking about how nice it is to be touched by a man and not an infant.
Ladies you have to help. While getting this much deserved pampering, no talking about kids, friends, sisters kids, phone calls with mothers etc. You need to concentrate on enjoying intimate time. Your husband deserves your help here. Eventually you body will start to respond to the massage and very nice and intimate sex can happen while you are still breastfeeding.
Finally ladies - do not lay on your stomach and on your breasts - you will get milk clogs and sore breasts. We use two mattresses on the floor and leave a 6 inch crack between them. My wife lays so that her breasts hang and there is no pressure on them.