Atkins is good. Restricting your carbs is good. The reason is, (you see most people knock atkins before ever actually reading about it, or doing it the correct way) when you are overweight, and you eat carbs, your body (ie metabolism) breaks down the carbs that you are eating. When you do not eat carbs, or eat very little, your body turns your fat into energy and burns it instead. That is why the weight loss.
If atkins is followed properly it is very good and healthy. You don't have to be on atkins for the rest of your life, but you also cannot just start eating a bunch of junk and expect to stay small. If you continue to eat healthy and properly according to the last phase of atkins then you will not gain the weight back, but most people don't do this and then complain when they get heavy again.
Atkins is very healthy. Lots of people say that it isn't, but they are the ones who have not read about it and figured out why it is healthy. Before I read information on it I said the same thing. But scientifically it is very very healthy.
Not for everyone of course for various reasons, but for the general population.
But it is good advice to watch going off of atkins for your pregnancy so you don't gain a lot of weight. (well, anymore than the pregnancy)