Bridge Pose: You will wait at least 24 weeks before you begin to do work like this. Although this is classified as a back bend and you will be advised from doing back bends, the way we have this set up takes the "bend" out of the back and allows you to effectively use the power of your legs and gluts to help you connect to your core.
Kneeling Half Moon: When you are limited in working your front body core this is a great alternative, as well the forearm side plank. Here you will engage your outer hips and transverse abdominal muscles to sustain your balance. A great pose during and after pregnancy!