Bend it over

Some benefits of Vajrasana pose yoga also include:
aiding in digestion.
relieving or preventing constipation.
strengthening pelvic muscles.

Balancing table pose. From all fours stretch your right leg back behind you and reach your left arm forward hold for 3 to 5 breaths and then alternate. This pose requires core strength to maintain balance so it is good for working those abdominal muscles which will be important during labor.

The benefits of baddha konasana:
Strengthens and improves flexibility in the inner thighs, groins and the knees.
Helps prepare the hips and groins for meditative seated poses which require more flexibility in these areas.
Helps to sooth menstrual discomfort and digestive complaints.

Goddess pose opens your hips and chest and helps strengthen the lower body which helps get you in shape you for active labour. Make sure you draw up the muscles of your pelvic floor and lengthen your spine to see the benefits. Looking for a natural pain reliever during childbirth.