The trikonasan helps strengthen the pelvic floor muscles , hips and thighs and this is definitely much needed during labor. It also opens up the chest and shoulders apart from easing the back. Added benefit is an improved digestion.
Disclaimer: All the exercises demonstrated in the videos need to be done under the supervision of a trained practitioner at the start, until one is proficient and comfortable to take these up individually. Even then, if at any moment there is any discomfort , one must stop and consult a trained practitioner.