Thanks Gordon,
Thanks Peter,
Thanks gentle yogini,
As per American Pregnancy Association advocate yoga as a stress-relieving, body-friendly means of exercise during pregnancy.
I found below poses which should be avoided for the safety of the mother and fetus during pregnancy.
Inverted Poses:
Poses that place the head below the heart should be avoided during pregnancy. Such as headstands, handstands and shoulder stands.
Because this positioning creates reduced blood circulation to the uterus and developing fetus.
Back Bends:
Back-bending poses such as upward-facing-bow or upward-facing-dog are designed to stretch and expand the abdomen, these should be only practiced WITH MODIFICATIOM.
Prone Poses:
Poses such as cobra, bow pose or locust–in which the majority of body weight is centered on the abdomen should be avoided after the first trimester, or earlier if pregnant women feel any discomfort in the pose.
In order to protect the developing fetus, women shouldn’t practice these poses because these poses place women in a prone position on their bellies.
Supine Poses:
Any exercise executed in the supine position is contraindicated after the first trimester.
This positioning is associated with decreased cardiac output in the mother, which in turn decreases blood flow to the fetus. Because, this positioning is deeply associated with decreased cardiac output in the mother, which in turn decreases blood flow to the fetus.
Twists:
Any traditional twisting poses such as the seated Marychiasana or the standing rotating triangle pose that because the spine to rotate extensively and compress the abdomen should not be practiced during pregnancy without modification.
Also, pregnant women tend to experience lower blood pressure so whatever Yoga exercise they perform should be performed in a group or under experts/teacher guidance.