No existing evidence that showed any side effect on the fetus at this dose. on other had some studies demonstrated it usefulness in maintaining failing pregnancy , equally this is not supported by good quality data
the progesterone is the natural hormone in the pregnancy; its concentration cannot be too high. Besides, its natural endogenous serum concentration in pregnancy is at least 10ng per millilitre and the upper level in pregnancy is more than 100ng per millilitre. Therefore the oral application cannot significantly increase the progesterone concentration.