The first of the numbers (rate of mothers dying) would not be affected at all by what you mention, and the second (rate of children under age of 5 dying), while

The first of the numbers (rate of mothers dying) would not be affected at all by what you mention, and the second (rate of children under age of 5 dying), while affected by infant mortality (number of deaths of infants under 1 year old), is a much wider metric, so the effect is also relatively small. Either way, I'd be interested in seeing some sources for those claims, as it's the first I've heard of it happening, at least in the developed world. And I mean it sincerely, since it's a topic of interest to me.