When this happens, the spirit which chose to reincarnate as a child is the aborted fetus in the other life who then creates the mothers’ suffering: in most cases energetic attacks of hurt , anger or revenge of the spirit rejected .
There are cases, however, where the mother and child form an agreement before the pre-chosen reincarnation, where both agreed to go through the experience of pregnancy; she may give birth to a child with physical disabilities, where the bonds of love, responsibilities and care are tested and healed for as long as they live.
But we may always remember that everything in the universe is in resonance within the parameters of divine justice, no action is aleatory or random.
The karma in question may have been individual or collective. An example of collective karma is the participants of the Catholic Inquisition in the Middle Ages, that together spread terror across the world, torturing and killing Jews, Muslims, “witches”, homosexuals and any who dared to think differently.
Consequently, as an organization now it has been suffering through many later incarnations of the victimized souls from problems and persecutions of sorts, on the physical level, and it will be as such until its karma is balanced and transmuted.