Yes, these things do come up in therapy, very rarely but they do. I know this for a fact. I know people who had the memories of birth come up during therapy and they were confirmed as facts by their mothers who described what had happened during deliveries. The events they described were very consistent with the memories of their children that surfaced in therapy. Our bodies remember many things that our conscious minds can't remember, and from time to time those memories may become conscious remembrance, possibly at the times when we instinctively feel that it's safe to pull those experience into conscious awareness.