Duke cites the instance of a woman who supposed that she was not pregnant up to the night of her miscarriage.

She had menstruated and was suckling a child sixteen months old.

During the night she was attacked with pains resembling those of labor and a fetus slipped into the vagina without any hemorrhage; the placenta came away directly afterward.

In this peculiar case the woman was menstruating regularly, suckling a child, and at the same time was unconsciously pregnant.
Isham speaks of a case of unconscious pregnancy in which extremely small twins were delivered at the eighth month.

Fox cites an instance of a woman who had borne eight children, and yet unconscious of pregnancy.