In police affidavits released after his arrest, Knight told police that she became pregnant by Castro several times and each time he forced her to abort by starving her for weeks and then punching her in the stomach.
Officers today said that it went beyond punching, saying the Castro would jump on her and kick her in the stomach and once pushed her down the stairs to force a miscarriage.
Dr. Gerald Maloney was ER doctor when the women were hospitalized after their rescue and said that Knight appeared to be suffering from malnutrition.
All three girls were upset, he said.
"Michelle in particular appeared very upset and did not want a male doctor or nurse" taking care of her, Maloney said. Female staff were brought in to examine and care for her, the doctor said.
Documents released Wednesday by prosecutors revealed that there is a federal probe into thousands of dollars in Social Security checks cashed in Knight's name while she was a hostage.
The Social Security checks are believed to Supplemental Security income provided for adults and children with low income and who have disabilities.
Knight was described by family members as having a mild disability and was the mother of a young son at the time of her disappearance.