An Austin woman who allegedly caused life-threatening injuries to her 18-month-old was charged Thursday with first- and third-degree assault, both felonies.

Heang Kim Sean, 21, has denied causing the injuries to her daughter.

Court documents allege that Sean caused injuries to her daughter that included liver lacerations, bruising of the intestinal wall and spleen, pancreas damage and blood in the abdomen.

The child was in the hospital from Aug. 12 to Oct. 3, according to the complaint. In that time, she had a blood transfusion and surgery to remove a section of her small intestine.

Sean told police officers something must have happened to harm the child at daycare. However, she said the toddler “was great” and able to eat and play when she picked her up from child care just after midnight on Aug. 12, hours before she was taken to St. Marys Hospital.

The morning Sean took her daughter to the hospital, she said the child looked “pale, white, not normal and weak” when she checked on her, court documents stated.

A doctor at the hospital told officers it was highly unlikely the toddler would have been able to eat, drink or play with such severe injuries. The doctor said the injury could not have occurred without someone realizing the child was hurt, as she would have been in obvious pain, according to court documents.

“The medical records revealed the injuries received by the child would have taken extreme force, such as an automobile accident or a very hard blow to the abdomen by an adult,” the complaint stated.

Sean faces the termination of her parental rights for failing to protect her daughter, according to a family court petition. Mower County Human Services also petitioned for child protective services for Sean’s son, who was born in early October. Both children are in the custody of MCHS at undisclosed foster homes, according to the petition.

Sean’s third-degree assault charge stems from multiple fractures found on her daughter in May 2011. According to a family court petition, Sean told St. Marys Hospital staff the toddler had fallen from her bed onto the floor. However, Sean told a Mower County Sheriff’s deputy she may have been hurt at daycare by the dog or by an aggressive 2-year-old.

Deputies went to Sean’s home to view the bed from which the child allegedly fell. According to the petition, the “bed is a mattress placed directly on a carpeted floor. Mattress is reported to be eight to 10 inches off the carpeted floor.”

Later, Sean told the deputy the fractures occurred when she was playing with the child.

“The defendant stated that the child was trying to stand and she would push the child down and the child got ‘caught in the bed sheet,’” according to the complaint.

Court documents report St. Marys Hospital staff was concerned in May and August about Sean’s accounts of the toddler’s injuries.

A doctor at the hospital told law enforcement officers the child’s internal injuries were caused by major trauma. The court complaint said the doctor thinks it is a “strong possibility” the injury took place between 12:40 a.m. and 3 a.m. on Aug. 12 — from when Sean picked the child up from daycare to the time the child was put to bed.

Sheriff Terese Amazi said the investigation leading to Sean’s arrest was lengthy, especially because the infant is not old enough to provide an eyewitness account.

“We depend on doctors when the child can’t speak for themselves,” Amazi said.

Sean is not yet scheduled for her first court appearance.