The incident took place at Kamla Raja Women Hospital last night.
"About 50 women, some of them pregnant and others under the post-operative care after delivery, reported shivering last night after they received ampicillin injections. Their attenders raised an alarm and we immediately took precaution to control the situation," Hospital Assistant Superintendent Rita Mishra said.
The condition of all the women, including five who remain admitted in the ICU, was stable, she said.
"There are allergic reactions due to the injection and further investigation is underway," she said.
More From This Section
She said the antibiotic was supplied by a government supplier and that the hospital had suspended the administration of the injection for now as a precaution.
"Samples of the injection would be sent for an examination," Mishra said.
Meanwhile, the Gwalior district administration ordered an inquiry into the incident.
An official said the inquiry was being conducted by Sanjay Chandel, Assistant Professor at the Gajra Raja Medical College, and Rajeev Singh of the Child Development Department.