Gareth Peirce, her solicitor, told Bow Street magistrates' court that Ms McAliskey's medical needs had been ignored, despite the instructions of Ronald Bartle, the stipendiary magistrate, at her last appearance that she be well care for.
The doctor's report said that she showed signs of "advanced starvation" due to repeated vomiting, had no access to natural light and was in danger of losing her baby, Ms Peirce said.
The German government is seeking to extradite Ms McAliskey, the 25-year- old daughter of former nationalist MP Bernadette McAliskey, in the wake of the June mortar attack on British Army barracks in Osnabruck.
Ms McAliskey is being held as a high security prisoner at Holloway women's prison, north London. Her classification would mean she is subject to special supervision, "closed" visits through screens and restricted contact with other prisoners.
Mr Bartle said the medical report made "disturbing reading ... I commented on the last occasion that Ms McAliskey's condition should be properly provided for". But ordering that she stay in jail until her next appearance on 20 December, he said: "I feel that my public duty demands that I do not alter the previous ruling."
A Prison Service spokesman said Ms McAliskey was taken to a London hospital on 5 December and had a scan and full examination by a consultant obstetrician. "He confirmed that she was in good general health, that her 16-week pregnancy was progressing normally and that there was no cause for concern."Reuse content