THE X-FILES actress Gillian Anderson is celebrating becoming a mum for the second time, after giving birth to premature baby boy OSCAR. The 38-year-old welcomed her six pound eight ounce son into the world at London's exclusive Portland Hospital on 1 November (06), three weeks before he was due. Anderson and her boyfriend MARK GRIFFITHS have only just publicised the birth because they wanted to wait until Oscar was out of intensive care. Her spokesman says, "Both mother and baby are doing fine now." Anderson already has a 12-year-old daughter, PIPER MARU, from her relationship with The X-Files art director CLYDE KLOTZ.