MEXICO CITY (Reuters) - A woman who caused a sensation earlier this year when her doctor said she was pregnant with nine babies gave birth on Saturday to six, hospital officials in Mexico City said. "At 2:30 pm (2030 GMT) she gave birth to six babies, three boys and three girls," said hospital spokeswoman Maria Eugenia Gutierrez. "All are in good health." Doctors originally thought Cristina Hernandez, 28 and already the mother of a 10-year old girl, was carrying nine fetuses, but later they said subsequent tests showed seven. However, a hospital spokeswoman told Reuters on Saturday that Hernandez had given birth to six babies in all. "The impression there were seven came from a little shadow on the ultrasound image," said spokeswoman Maureen Garibay, adding that the babies were delivered by Caesarean section. Born three months premature, all are in incubators and the mother is well although still in intensive care, she added. Hernandez, a factory worker from the northern state of Chihuahua, told Reuters in an interview two weeks ago that she had been fired from her job for getting pregnant, and her enlarged family would have to survive on her husband's salary of $140 a month. Several firms have offered her free diapers, milk and vitamins to help her out, she said. The couple began fertility treatment in 1995 in an attempt to have a second child. Hernandez would have been only the second Mexican woman to give birth to septuplets, if that estimate had proved correct. All of the septuplets in the previous case died shortly after birth, in January last year. It was not immediately clear whether there have been other cases of sextuplets in Mexico. Hernandez's daughter, Selene, was awaiting the arrival of her new brothers and sisters at home in Chihuahua, Garibay added.