The youngster, who has not been named, had been accompanied by the 40-year-old man and another woman who claimed to be her mother-in-law.
The three arrived at the Xuzhou City Central Hospital, in East China's Jiangsu Province, claiming that the girl was three months pregnant and that she needed a routine test to confirm that her foetus was healthy.
The husband and mother-in-law said the wife was 20 years old, but medics immediately alerted local authorities when they found the young patient to be more like a schoolgirl than a "woman".
Doctors who tried to question the girl were unable to get any answers from her, as she did not speak any Mandarin.
Their suspicion is also said to have angered the husband, who was quoted as saying: "I took her here to be examined - just do your job. Stop asking so many questions."
Arriving police officers found that the girl did not possess a Chinese ID and concluded that she was a foreign national from Southeast Asia, but her exact origins are still unclear.
Investigators suspect that she was abducted or bought as a foreign bride - the Chinese have a history of purchasing Vietnamese brides from across the country's southern border.
Further investigation is now under way to determine the facts.
