Nadia was delivered by caesarean section in the local maternity hospital in the Altai region on September 17, joining eight sisters and three brothers, a local reporter said.
"We were all simply in shock," said Nadia's mother, Tatyana Barabanova, 43. "What did the father say? He couldn't say a thing - he just stood there blinking."
"I ate everything, we don't have the money for special foods so I just ate potatoes, noodles and tomatoes," she told the reporter, adding that all her previous babies had weighed more than 5 kg.
The Guinness World Records lists a 10.2 kg baby boy born in Italy in 1955, and a 10.8 kg baby boy who was born in the United States in 1879 but died 11 hours later.
The average weight for most healthy newborn babies is around 7.06 lb, according to World Health Organisation figures.
