Woman gives birth to twin sons 10 years apart

A woman has given birth to twin sons - 10 years apart. The woman gave to the twin brother of her son from an embryo that was frozen for 10 years.

Wang, from China, had been struggling to conceive a child. In 2009, she decided to try the in vitro fertilisation (IVF) treatment and doctors cultivated a "batch of embryos". They implanted one embryo into Wang in October of that year.

While Wang went on to give birth to baby 'Lulu' in June 2010, the doctors at Hubei Maternal and Child Health Hospital froze the rest of her eggs so that she could go through the process later.

About 10 years later, Wang (now 41) decided to have a second baby. When she returned to Director Xiao Mei, who helped her with her first pregnancy, the doctor recognised Wang immediately.

The hospital said that despite her age, Wang's pregnancy was "relatively smooth".

The woman welcomed her second son on June 16 after giving birth via cesarean. The baby who has been named Tongtong weighed 3.48 kilograms at the time of birth, exactly the same weight as that of his elder twin brother.

Human Fertilisation and Embryology Authority in the UK explains that there may be good quality embryos left over after the IVF treatment. Instead of discarding them, those embryos can be frozen to use in the future, in case the first treatment doesn't work. They can also be frozen to preserve fertility to try for a sibling at a later date.

"From a medical perspective, Lulu and Tongtong are twin brothers," Zheng Jie, a doctor from the fertility centre of the hospital, said.

"The same doctor did the test tube operation, the same doctor did the cesarean section operation, the two babies were the same batch of embryos, the same sex, the same weight, were also born in June," the hospital said, adding that the twins born 10 years apart have so much in common that it's "extremely rare".