Expectant mothers are asking doctors to deliver their babies prematurely, via Caesarean section, so they can be born before the end of the lucky "Year of the Golden Pig," Vietnamese doctors said Thursday. Vietnam, which traditionally follows the Chinese lunar calendar, will celebrate its New Year, known as "Tet," on February 7.

According to the Chinese zodiac, the past year has been an especially lucky Year of the Pig, and babies born in this year are believed to enjoy good fortune.

"The number of pregnant women requesting C-sections has risen sharply recently, though they don't have any problems with their pregnancies, and they are due to deliver after Tet," said Dr Le Thanh Thuy of Hanoi Obstetric Hospital. "The women do not say why they want a C-section, but we all know they want their babies to be born before the end of the Year of the Golden Pig."

This year has witnessed an explosion in births, as Vietnamese couples rushed to have lucky children.

Dr Nguyen Viet Tien, director of the National Obstetric Hospital in Hanoi, said some 20,000 babies were born in the hospital in 2007, up 17 per cent over the previous year.

Tien said his hospital, too, was seeing many pregnant women requesting C-sections in order to have babies before Tet. Doctors are required to reject the requests due to the danger to the child.

"Having a C-section before it is due is like having a premature birth," Tien said. "Most of the women understand the danger, but they may be under pressure from their husbands' families."

31-year-old Bui Van Anh was one of the lucky ones. She gave birth to a baby boy, naturally, at noon on Thursday, a week before the Golden Pig deadline.

"Of course I'm happy," Anh said. "I think every mother wants to give birth naturally."

The dilemma is made even sharper because the expected decline in good luck after the upcoming Tet is particularly dramatic.

"Next year is the Year of the Rat," said Dr. Thuy. "It is not considered to be good."

Nevertheless, Anh she said she would not have asked for a C-section if she had been due after February 7.

"You cannot choose your baby's fate by choosing a day for its birth," Anh said.