Juan Francisco Gonzalez smiles during a news conference after his wife gave birth to sextuplets in the Mexico Hospital in San Jose May 18, 2015. The first sextuplets in the history of Costa Rica were born on Sunday night, according to hospital deputy director Juan Ugalde. The babies - four boys and two girls - were born premature, according to local media. REUTERS/Juan Carlos Ulate

Juan Francisco Gonzalez speaks to journalists after his wife gave birth to sextuplets in the Mexico Hospital in San Jose May 18, 2015. The first sextuplets in the history of Costa Rica were born on Sunday night, according to hospital deputy director Juan Ugalde. The babies - four boys and two girls - were born premature, according to local media. REUTERS/Juan Carlos Ulate

Juan Francisco Gonzalez speaks during a news conference after his wife gave birth to sextuplets in the Mexico Hospital in San Jose May 18, 2015. The first sextuplets in the history of Costa Rica were born on Sunday night, according to hospital deputy director Juan Ugalde. The babies - four boys and two girls - were born premature, according to local media. REUTERS/Juan Carlos Ulate

Dutch farmer Joke de Groot holds a one day old lamb near five others and the mother at a sheep farm in Herwijnen the Netherlands, March 1, 2007. Lamb Sextuplets are extremely rare and seldom survive birth. They need to be hand fed because the mother can only feed two or three lambs leaving the weaker one to die. REUTERS/Michael Kooren (NETHERLANDS)

Dutch farmer Joke de Groot feeds a one day old lamb near five others and the mother at a sheep farm in Herwijnen the Netherlands, March 1, 2007. Lamb Sextuplets are extremely rare and seldom survive birth. They need to be hand fed because the mother can only feed two or three lambs leaving the weaker one to die. REUTERS/Michael Kooren (NETHERLANDS)

Dutch farmer Joke de Groot feeds a one day old lamb near five others and the mother at a sheep farm in Herwijnen the Netherlands, March 1, 2007. Lamb Sextuplets are extremely rare and seldom survive birth. They need to be hand fed because the mother can only feed two or three lambs leaving the weaker one to die. REUTERS/Michael Kooren (NETHERLANDS)

Dutch farmer Joke de Groot feeds a one day old lamb near five others and the mother at a sheep farm in Herwijnen the Netherlands, March 1, 2007. Lamb Sextuplets are extremely rare and seldom survive birth. They need to be hand fed because the mother can only feed two or three lambs leaving the weaker one to die. REUTERS/Michael Kooren (NETHERLANDS)

Doctor Liz Whynot (L) and Doctor Brian Lupton talk at a news conference at the BC Women's Hospital to discuss the birth and care of sextuplets in Vancouver, British Columbia January 8, 2007. A woman gave birth to six babies at a hospital in Vancouver, the first time sextuplets are believed to have been born in Canada, local media reported. REUTERS/Andy Clark (CANADA)

Doctor Liz Whynot (L) and Doctor Brian Lupton talk at a news conference at the BC Women's Hospital to discuss the birth and care of sextuplets in Vancouver, British Columbia January 8, 2007. A woman gave birth to six babies at a hospital in Vancouver, the first time sextuplets are believed to have been born in Canada, local media reported. REUTERS/Andy Clark (CANADA)

Doctor Liz Whynot (L) and Doctor Brian Lupton talk at a news conference at the BC Women's Hospital to discuss the birth and care of sextuplets in Vancouver, British Columbia January 8, 2007. A woman gave birth to six babies at a hospital in Vancouver, the first time sextuplets are believed to have been born in Canada, local media reported. REUTERS/Andy Clark (CANADA)

People walk past signs to the hospital in Vancouver, British Columbia, January 8, 2007, where a woman gave birth to six babies, the first time sextuplets are believed to have been born in Canada. REUTERS/Andy Clark (CANADA)

A female white Bengal tiger, named Betty, stands with her cubs in a cage at Buenos Aires' Zoo, in Argentina, January 6, 2004. The tiger gave birth to six cubs on November 18, 2003, each of which weighed about one kilogram and could weigh 270 kilos (723 pounds) at the age of 15. It's the first time in South America that sextuplet tigers have been born.

White Bengal tiger cubs play in a cage at Buenos Aires' Zoo, in Argentina, January 6, 2004. A female white tiger named Betty gave birth to six cubs on November 18, 2003, each of which weighed about one kilogram and could weigh 270 kilos (723 pounds) at the age of 15. It's the first time in South America that sextuplet tigers have been born.

Three white Bengal tiger cubs play in a cage at Buenos Aires' Zoo, in Argentina, January 6, 2004. A female white tiger named Betty gave birth to six cubs on November 18, 2003, each of which weighed about one kilogram and could weigh 270 kilos (723 pounds) at the age of 15. It's the first time in South America that sextuplet tigers have been born.

A female white Bengal tiger, named Betty, holds up one of her cubs in a cage at Buenos Aires' Zoo, in Argentina, January 6, 2004. The tiger gave birth to six cubs on November 18, 2003, each of which weighed about one kilogram and could weigh 270 kilos (723 pounds) at the age of 15. It's the first time in South America that sextuplet tigers have been born.]

A female white Bengal tiger, named Betty, stands with her cubs in a cage at Buenos Aires' Zoo, in Argentina, January 6, 2004. The tiger gave birth to six cubs on November 18, 2003, each of which weighed about one kilogram and could weigh 270 kilos (723 pounds) at the age of 15. It's the first time in South America that sextuplet tigers have been born. REUTERS/Marcos Brindicci MBH/GAc

White Bengal tiger cubs play in a cage at Buenos Aires' Zoo, in Argentina, January 6, 2004. A female white tiger named Betty gave birth to six cubs on November 18, 2003, each of which weighed about one kilogram and could weigh 270 kilos (723 pounds) at the age of 15. It's the first time in South America that sextuplet tigers have been born. REUTERS/Marcos Brindicci MBH/GAC

Argentine children look at a white Bengal tiger cub at Buenos Aires' Zoo, January 6, 2004. A female white tiger named Betty gave birth to six cubs on November 18, 2003, each of which weighed about one kilogram and could weigh 270 kilos (723 pounds) at the age of 15. It's the first time in South America that sextuplet tigers have been born. REUTERS/Marcos Brindicci PP04010015 MBH

Three white Bengal tiger cubs play in a cage at Buenos Aires' Zoo, in Argentina, January 6, 2004. A female white tiger named Betty gave birth to six cubs on November 18, 2003, each of which weighed about one kilogram and could weigh 270 kilos (723 pounds) at the age of 15. It's the first time in South America that sextuplet tigers have been born. NO RIGHTS CLEARANCES OR PERMISSIONS ARE REQUIRED FOR THIS IMAGE. REUTERS/Marcos Brindicci PP04010015 MBH/GAC

A female white Bengal tiger, named Betty, holds up one of her cubs in a cage at Buenos Aires' Zoo, in Argentina, January 6, 2004. The tiger gave birth to six cubs on November 18, 2003, each of which weighed about one kilogram and could weigh 270 kilos (723 pounds) at the age of 15. It's the first time in South America that sextuplet tigers have been born. REUTERS/Marcos Brindicci MBH/GAC

A Pakistani nurse tends to one of the sextuplets born inside an
intensive care unit of Al-Shifa International Hospital in Islamabad
November 1,2002. Nusrat Hafeez, 48, wife of Hafeez Sheikh, former
councillor from Pakistan's Punjab city of Faisalabad, gave birth on
late Wednesday through ceasarean section to six pre-mature babies, five
girls and a boy, after 17 years of marriage. REUTERS/Faisal Mahmood

MK/CP

From L-R: Melanie, Doriane, Coralie, Ga?lle, C?dric and K?vin seen with a birthday cake with their names and nine candles as they prepare to celebrate their birthday, January 14. The French sextuplets, four girls and two boys, celebrate their ninth birthday near Rouen in northwestern France.

Beverly and Rocco Boniello of Queens, New York, stand together at University Medical Center in Stony Brook, N.Y., April 5 with their sextuplets (L-R) Trifon Robert, Olivia Fredericka, Sabrina Juliet, Gerard Martin, Sofia Betty and Stella Raquel. The babies were born March 24. The mother had been taking the fertility drug Metrodin.

Beverly and Rocco Boniello of Queens, New York, stand together at University Medical Center in Stony Brook, N.Y., April 5 with their sextuplets (L-R) Trifon Robert, Olivia Fredericka, Sabrina Juliet, Gerard Martin, Sofia Betty and Stella Raquel. The babies were born March 24. The mother had been taking the fertility drug Metrodin. wlm/Pool photo by J.

SEXTUPLETS