Anna Kournikova managed to keep her pregnancy "completely secret" by being "very undercover".
The 36-year-old former tennis player and her partner Enrique Iglesias, 42, are said to have become parents to twins, a boy, Nicholas, and a girl, Lucy, over the weekend, after managing to keep her pregnancy "completely secret".
A source said: "I saw her cute belly. A friend told me like five months ago [that] they were pregnant but keeping it very, very undercover.
"They basically only hang out with family and very close friends.
"They mostly keep to themselves."