Tatiana Santo Domingo, the daughter of the late Colombian businessman Julio Mario Santo Domingo, Jr. and Brazilian socialite Vera Rechulski, has announced she is pregnant with her fiancé.

The 28-year-old socialite heiress is also the granddaughter of Julio Mario Santo Domingo, Sr., who Forbes named Colombia’s second richest man in 2011.

The baby’s father is Andrea Casiraghi, 28, the eldest son of Caroline, Princess of Hanover. He is second in the line of succession to the Monegasque throne (Monaco) after Prince Albert II, his uncle.

Should Prince Albert II die without legitimate children, Casiraghi would likely adopt the surname Grimaldi and someday become the Prince of Monaco, after his mother Caroline.

In 2011, Santo Domingo launched, in partnership with Dana Alikhani, the Muzungu Sisters fashion venture, which focuses on ethical business practices that allow them support local craftsmen, buy handmade garments at a fair price and then sell them.

Santo Domingo and Casiraghi announced they were expecting at the 2012 Telva de Moda Awards in Spain. Santo Domingo is in her sixth month of pregnancy.

They also plan to marry in 2013.