Soldiers have surrounded the politician’s home claiming that he could incite his supporters if he leaves the compound.
Bobi Wine – who became famous as a musician – tweeted that the baby’s father had been blocked from going into the compound.
He added that they had run out of food and milk.
The 38-year-old politician ran for the presidency for the first in elections on 14 January. He lost to President Yoweri Museveni, who has led the country since 1986.
He claims that he was cheated out of victory, and accuses the president perpetuating electoral fraud.
But President Museveni said on Saturday that the poll could be the “most cheating-free” in the history of the country.