Kenyan sand boas give live birth - they don't lay eggs. At the moment of birth the babies might still have some leftover of the egg yolk attached to them but these, and the cords, will get absorbed within a couple days and completely disappear.

Photo by Roy Stockwell

Here another shot of this sand boa giving birth. Notice how the mother becomes 'deflated' as the babies come out.

Photo by Roy Stockwell

Here a close-up of.

Photo by Roy Stockwell

And here another close-up of the mother Kenyan sand boa giving birth.

Photo by Roy Stockwell

Below you can see the difference between a Kenyan sand boa which gave birth and one which is still pregnant and will give birth within days. You can see how big the females get - in comparison with how much smaller the female gets after the fact. It is nearly impossible to mistake a pregnancy of a female Kenyan sand boa.

The female on the left is still due, and the one on the right just gave birth a couple days ago.

Ypu can start feeding the females a couple days after they give birth. It is better to start them on smaller items. Mine usually eat small rats, but I gave them three adult mice for their first meal.