Kids having kids — that sounds like a lurid tabloid headline, but sometimes, it really is true. Shockingly, children as young as age 5 have been known to get pregnant and give birth. Precocious puberty is a condition where a child’s body develops very early in life – before the age of 8 when it comes to girls. It’s not that uncommon. What’s uncommon is when someone takes advantage of that early onset of fertility and a baby is the result.