From 45 Days to 24 Weeks: Baby Development Inside the Womb These two visuals show how a baby develops inside the womb at very different stages of pregnancy. At 45 days, the fetus is still very small, but key features like the eyes, ears, nose, hands, legs, and umbilical cord are already forming. By 24 weeks (sixth month), the baby has grown significantly, with clearer facial features, stronger limbs, and more coordinated movements. The placenta, umbilical cord, and amniotic sac work together to