16 weeks ~ 4 months along!
Baby O is busy!
Get ready for a growth spurt. In the next few weeks, your baby will double his weight and add inches to his length. Right now, he's about the size of an avocado: 4 1/2 inches long (head to rump) and 3 1/2 ounces. His legs are much more developed, his head is more erect than it has been, and his eyes have moved closer to the front of his head. His ears are close to their final position, too. The patterning of his scalp has begun, though his locks aren't recognizable yet. He's even started growing toenails. And there's a lot happening inside as well. For example, his heart is now pumping about 25 quarts of blood each day, and this amount will continue to increase as your baby continues to develop.
Not only is your baby growing, your uterus and placenta continue to grow to accommodate the growing baby inside of you! Just six weeks ago, your uterus weighed about 5 ounces. This week it now weighs 8.75 ounces! The amniotic fluid that surrounds the baby is increasing and there is about 7.5 ounces of fluid. You will easily be able to feel your uterus approximately three inches below your navel.