Week 18

From baby-gaga:

Your child is nearly half a foot long (CR measurements that is) and nearing a half pound (about 7 ounces). Their skin is now covered in a waxy substance known as vernix and their external genitals are now developed enough to be seen from an ultrasound. As for you, well, there's a good chance you've noticed some odd dark spots on your skin, which are a result of your body overproducing melanin.