Week 5: What's happening this week

Our baby is about the size of a sesame seed, and he looks more like a tiny tadpole than a human. The big development this week: Our baby's brain is beginning to grow! It develops from the neural tube, a structure that will also spawn our baby's spinal cord, nerves, and backbone. Since folic acid helps prevent neural tube defects, you can see why it's so important early in pregnancy. In the meantime, the primitive placenta and umbilical cord, which deliver nourishment and oxygen to your baby, are already on the job.