Heidi Murkoff from the beloved “”What to Expect”” series discusses your baby’s development at 5 weeks pregnant.
Your baby is the size of an orange seed (how fast they grow!). His or her’s heart and circulatory system are already forming, while the hCG hormone levels in your body are now high enough to confirm that you’re expecting using a home pregnancy test.
Welcome to week five of your pregnancy, the beginning of your second month. Hey! Only seven more to go! Your pregnancy is still new, but that embryo inside of you is growing fast and furious from the size of a poppy seed last week to as big as an orange seed right now – around 1/20 of an inch. Still pretty small, but a lot bigger than it’s been – and getting bigger every day!
Wondering what your growing baby looks like now? Actually, not much like a baby. Your little one has elongated from a ball of cells to a teeny tadpole-like shape, with a distinguishable head and, believe it or not, a tail. Not to worry, though. That tail will disappear soon enough, and a cute little baby bottom will take its place.
This week, a primitive heart begins to form and beat, pumping blood through your embryo’s emerging shape. The heart comes first because blood flow is essential. Without that blood flow, organs and the digestive and nervous systems won’t be able to form. At this early stage the design of the micro heart is still pretty rustic, with only two tubes pumping to a really unrhythmic rhythm. The heart won’t be fully functional until those tubes fuse together and the heartbeats coordinate, activity that requires a brain!
Fortunately, your baby’s brain is well past the blueprint phase. The neural tube, which will ultimately become baby’s spinal cord and brain, is under construction. And if that’s not enough bodybuilding going on, a rudimentary digestive system is taking shape, too. There’s a tube extending from the mouth to the tail of the embryo – and this tube will eventually turn into the stomach, liver, pancreas, and intestines.