Fetal Development Week 12

This week is a big one for your fetus, as your little one learns what it means to respond reflexively. As those reflexes develop, your baby’s tiny hands will open and close, toes will curl, eyelids will clench, and that small mouth will begin to suck. In fact, if you gently prod your abdomen now, your little one will squirm, although you still won’t be able to feel his or her response! Equally exciting this week is the official functioning of your baby’s kidneys. As your baby swallows nutrient-rich amniotic fluid, those kidneys will convert it to urine, which will be sent to the bladder. And your fetus grows to slightly more than two inches by the end of week 12, meaning that your future baby is now officially the size of a small lime. This growth means that your fetus’s intestines—which previously protruded into the umbilical cord—can now begin to move into the abdomen. In addition, vocal cords are now fully developed this week, which, incidentally, is the last week of your first trimester. To see what’s up for the beginning of your second trimester, check back next week for your latest video update!