In pregnancy week 21, your little one can weigh about 12.7 ounces and can be up to 10.5" in length. Your baby is still active moving in the amniotic fluid. But as this trimester ends, your baby will settle into a stable position, mostly with the head pointing downwards. There is a pattern to the movements, as your baby sleeps and wakes up at regular intervals, just like a newborn baby. Your baby's digestive tract, although has not completely matured, can carry out peristaltic movements by contracting and relaxing the intestinal muscles. Your baby continually takes in copious amounts of amniotic fluid and excretes urine. The swallowing of the amniotic fluid actually helps the intestines develop.
The other organs, the central nervous system and skin are also growing fast. The eyebrows, eyelashes and hair are growing. The lungs with the two bronchi and many bronchioles expand in size, and even some alveoli begin to form. Pregnancy week 21 is when the little one is able to differentiate between tastes.
Your little one is hiccupping in the uterus, in pregnancy week 21. This is not unusual. You will feel it, and may find it happening for several minutes at a time. Some babies hiccup at a certain time, some hiccup a few times a day, and some more frequently than others. Your baby hiccupping is quite a common occurrence and you need not worry about it. Some pregnant women also find the rhythmic movements of hiccupping very funny.
You are now feeling your baby's movements in this period, even more than before. You can actually know when your little one is snoozing and when he is not. Your baby also tends to sleep more when you are active, as your movements usually rock your little one to sleep.
In pregnancy week 21, you will notice some changes in your breasts which continue to enlarge. You may even find the appearance of colostrum, which is the first milk that is secreted, and which is highly beneficial for your baby, as it contains antibodies. The colostrum may stain your bra a bit yellow. If you find your bra stained, then this is a sign that your body has started to make colostrum.
You may begin to feel pain and aches in your legs, which is a common symptom of pregnancy. There are many accessories that you can use during pregnancy that will make you more comfortable, such as pregnancy stockings, belts and pillows. To help reduce the pain and aches, do exercises such as stretching your calves and rotating your ankles. For leg aches, always elevate your legs when sitting down.
In pregnancy week 21, your emotions are not as rife as earlier, because your hormones have balanced out. Your uterus apex, the fundus is now one inch above the belly button. Just make sure you eat all the right foods, drink lots of water and take rests often by putting your feet up.