16 Weeks or 4 months, almost half way through the pregnancy. It is around now that you may start to feel your little one move.
The fetus is about 4.5 - 5 inches long now from head to rump and weighs about 100 grams. The baby's legs are longer than his arms at this stage. The circulatory system and urinary tract are in full working order and the fetus is inhaling and exhaling amniotic fluid in and out of it's lungs.
Your baby's eyebrows and eyelashes are starting to grow. If you could gently stroke your baby's cheek she would respond as if searching for a nipple to latch on to. Until now her head has grown quicker than anything. Now your baby's body accelerates to catch up and she begins to look more in proportion. Your baby will look thin because she hasn't developed a layer of fat, and her skin is so thin you can see the blood vessels below.
Your baby can suck her thumb and make a fist. The baby's eyelids will stay closed until about the 25th week, although your baby can detect changes in light through her thin eyelids. A fine covering of thicker, darker hair called languo starts to grow on your baby's body. This keeps your baby's body at a constant temperature in the absence of fat. Bones start hardening, including the tiny ones in your baby's ears, and your baby can hear some sounds for the first time.
Your uterus is growing rapidly to accommodate the growing baby. The top of your uterus is about halfway between your pubic bone and your navel. You may feel twinges in you lower abdomen, this is usually the ligaments that are thickening and stretching as the uterus grows.
It will not be long now before you will start to feel the first signs of your baby move. This is usually called "quickening". Some women feel this as early as 16 weeks but many do not feel any movement until around 18 weeks or more. The first sign of movements often feel like flutters or gas bubbles. These feelings will grow stronger and you will feel them more frequently as the pregnancy progresses.
Hopefully by now you should feel less nauseous, fewer mood swings. It is usually the middle of the pregnancy when you feel your best. Your skin retains fluid, making it firmer and smoother and an increase in blood flow can make your skin glow. To cope with the increased flow of blood throughout the body your heart rate increases by about 20 per cent. The increased circulation makes your hair and nails grow faster.
My Experience at 16 weeks
I had a bit more energy than usual this week and felt a bit more normal although I began to notice that some of the waistbands on my clothes were too tight for me. My breasts increased a lot in size and this week I had to start wearing a maternity bra. By the end of the day it was noticeable that I was pregnant as my lower abdomen seemed to swell up.