By the time you're 17 weeks pregnant, your baby is growing quickly, and now weighs around 150g. The body grows bigger so that the head and body are more in proportion.
The face begins to look much more human, and eyebrows and eyelashes are beginning to grow. Your baby's eyes can move now, although the eyelids are still shut, and the mouth can open and close.
The lines on the skin of the fingers are now formed, so the baby already has his or her own individual fingerprints. Fingernails and toenails are growing and the baby has a firm hand grip.
The baby moves around quite a bit, and may respond to loud noises from the outside world, such as music. You may not feel these movements yet, especially if this is your first pregnancy. If you do, they'll probably feel like a soft fluttering or rolling sensation.
Your baby is putting on a bit of weight but still doesn't have much fat so if you could see your baby now it would look a bit wrinkled, although it will continue to put on weight for the rest of the pregnancy and will "fill out" by the last few weeks before birth.
By 20 weeks your baby's skin is covered in a white, greasy substance called vernix. It's thought that this helps to protect the skin during the many weeks in the amniotic fluid.
At 20 weeks pregnant, you're halfway through your pregnancy. You will probably feel your baby move for the first time when you're around 17 or 18 weeks pregnant. Most first-time mums notice the first movements when they are between 18 and 20 weeks pregnant. At first, you feel a fluttering or bubbling, or a very slight shifting movement, maybe a bit like indigestion. Later on, you can't mistake the movements and you can even see the baby kicking about. Often you can guess which bump is a hand or a foot.
You may develop a dark line down the middle of your tummy and chest. This is normal skin pigmentation as your tummy expands to accommodate your growing bump. Normal hair loss slows down, so your hair may look thicker and shinier.
You'll be offered an anomaly scan when you are 18 to 20 weeks pregnant – this is to check for abnormalities in the baby. Your midwife or doctor can give you information about this and answer any questions. You can find out more about screening for foetal abnormality.
Common minor problems can include tiredness and lack of sleep. Sleeplessness is common, but there is plenty you can do to help yourself sleep, including using pillows to support your growing bump. Some women also get headaches. Headaches in pregnancy are common, but if they're severe they could be a sign of something serious.