20 weeks pregnant

How is your baby growing at 20 weeks?

Your baby is about 17cm from head to bottom (crown to rump) but the real change in your baby's size is in his or her weight, which should now be about 310g. Not only have the first set of milk teeth already formed in your baby, but the second set of permanent teeth should now be forming too.

Your baby should now be fully covered by the protective layer of white greasy vernix. Without it, constant exposure to the amniotic fluids could cause the baby's skin to harden or become chapped. Some of the vernix may be present at birth, especially in babies born early, and will need to be wiped off.

When you first notice your baby moving can depend on your baby's and the placenta's position. If the placenta or the baby's spine is at the front of your bump, it's usually more difficult to feel him or her moving. However, most mums-to-be should now begin to notice their baby moving, sometimes referred to as "quickening". You may have missed the earlier fluttering or rippling sensations – you might have mistook them for wind or indigestion – but now that your baby is getting stronger, you may feel a push, or perhaps the baby twisting about or kicking. For the next 4 weeks your baby will be increasingly more active, and a pattern may develop where he or she gets more active as the day goes on or just before or after a meal.

How are you changing in week 20?

You are now halfway through the pregnancy and the top of your womb may be at the same level as your belly button. You should be gaining rapidly in size during the next few weeks, when much of your growth occurs. It's likely that your bump will be increasing by 1–2cm a week.

A hormone known as relaxin is produced during pregnancy to help the ligaments in your pelvis and other joints to relax, in preparation for childbirth. This can lead to backache, which often appears between weeks 20 and 28. As the baby grows, you will also find that your back becomes increasingly stiff, making twisting at the waist and bending forwards more challenging. Taking care of your back will become increasingly important to avoid back pain, especially if you've had previous back problems.

Some women experience pain in the pelvis area due to the increased movements within the joints, possibly because the bones move unevenly. Pelvic pain can happen anytime during pregnancy. Pelvic pain is sometimes referred to as symphysis pubis dysfunction (SPD) or pelvic girdle pain (PGP). The pain may occur over the pubic bone in the front of the pelvis, across one or both sides of your back, or between your vagina and anus. While some women may have just mild discomfort, others may experience severe pain. Walking or going up stairs can make the pain more noticeable.