Your baby at 21 weeks
By 21 weeks, your baby weighs around 350g. From about this stage onwards, your baby will weigh more than the placenta, which, until now, was heavier than your baby. The placenta will keep growing throughout pregnancy, but not as fast as your baby. Around this time, the baby becomes covered in a very fine, soft hair called lanugo. The purpose of this is not known, but it’s thought it may be to keep the baby at the right temperature. The lanugo usually disappears before birth.
You at 21 weeks
Your womb will begin to get bigger more quickly and you’ll really begin to look pregnant. You may feel hungrier than before – try to stick to a balanced, healthy diet in pregnancy, and make sure you know what foods to avoid when you’re pregnant.