You are now 19 weeks pregnant which is the beginning of week 20. Week 20 is seen as the 'half way' point in a standard 40 week pregnancy. Your baby now measures about 22 cm from head to toe (or 8.8 inches) and weighs about 340 grams (or 12 ounces). Most women look obviously pregnant by now and may need to start wearingmaternity clothes. You may also find you can't 'bend over in the middle' because your bump gets in the way!
By 20 weeks, if you feel the top of your uterus (or 'fundus') while lying down, it should be around about the level of your belly button. Many women will feel their baby move by now, but if the placenta is in an 'anterior' position (or implanted at the front of your uterus closest to your belly), this may blunt the sensations and delay you feeling them until about 22 weeks or more.
By 20 weeks, your baby is legally regarded as a person. In Australia, babies born before 20 weeks gestation (or weighing less than 400 grams) are regarded as being miscarried, but babies born after 20 weeks gestation (or weighing more than 400 grams) are regarded as being premature. (Other countries can vary from this classification. For example, the World Health Organization suggests 22 weeks and 500 grams in birth weight). Babies born at 20 weeks are medically regarded as 'extremely' premature and cannot survive. Technological advances have savedpremature babies as young as 24 weeks, but their chances of survival are greatly enhanced if born after 28 weeks.
During the 20th week, your baby's nails form and their fingerprints are now visibly engraved in their fine skin. Their permanent teeth now appear behind their baby teeth deep within their gums. The bones in your baby's inner ear and their nerve endings are now developed to the point where it is possible for them to hear sounds (although their ears are not structurally complete until 24 weeks). Studies carried out on the reactions of unborn babies to sound have shown that a few babies will start responding to noise as early as 19 weeks, but by 26 weeks all babies will respond. The sounds an unborn baby can hear include their mother's heartbeat and breathing, the wind sounds from her intestines and the sound of her voice, as well as other sounds around her. It is thought that if a pregnant woman is constantly exposed to loud noises, this may have an adverse effect on her baby's hearing.