Every soon to be parents who are expecting their first child will be anxious about the development of their baby during the pregnancy period. Before it is born, the baby is known as a fetus, as human is classified under the mammal category. Fetus is a developing mammal in the stage of after embryonic and before birth stage. In humans, the stage of fetus development will begin on the 9th week after fertilization. In the fifth months, the fetus would have a fully developed bone and skeletal system but exactly how big is a fetus at 20 weeks?
There are variations in the growth of the fetus. Some of them will grow faster than the others compared to the diet of their mother. However, if some fetus who does not reach the expected size, it may suffers from a condition called fetal growth restriction. It is caused by several factors such as maternal, placental and fetal as well the diet of the carrying mother. Maternal factors will include things that affect the carrying mother, her body mass index, nutritional states, emotional stress and also toxin exposure. If the carrying mother is a drug abuser or a smoker, it will restrict the growing process of the fetus.
At 20 weeks, for a normal healthy and developing fetus, the lanugo will cover the entire body. The eyebrows, eyelashes, fingernails and toenails will be appears. The muscle will be well developed and the lungs will be formed. The nervous system will reach the stage where it is able to control some of the body function. At this stage, the cochlea will be developed as well. However, the neural portion of the auditory system will only be developed until they are 18 months. The respiratory system will now be able to exchange gas. It will start moving and the carrying mother will be able to feel the fetus kicking or movement in the stomach.
The fetus will reach about 20 cm, around 8 inches and will weight around 600 gram by the end of the 20 weeks.