Week 25. Eyelashes and eye colour. The way the sense of hearing develops
We know that after 25 weeks the child will have eyelashes. However, the eye colour is not fully developed. This is because some pigments need light to get completely formed. In fact, your baby’s eyes may change in the first weeks of life. Asians and Africans are born with brown or grey eyes and end up with dark or black eyes. The Caucasians are often born with clear eyes, but when they mature they will possibly end up with green or brown eyes. Before, we thought that eye colour was determined by a single gene. New research has shown that there are several genes, so it’s impossible to know what eye colour your baby will have by looking for the parents’ eye colour only.
The sense that develops from this week is hearing. The child is very isolated, but the sound waves travel faster in the amniotic fluid that passes through the air. As a result, your baby begins to hear the first sounds, especially your gurgling and the murmurs of your body. It will also hear the noises it itself produces, as the splashing in the amniotic fluid or the movement of liquids produced by the ultrasonic waves of ultrasound scans. Although ultrasounds are not perceived by the human ear, waves shake the bag of amniotic fluid and the baby can hear its sound. From the outside world, it may hear talks, strident noises and music. However, the sound of the mother will always be different from the rest because it travels through the fluids of the two bodies. This is one of the many explanations given to the special relationship between mothers and children from birth.
It will keep measuring around 22 centimetres but will approach a kilo.