Starting from the moment of conception, to the day you give birth, your baby undergoes various changes in the womb at different stages. Major developments continue to take place until the day he/she is born.
Pregnancy is categorised into three trimesters. During the first trimester, your baby goes from embryo stage to the fetus stage, with organs starting to build up. In the second trimester, facial features are formed and you may feel their movements. In the third trimester, the organs work on functioning and your baby gets ready for delivery.
By the end of week 12 in first semester, the baby is said to be formed with all the major organs, but more time is necessary for the organs to start functioning and be fully ready to function on their own after birth.
Fetal Developments Trimester-wise
This is the most crucial time for babies in the womb, because vital developments take place in the first three months. Babies grow from a mass of cells initially, to embryo and then to fetal stage. Baby’s heart beat can be heard by week 10 or 12, even though it begins to beat by week 6. Umbilical cord is formed. Baby’s brain, heart, lungs, digestive system and reproductive system develop during this time. Facial features also begin to take shape.
Muscles and bone developments take place, which enables the baby to move her limbs. You may be able to feel your baby move by this time. The movements become more pronounced as you move into next trimester. All the organs will be formed by the end of this trimester. Some babies may be born as early as 23 weeks, but they may develop many complications and require intense care and medical support.
You can feel a lot of movements by now. Her sense organs are well formed and she may be responsive to light and your voice. Her bones grow stronger. Blood circulation system is developed. Her respiratory system, nervous system and brain are at the end of their development process. As her lungs are ready to function, she may practice breathing on her own, which you may feel as baby hiccups. Her immune system and fat layer keeps growing till the end.
Most preterm babies develop breathing problems when they are born. This is because respiratory system functioning development keeps happening as long as the baby is in the womb. Babies born at the end of week 38 are said have the best chances of survival, without any health issues.