Fetal development is the process by which a human embryo transforms into a fully developed baby. This journey begins at conception, when a sperm fertilizes an egg, forming a zygote. Over the next nine months, the zygote undergoes rapid cell division and differentiation, developing into an embryo and then a fetus.
During the first trimester, the foundations of all major organs and structures are established. The heart begins to beat, and the brain, spinal cord, and other vital organs start to form. By the end of this period, the embryo is termed a fetus.
In the second trimester, the fetus continues to grow and develop. This is a period of rapid growth for bones and muscles, and the fetus starts to move and can respond to external stimuli. The senses begin to develop, and distinct facial features become visible.
During the third trimester, the fetus gains weight and the organs mature. The brain develops further, and the lungs prepare for breathing outside the womb
