Zygote, Embryo or Fetus?If you are reading about your pregnancy, you may find that there are several labels given to the little human being living in your womb. One book says it’s a zygote, while others may refer to it as an embryo, and you may most frequently encounter the label “fetus”. Your baby is actually all three of these, but in different stages of his or her development. To clear the confusion, read on below: When is my baby a zygote? As you ovulate, one of your ovaries will release an egg cell into your fallopian tube. If your partner ejaculates during intercourse, millions of sperm cells will travel to meet your ovum, but only a few hundred will get close. The competition becomes tougher when it’s time to penetrate the outermost layer of the egg cell, because only one sperm cell will be able to achieve this. When successful, the union of the ovum and sperm is what is known as a zygote. This is known as fertilization, and it is not visible to the naked eye, nor can it be felt by the mother. What is an embryo? After the fertilization process is complete, the zygote undergoes several instances of cell division. What was formerly comprised of two cells now aggressively develop into a tiny, tiny group of cells. Cell division results to growth. At this point, the mass can be likened to a tiny blood clot. Too tiny – that it still cannot be felt by the mother. The fallopian tube continues to sweep the “clot” into the uterus, where it shall stay for the rest of the nine month period. When it implants itself to the wall of the womb, it begins to take from the mother, the nutrients it needs to grow further. Four weeks after fertilization, the zygote will now have formed more than three layers of cells, and is attached to the uterus. At this point, it is now an embryo. Its appearance can be likened to a tadpole – a large head, no limbs and a tail. It shall continue to develop organs and appendages for about ten weeks. At which stage can my baby be called a fetus? A baby is formally known as a fetus after ten weeks post-fertilization. This is when the baby has lost its “tail”, and has gained human-liked features like a face, arms, legs, and a trunk. The heart and brain are aggressively developing at this point, so are other vital organs. Gender may also be visible at this point. The fetus continues to develop more refined features, over the remainder of the nine months that he or she is in the womb. Read more of our articles on the first trimester
First Trimester Emotional and Physical Needs Read about the other trimesters |