One of the most miraculous areas of science is that of the creation of life – all life. For this quiz, however, we are going to focus on the growth and development of human life from conception to birth. What size is a baby (fetus) after 6 weeks of conception? How about after 20 weeks?
At what stage are limbs formed, skin, lungs, eyes, heart and so on. It’s pretty amazing considering all humans start out at the size of a tip of a needle. In humans, a baby is considered full term at 38 weeks from conception. That means about 9 1⁄3 months. However, babies can be born between 37 weeks from conception up to 42 weeks.
Below are some vocabulary words that you need to know. (Yes, you read that right – vocabulary words!) before you continue with this introduction.
The Embryo
As you learned below, the embryo is the name given to a fertilized egg after it attaches to the uterus of the mother. The embryo has 3 layers of tissue
- Layer one becomes the baby’s blood, vessels, bones, muscles and skin.
- Layer two becomes the respiratory system and the digestive system.
- The third layer becomes the baby’s nervous system.
The Placenta
Again, as you learned below, the placenta is a sac of blood vessels. It develops during the third and fourth week from conception and connects the baby to the mother. It serves as the baby’s kidney, lungs and intestines.
The Umbilical Cord
The umbilical cord is a bundle of 3 vessels. Two vessels bring oxygen and nutrients to the fetus. The third vessel removes carbon dioxide and waste from the fetus which is then absorbed into the mother’s blood.
Now let’s see how the embryo develops into a fetus and then into a baby.
Fetus Development Stages
- At 6 weeks - fetus (baby) is about a ½” long
- At 9 weeks - fetus (baby) now looks like a baby and all of its major organs have been established
- At 12 weeks - baby weighs one ounce and is 3 inches long (generally by the 12th week after conception the fetus is now referred to as a baby)
- At 16 weeks (4 months) - baby is nearly 6 inches long and is in a sitting position in the womb
- At 5 months - baby is 10 inches long
- At 6 months - baby hears, notices and recognizes sounds
- At 7 months - baby can open his/her eyes, though they cannot see yet, and his/her brain develops to control breathing and swallowing (though the baby doesn’t breathe on its own yet). Baby can also get hiccups
- At 8 months - baby’s fingernails finish forming and he/she turns in the womb downward to get ready for birth
- At 9 months - baby is born
The birth of a baby is a wondrous time! It’s hard to believe that 9 months earlier, it was the size of a pinhead. Do you know how much you weighed when you were born? Most babies, though not all, when they are full term will weigh between 5lbs and 8lbs. So the next time you meet someone who is expecting – ask them how far along they are and you will be able to tell just what the baby might weigh and look like as far as its development!
Now, let’s see what you can remember without looking back at this introduction. Take the following quiz and see how high you can score!
