During the nine-month process of conception to birth, the miracle of life takes a small group of cells and grows it into a new person! Understanding the different stages of pregnancy will help you identify the radical changes your body will go through during this time.
First Trimester (Week 1–Week 12)
After the first four weeks of pregnancy, your baby goes from a fertilized egg to an embryo. By week four, the baby’s heart begins to form, and the limbs start to show. Notably, at this point, the embryo is only one-twenty-fifth on an inch long; for a better perspective, that’s about six times smaller than the average housefly.
By week eight, all major organs and external body structures have started to form, and the heartbeat now works at a normal beat. The embryo has become a fetus, and the sex organ has begun to grow. Another significant change that happens is that limbs continue to grow and take shape, and the umbilical cord is developing, becoming visible. The fetus is only close to an inch long and weighs less than one-eighth of an ounce.
Week 12 is a seminal milestone because as the sex organ grows, you can learn the sex of your baby. At this point, your baby is around three inches long and weighs close to an ounce. The fetus can even make a fist as the nerves and muscles start to work together.
Second Trimester (Week 13–Week 28)
Welcome to the halfway point! Once week 20 rolls around, your baby will begin moving around, and you might feel some fluttering. At this point, the baby has eyebrows, eyelashes, fingernails, and toenails. It can hear and swallow as well. Also, the baby becomes covered by lanugo—a fine hair—and—vernix—a waxy coating. Both protect your baby’s skin forming underneath. The baby is now about six inches long and weighs only nine ounces.
At week 24, your baby’s bone marrow begins making blood cells. The baby develops lungs, even though they aren’t working. The baby also starts sleeping and waking regularly. The baby has grown to near a foot and weighs about one and a half pounds.
Third Trimester (Week 29–Week 40)
During week 32, your baby now has fully formed bones, even if they are soft. The baby can also open and close their eyes. The lungs haven’t finished growing, but the baby will start practicing breathing. They can now store vitamins, which is good because they grow quickly, about one-half pound a week.
Upon week 39, all organs are ready to function, and your baby is at full term. Your baby is ready to meet you!
Now that you understand the different stages of pregnancy, you are more prepared for the next nine months.