Over the course of your pregnancy, the fetus inside you will grow from a tiny little egg to a complete human being. The nine months it takes a baby to develop are an exciting time, both for you and for the fetus. Each month of your pregnancy will bring new developments to the fetus as well as new changes to your body.
What Happens in the First and Second Month
From the moment the sperm meets the egg, the baby’s gender is determined. About two weeks after the egg is fertilized, it will implant itself to the wall of the uterus. You may experience some bleeding at this point but will otherwise most likely not know you are pregnant. By the fourth week, the embryo will measure less than a 10th of an inch long and will begin to develop specialized cells.
During the second month, the embryo will start to develop its heart, digestive tract and brain. By the end of the second month, the embryo will be over a half an inch long. It will have started to grow legs, arms, eyes and ears.
Development in Months 3 and 4
The third month of pregnancy brings some exciting changes to the baby. By the middle of month three, the baby will no longer be an embryo but will be a fetus. It will be able to make a fist and will have fingernails. By the end of the month, the fetus’ body will be fully formed.
By the fourth month, the fetus should measure about 3 inches long. Its face will look like a human’s face, it will begin to grow hair and it will start to move noticeably. You will be able to hear its heartbeat during a doctor’s visit.
Months 5 and 6: The End of the Second Trimester
The fetus’ rudimentary lung system begins to function in the fifth month. The fetus grows to about 10 inches long by the end of the month and will weigh about half a pound. You will be able to feel the fetus moving inside you.
By the sixth month, the fetus will produce a film called vernix caseosa, which protects its skin. It will also be able to hear sounds and will react to them inside your uterus. At the end of the month, the fetus will weigh about one and a half lbs.
The Final Trimester
Your fetus will begin to sleep, wake and cry in the seventh month. Its eyes will open, and the fetus will be able to distinguish light.
In the eighth month, the baby’s lungs will be developed enough that it can breathe but will still not be fully formed. In this next-to-last month, the baby will gain a lot of fat and will nearly double in weight. The fetus will have less room to move, as it will fill nearly the entire uterus.
The Last Month
In the final month of pregnancy, the fetus begins to turn itself so that its head points towards your pelvis. Its skin becomes smoother and pink, and its lungs continue to become more developed. A baby born at any time during the ninth month will most likely survive on its own without an incubator.
Right before birth, the average baby weighs 7 lbs and measures about 20 inches long.
- baby image by Dron from Fotolia.com