Pregnancy Help Center

of Smith County

A Christ Centered Ministry

i want to know more about fetal development

​​Let's figure out how far along you may be..... this is called the Gestational Age of your baby. What is the first day of your last menstrual period? From that date, you will count the number of weeks until today's date. That is approximately how far along you are in your pregnancy. Based on this information, your baby will be due 40 weeks from the first day of your last period. (For example, if your last menstrual period began October 31, 2014, and today is November 26, 2014, you would be 4 weeks and 4 days in gestation, with the baby's due date of August 8, 2015.)


Conception Day is about 2 weeks after the first day of your last menstrual day. This is the day the egg and sperm united, usually in the fallopian tube, and is now a single cell called a zygote. This tiny new cell, smaller than a grain of salt, contains all the genetic information for every detail of the newly created life -- the color of hair and eyes, the intricate fine lines of the fingerprint, the physical appearance, the gender, the height, and the skin tone. (It is a living cell


Days 2-5 This new life is now called an embryo, and his cells continuously divide while traveling down the fallopian tube before arriving in the uterus, around days 3-4. Meanwhile, the lining of the uterus prepares to receive this new life.


Three weeks gestation ~ the embryo (baby) begins to implant in the lining of the uterus on about day 6. Once this occurs, hormones trigger the mother's body to nurture the pregnancy and prevent her monthly periods. A blood test can show that the mother is pregnant. Around day 8, the baby is about the size of a "period" used in a sentence.


Four weeks gestation ~ The heart, about the size of a poppy seed, is the first organ to function. The first signs of brain development are evident, and the foundation for every organ system is already established and beginning to develop. 


(Your monthly period is due, but is either very light or late.... it's time to take a pregnancy test, which is available free through the Pregnancy Help Center.)


Six weeks gestation ~ The baby is growing rapidly and measures approximately 1/8 of an inch long. The basic structure for the entire central nervous system (brain and spinal cord) has formed. The eyes are developing, and the arm and leg buds are now visible. The beating heart can be seen on an ultrasound scan -- it's already beating about 100-120 times a minute!

(If you haven't already, make an appointment with the Pregnancy Help Center, and we'll show you the wonders of creation, and how your baby is developing!) 


Seven weeks gestation ~ The baby is now 1/3 of an inch long and is making its own blood. Depending on the baby's gender, the testicles or ovaries are beginning to form.


Eight Weeks gestation ~ The baby is now about 1/2 of an inch long. The elbows and fingers can be seen. Some reports show that the baby can move its trunk and limbs. Lungs begin to develop. Taste buds are forming on the tongue, tooth buds for "baby teeth" are taking shape in the jaw, and eyelids are beginning to form. The baby can respond to touch by reflex.


Nine weeks gestation ~ The baby measures 3/4 of an inch long and weight almost 1/8 of an ounce. The developing ears and nose are visible, and there is pigment in the retina. Nipples can now be seen on the chest. The limbs and fingers are growing rapidly, and the bones in the arms are beginning to calcify and harden.


(The Pregnancy Help Center can help you with tips on how to minimize that morning sickness you may be experiencing.)


Ten weeks gestation ~ the baby's brain is growing rapidly. Each minute it produces almost 250,000 new neurons! The upper and lower portions of the arms and legs are clearly seen, as well as the fingers and toes. By now the external ears are fully developed. A baby boy begins to produce the male hormone, testosterone.For the first time in development, the brain can make the muscles move on purpose.


11 weeks gestation ~ because the baby has all of the major organ systems and is a distinctly recognizable human being, he is no longer called an embryo, but is now known as a fetus, a Latin word for "young one". The baby is about 2 inches long and can yawn and suck. The eyelids are fully formed and closed to protect the developing eyes. The kidneys begin to produce urine. During the next several weeks, his body will grow rapidly, increasing in weight 30 times and tripling in length!


(There are lots of changes going on in your body, not to mention your life. Let the staff at the Pregnancy Help Center be your shoulder to cry on, and your sounding board when you need to figure something out.)


14 weeks gestation ~ now 3 1/2 inches long, the "young one" is coordinated enough to find his thumb and suck it. Fingernails and toenails are beginning to grow. The baby is also able to swallow and urinate.


16 weeks gestation ~ the heart beats between 110-180 times per minute and pumps about 26 gallons of blood each day. The gender of the baby might be seen on ultrasound. If she is a girl, millions of eggs are now forming in her ovaries. At almost 5 inches in length and weighing nearly 4 ounces, the baby can coordinate the movement of its arms and legs, though his mother will not likely feel it yet.


(The Pregnancy Help Center has materials available to help you learn more about the development of your baby. Make your appointment, and plan on visiting us weekly to earn free items for yourself and your baby.)

This information is intended for general educational purposes only and should not be relied upon as a substitute for professional medical advice.