Pregnancy Week by Week
When you're pregnant, your body undergoes amazing changes as it grows a new life. You'll notice a change in your body and pregnancy symptoms week by week right until you reach your pregnancy due date. The changes to your body and the way you feel will be obvious to you and you'll notice the change in your abdomen size as your baby grows, but you won't know exactly how your baby looks unless you get regular ultrasounds.
A pregnancy ultrasound week by week isn't a realistic option for most women, but your doctor can show you images collected from numerous women and published in medical journals that show your growing fetus during each week of development. You can find pregnancy week by week pictures with just a basic Internet search or by purchasing or borrowing pregnancy books. There is an excellent book written by board-certified doctor Glade B. Curtis and Judith Schuler appropriately called Your Pregnancy, Week by Week that provides answers to most, if not all, of your pregnancy questions while explaining the weekly changes to you and your baby.
The First Trimester
Between weeks four and six, the time the average woman discovers she's pregnant; your baby is just in the embryo stage. Your developing baby doesn't look like a baby yet, but cells have clustered in places where your baby's heart and circulatory system will grow as well as where lungs, urinary tract, intestines, brain and entire nervous system will grow. There will be a double-layered fluid-filled bag (amniotic sac), a basic placenta and the beginnings of an umbilical cord. By 12 weeks, the end of the first trimester in the pregnancy calendar, your baby is essentially fully formed with all organs including miniscule vocal cords. Your baby has a long way to go yet before being able to live outside your body. But if you were to get an ultrasound right now, you'd be able to tell your baby was a tiny human. Your baby will also start to grow fuzzy hair like a peach around the end of the first trimester.
The Second Trimester
There are many changes in your pregnancy week by week in the second trimester. By the end of the 20th week your baby will be perfectly formed with ears that can hear your voice and noises around you. Your baby is roughly half the length she'll be at birth and has full fingers, toes and facial features. She'll be started her own routine daily and you'll notice there's times when she'll be more alert or quieter. She's growing hair and developing the hairline she'll have for the rest of her life.
Up until 28 weeks she'll be her most active. When looking at pregnancy week by week in the second trimester, studies indicate that by 21 to 22 weeks your baby will already have a favorite sleeping position. Babies born at 24 weeks have about a 40 percent chance of survival. By 26 weeks of the pregnancy calendar, the rate jumps to 80 percent with intensive care. At 28 weeks, eyes that have been fused shut until now open. Eyebrows, eyelashes and fingernails are complete.
The Third Trimester
At 29 weeks your baby can make facial expressions. He is skinny and wrinkly because there aren't enough fat deposits, but he has an excellent chance of survival if her were to be born now. At week 30 his bone marrow will have taken over red blood cell production and his first bowel movement is being developed in his intestines. At 32 weeks your baby will likely be able to breathe unaided if born now because his lungs have produced surfactant, the substance that helps them expand and prevents them from sticking together.
By 35 weeks your baby has grown approximately 1,000 times his original size. He'll have fully developed kidneys. The 37th week is officially classified as full term and he has fully developed lungs and enough fat to help him regulate his body temperature. It won't be long now before you enter the world of parenthood.
Desperation might sink in if according your pregnancy calculator week 40 has come and gone. But this is common and few babies are born right on their due dates. Your baby will continue to gain fat and grow until she's ready to be born. If size is a concern or there are other concerns, you can always talk to your health care practitioner about induction.