Pregnancy and baby development
Week one to four: ovulation and conception occur. The gender of your baby is already
determined upon fertilization and the development of the brain, spinal cord, heart, and
gastrointestinal tract begin.
Week five: the heart is now beating at a steady rhythm, but is still about twice as fast as
yours.
Week six: the baby’s lungs, jaw, nose, and palate begin to form.
Week seven: the baby is now in it’s seventh week of development and every essential organ
has now begun to form as well as the eyelids and tongue.
Week eight: The bones are beginning to form, and the muscles can contract. The facial
features continue to mature, and the eyelids are now more developed. And the baby now has
knees!
Week nine: Most of the baby’s joints are formed so the baby can move around, although it is
still too small to feel. The baby can now make a fist or grab onto an object placed in its hand.
And the unique fingerprints of your baby are evident on their skin.
Week ten: The baby’s eyelids are fused shut while the irises form. The eye colour is also
determined at this point.
Week eleven: Nearly all structures and organs are formed and beginning to function. The
baby now has fingers and toes; also the fingernails and hair are beginning to grow. The baby
is just two and a half months yet already the genitalia have clearly formed into male or
female, though it cannot be seen on an ultrasound quite yet.
Week twelve: the baby is just over two inches, and yet the vocal chords are beginning to
form. Also the ears and eyes shift to their normal place during this stage.
Up till this point you can have an abortion on demand in hospitals in Greece.
Week thirteen: The baby now begins to practice inhaling and exhaling movements. Their
hands are now functional and you should be able to hear your baby’s heartbeat through a
Doppler.
Week fourteen: The baby’s thyroid will now start producing hormones that will continue
through its entire life. Further development of the baby’s reproductive organs will occur.
Week fifteen: Some of the baby’s movements can be felt; they can also grasp, squint, frown,
grimace and maybe suck their thumb. Also eyebrows are beginning to grow and even the hair
on their head is sprouting.
Week sixteen: At this point you may be able to find out if the baby is a boy or girl with a
sonographer. And if you could see inside, you would notice that they can suck, swallow, blink
and might even hiccup. They can finally breathe now, starting to exercise their lungs for life
outside the womb.
Week seventeen: The baby is now about 13cm (5.12 inches) long, and it now “looks” like a
baby. Also the baby’s skeleton is in the process of transforming from cartilage to bone.
Week eighteen: The vocal chords are now fully developed and can go through the motions of
crying but cannot make noise without air. The baby’s heart, including ventricles and
chambers, should be visible during an ultrasound.
Week nineteen: Your baby has the same awake and sleep patterns of a newborn. It has a
favourite position for sleep and recognizable active and rest periods. Scalp hair becomes
much more apparent this week and permanent teeth form behind the milk teeth.
Up to this point you can abort the baby if it is a case of rape or incest.
Week twenty: The rapid growth stage is about over. While things have slowed down, this
next stage is vital to survival. At this point Immunities are being transferred from you to your
baby. These immune cells will protect the baby from viruses you've already had for up to six
months after birth. The nerve cells for taste, smell, hearing, seeing, and touch are now
developing so your baby may begin to startle at loud noises. The baby can now amazingly
hear noises from outside the womb, and becomes familiar with voices, music and various
noises.
Week twenty-one: the baby now measures about 10.51 inches (26.7cm) in length, and is now
producing white blood cells. The skin has changed from translucent to more opaque. Sleeping
patterns become more consistent, and the baby’s tongue is fully formed.
At this point it is still legal in Greece to abort the child if there is fetal abnormalities.
Week twenty-two: Your baby now weighs close to a pound! Their eyelids and eyebrows are
fully formed and the baby’s brain has hit a stage of rapid growth.
Week twenty-three: The proportions of the baby are now quite similar to that of a newborn.
If born now, your baby has a fifteen percent chance of survival, and its odds going up with
each passing day.
Week twenty-four: During this week the baby gains about six ounces of weight in muscle,
bone mass and organs. The baby’s taste buds begin to form and its muscle coordination
increases, as the baby is now able to suck its thumb.
Week twenty-five: The structures in the spine begin to form as well as the blood vessels in
the lungs. The baby’s nostrils open and the nerves around the mouth and lip area show more
sensitivity.
Week twenty- six: To support the baby’s increasing growth the spine must become stronger
and more supple. The air sacs in the lungs now form and your baby’s eyes finally begin to
open and blink. Their retinas begin to form and brain activity for hearing and sight becomes
detectable.
Week twenty-seven: Your baby’s brain continues growing rapidly, so talking and reading to
your child at this stage is great! The baby’s response to sounds grows increasingly and its
retinas are now fully formed. You can also expect it to grow about an inch over this week!
Week twenty-eight: The baby is filling out with muscle tissue and bone; and hair on its head,
eyebrows and eyelashes become more obvious. Also the baby’s eyes are fully formed by this
stage.
Week twenty-nine: The baby’s head is now in proportion to its body, as well as fat
accumulating under its skin. The brain can now control certain functions such as breathing
and body temperatures, and the baby’s eyes can now move in its sockets. It is also becoming
increasingly sensitive to light, sound, taste and smell.
Week thirty: The baby will spend more and more time practicing opening and closing
eyelids, and is also now capable of producing tears. The baby’s bone marrow is now in charge
of producing red blood cells to transport oxygen and remove waste.
Week thirty-one: At this stage the baby’s brain enters another stage of rapid growth and may
already start to prefer certain music types to others. The bones will continue to harden as well
as fat accumulating under the skin. Lungs are now the only organ left to complete
development.
Week thirty-two: At this stage the baby tends not to move around as much due to limited
space inside the womb, but still has a good amount of growth left in these last few weeks. All
five senses are working in the little one as well as the ability to have REM sleep.
Week thirty-three: The connections in the baby’s brain are forming in great numbers; this
will provide the skills needed as a newborn. As the majority of bones are now hardening, the
baby’s skull is soft and not completely joined this will make childbirth slightly easier.
Week thirty-four: The baby can blink and even focus on a light that is shined on the womb.
Antibodies from your blood are being transferred to your baby to help protect from disease;
breast milk will help with this after birth as well. The baby may already be turned to a head
down position to prepare for birth.
Week thirty-five: Most babies born at this stage will survive without many long-term issues.
The baby’s hear should be fully developed as well as the continuation of fat accumulation
under the skin. The fat will help regulate the baby’s body temperature.
Week thirty-six: The baby will continue to develop its lungs and will drop into the birth
canal if it hasn’t already. Also the kidneys should now be fully developed and already
processing waste.
Week thirty-seven: The baby is now officially full term. Its will continue to practice
breathing and looking towards the light penetrating the uterus lining, which is getting thin
now.
Week thirty-eight to birth: The baby will continue gaining fat and practicing breathing. The
lungs will also continue to mature. Soon the little one will be introduced into the world!
Sources:
http://www.pregnancy.org/fetaldevelopment/week-five
http://www.americanpregnancy.org/duringpregnancy/fetaldevelopment1.htm
http://www.babycenter.com/fetal-development-images-4-weeks