Fetal development stages month by month

MERRION ULTRASOUND
F E T A L D E V E L O P M E N T S T A G E S
M O N T H B Y M O N T H
MAY 2023
DUBLIN'S
CREATED BY JACKIE DE BURCA, CWA EUROPE
M E D I C A L L Y L E D
sonographer
facilitated
ultrasound clinic

Fetal Development Stages
Month By Month
WELCOME
Each month exciting new
developments are happening for
you and your baby.
This digital magazine highlights
what you should expect on a
month to month basis, keeping you
in tune with baby's development
each month.
DISCLAIMER
Please do not consider any of the
information provided here as a
substitute for medical advice. At all
times seek medical advice directly
with your own doctor and medical
team.
PHONE
637 4060
E-MAIL
info@merrionultrasound.ie
WEBSITE
merrionultrasound.ie

MONTH 1
During month 1, the fertilised egg is growing, cushioned by a watertight sac - the
amniotic sac - which is forming around it and gradually being filled with fluid. At
the same time the placenta is also developing. The purpose of this flat, round
organ is to transfer waste away from the baby and nutrients to the baby, from the
mother.
By the end of this month, baby is not even as big as a grain of rice, at around a
quarter of an inch in length. However baby's blood cells are developing and her
circulation is beginning. Also by the end of the month baby's small heart tube is
beating at around 65 times per minute. Her face is primitive, and right now her
eyes are just large dark circles.

MONTH 2
During this month baby's face is developing, and she has little folds of skin which
will turn into her ears. Right now she has small boats that will become her legs
and arms, and her eyes, toes and fingers are also developing.
The sensory organs and digestive tract are also starting to develop, and at the
same time bone is beginning to replace cartilage. Her neural tube is formed. The
proportion of her head is rather large in comparison to the rest of her body. By
around six weeks an ultrasound should be able to detect her heartbeat. After
eight weeks she will be referred to as a fetus as opposed to an embryo.

MONTH 3
At this stage there's been a lot of progress, and her feet, toes, hands, fingers and
arms I now fully formed. Even toenails are starting to develop. Her external ears
have now developed, and teeth are also forming. She can actually open and close
her mouth and her fists.
Although her reproductive organs are also developing, as yet it is still difficult to
tellx during an ultrasound scan. By the end of this month she's actually fully
formed, her liver is producing bile and all of her organs and extremities are
formed, but will continue to mature. Her urinary and circulatory systems are also
functioning. After this month, the risk of miscarriage has dropped considerably.
By the end of month three she should weigh around 1 ounce and measure
around 4 inches in length.

MONTH 4
At this stage your baby is able to yawn, stretch, suck her thumb and make faces.
At this stage, her genitalia and reproductive organs are fully formed, and it's
possible to tell during ultrasound scan that she's a girl. Also her but could be
audible using a Doppler.
Her hair, eyelashes, eyebrows, nails, eyelids, toes and fingers are now defined. Her
nervous system is also beginning to function. By the end of this month she
should weigh around 4 ounces and be approximately 6 inches in length.

MONTH 5
Lanugo, which is a sort, fine hair is now covering her back, shoulders and temples.
This is therefore protection and is normally shared within the first week of her life.
Her hair was also continuing to grow on her head.
At this stage her muscles are developing and so she was exercising them, which
is called quickening. This means that you may start to feel her move.
Her skin is covered by a kind of cheesy substance, which is called vernix caseosa,
and this is thought to protect the skin against the long duration of exposure to
amniotic fluid. This watershed before her birth.
By the end of this month her weight should be between half a pound to 1 pound,
and she should measure around 10 inches in length.

MONTH 6
This is the month that babies eyelids will begin to part and she will be able to
open her eyes. She also starts to respond to sounds. Her toe and fingerprints are
now visible and she may be hiccuping from time to time.
You can see the veins through translucent skin, which is wrinkled and reddish in
colour. If she were to be born prematurely, after a week 23, she may survive in
intensive care.
By the end of this month she should weigh around 2 pounds and be around 12
inches in length.

MONTH 7
Hearing is now fully developed, and she's changing her position quite frequently.
She's responding more and more to stimuli, which include light, sound and pain.
At this stage the amniotic fluid is diminishing, and she's continuing to mature
and also of developing body fat reserves.
After this month if she was born prematurely, she has a good chance of survival.
At the end of this month she should weigh between £2-£4 and be around 14
inches in length.

MONTH 8
At this stage her brain is developing quite rapidly, and she can both here and see.
Apart from her lungs, which still may be a little immature, most of her internal
systems are now well developed.
She is continuing to mature and also to develop her body fat reserves. This is the
month you are most likely to realise that she's clicking more and more.
At the end of this month she may as much as 5 pounds, and can be around 18
inches in length.

MONTH 9
During months 9, her reflexes are now coordinated, which means she could
grasp firmly, respond to light, touch and sounds as well as being able to blink.
Her wrongs are almost fully developed at this stage.
Now that space is more tight she is less likely to move around as much as in
month eight. She will be changing position however in preparation for Labour
and delivery, so she should be dropping down into a pelvic region.
At this stage she could weigh around 7 pounds and be between 18 to 20 inches
in length.

MERRION
ULTRASOUND
FETAL DEVELOPMENT
STAGES MONTH BY
MONTH