Friday, May 13, 2022

When Does A Fetus Develop Brain Activity

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What Develops In The Third Trimester

The third trimester is full of rapid growth. In fact, as your baby continues to grow, so does the brain. All the convoluted surfaces of the brain materialize, and the halves will separate, explains Gaither.

The most notable part of the brain during this final trimester is the cerebellum hence, the kicking, punching, wiggling, stretching, and all of the other movements your baby is performing.

While it may feel like you have control over nothing for the next 9 months, you do have a say in the foods you eat. Healthy brain development starts before pregnancy.

According to the Centers for Disease Control and Prevention , a healthy diet that includes folic acid, both from foods and dietary supplements, can promote a healthy nervous system.

There are a number of defects along the babys brain and spinal cord that can occur when there is an abnormality occurring within the first weeks of brain development, says Gaither. This may include or .

Gaither says two supplements in particular are involved with fetal brain development:

Developing The Tools To Study The Brain In Utero

Most of what scientists know about fetal brain development comes from looking at animal brains or analyzing human postmortem samples. This research has provided insights on the development of brain structure but offers few clues about how functional systems become organized.

The earliest investigations of human fetal brain function date back to the 1950s. When researchers placed electrodes on a pregnant womans abdomen and on the walls of her cervix during labor, they could detect electrical impulses that signaled fetal brain activity. Researchers began to notice that certain patterns of electrical activity were associated with neurological abnormalities.

In the 1990s, scientists began experimenting with fMRI to map the connections in different regions in the brain. fMRI detects changes in brain activity associated with changes in blood flow. During fMRI, the patient typically performs a tasklooking at pictures of faces or finger tapping, for instancewhile the machine scans his or her brain. Researchers look for areas of the brain that light up during the task.

Resting-state fMRI offered a more nuanced look at the highways and interstates connecting different brain regions. These connections form the basis of how different regions of the brain communicate with each other. Whereas investigators previously were limited to studying function within a particular brain region, they could now begin to ask big-picture, network-level questions about brain function.

In The First Three Years A Childs Brain Has Up To Twice As Many Synapses As It Will Have In Adulthood

Now that were a little more familiar with the fundamentals of the brain, lets take a look at brain development in children. Between conception and age three, a childs brain undergoes an impressive amount of change. At birth, it already has about all of the neurons it will ever have. It doubles in size in the first year, and by age three it has reached 80 percent of its adult volume.8-10

Even more importantly, synapses are formed at a faster rate during these years than at any other time. In fact, the brain creates many more of them than it needs: at age two or three, the brain has up to twice as many synapses as it will have in adulthood . These surplus connections are gradually eliminated throughout childhood and adolescence, a process sometimes referred to as blooming and pruning.11

Where To Get Help And Support

If your baby isnt meeting the milestones listed in their child health record, or if you think that something might be wrong with your babys , , communicating, behaviour, moving or growth, see your doctor or child and family health nurse. You can also call Pregnancy, Birth and Baby on 1800 882 436 to talk to a maternal child health nurse.

Vagueness Is A Virtue

Child Brain Development Infographic

As we’ve seen, there are difficulties with choosing a precise point when the unborn gets the right to live.

Although it’s uncomfortable to be so imprecise, the right answer may lie in accepting that there are degrees of right to life, and the foetus gets a stronger right to life as it develops.

This answer has the value of reflecting the way many people feel about things when they consider abortion: the more developed the foetus, the more unhappy they are about aborting it, and the more weight they give the rights of the foetus in comparison with the rights of the mother.

This view is sometimes called ‘gradualism’.

Do Fetuses Feel Pain What The Science Says

May 20, 2016 / 11:28 AM /

recently passed a law that requires doctors to give anesthesia to a fetus prior to performing an abortion that occurs at 20 weeks of gestation or later.

The law assumes that a fetus may be able to feel pain at that stage in development; however, doctors groups and other critics of the law argue that a fetus cannot feel pain at 20 weeks gestational age.

Indeed, the American College of Obstetricians and Gynecologists said it considers the case to be closed as to whether a fetus can feel pain at that stage in development.

“The science shows that based on gestational age, the fetus is not capable of feeling pain until the third trimester,” said Kate Connors, a spokesperson for ACOG. The third trimester begins at about 27 weeks of pregnancy.

To find out more, Live Science dug into the research and spoke with a leading expert on fetal pain. Here’s a look at what we found.

The problem with pain

One reason the question of fetal pain is so controversial is because pain is always a subjective experience, said Dr. Anne Davis, an OB/GYN and the consulting medical director for Physicians for Reproductive Health. Davis is an abortion provider.

Still, even though doctors can’t objectively measure pain, research has revealed much about how pain is experienced in the body and, more importantly, in the brain.

It’s in this sophisticated part of the brain that a person actually perceives the feeling of pain, Davis said.

Fetal development

Doctors react

How Your Baby’s Brain Develops

Once you find out you are pregnant, your baby’s brain is already in the works. In fact, just four weeks after conception, the neural plate forms, which is the foundation of your baby’s brain and spinal cord. As it grows longer, it folds in on itself until that fold changes into a groove. Eventually, that groove will turn into the neural tube. This neural tube, located along your baby’s back, is important to your baby’s brain and spinal cord development, which both develop from the neural tube.

How To Support Your Babys Brain Development

Its important to consume at least 600 mg of folate, or folic acid, during the first trimester and 400 mg later in pregnancy. This vitamin supports brain and spinal development, ensuring that the spinal tube fuses correctly and stimulating the growth of the brain throughout your pregnancy. Prenatal vitamins, created specifically to deliver the nutrients necessary during pregnancy, contain extra folate. If you arent getting enough from your diet, consult with your doctor about the best kind of prenatal vitamins for you. You can also get folate naturally from your food, specifically flax seed, whole grains, and leafy green vegetables.

Its important to consume at least 600 mg of folate, or folic acid, during the first trimester and 400 mg later in pregnancy. This vitamin supports brain and spinal development, ensuring that the spinal tube fuses correctly and stimulating the growth of the brain throughout your pregnancy.

Eating a balanced diet of whole foods and drinking plenty of water will help your baby’s brain develop properly. 

When Does A Fetus Have Brain Activity

The first synapses in babys spinal cord form during week 7 of pregnancy. By week 8, electrical activity begins in the brain allowing your baby to coordinate his first movements that doctors can even see on an ultrasound!  

Your babys brain continues to develop in the coming weeks, endowing him with a remarkable range of involuntary movements like stretching, yawning and sucking by the end of the first trimester and more coordinated movements in the second trimester. 

That said, the brainstem, which controls vital functions like heart rate and breathing, isnt mostly complete until the end of the second trimester, and the cerebral cortex doesnt take up its duties until the third trimester. 

In fact, the cerebral cortex which is responsible for voluntary actions, thinking and feeling only starts to work around the end of pregnancy, with simple electrical activity detectable in regions associated with senses and motor skills in premature babies. 

Baby Brain Development: Motor Skills

Your child is equipped for physical survival. Even before birth, their brains and nerves are developed to the point that they can control basic reflexes and vital functions like breathing, swallowing, and sleeping. As you may have noticed, physical reflexes begin to develop during early pregnancy, when your developing baby becomes capable of reacting to stimuli by moving his arms and kicking his legs. This is fairly apparent during your babys rapid physical and mental development in the sixth month of pregnancy.

In the seventh month, a process called myelination begins in which a dense, fat-based substance forms along the connections between neurons, allowing signals to pass between them with increasing speed. Among the first neurons to undergo myelination are those located in the brain regions responsible for motor developmentthe brainstem and spinal cordand theyll be the most fully developed by then.

Enfamama A+ Club is here for you and your developing baby. Get expert advice and more when you join the club. 

Development Of The Neural Circuits Of Consciousness

At birth, the newborn brain is in a transitional stage of development with an almost adult number of neurons but an immature set of connections . During the few months after birth, there is an overproduction of synapses accompanied by a process of synaptic elimination and stabilization, which lasts until adolescence . Myelination begins prenatally, but is not completed until the third decade in the frontal cortex where the highest executive functions and conscious thoughts take place .

Figure 2

Comparison between the maturation of thalamocortical-cortical connections and somatosensory evoked potentials . In the early preterm infant , thalamic axons establish a dense synaptic network in the subplate. After approximately 25 gestational weeks thalamic fibers make synapses in the deep cortical layers. In the full-term infants, the thalamic fibers have reached their final destination in layer IV of the cortex. This is reflected by the SEP responses. In the early preterms, the evoked responses consist only of long depolarizations of the deep layers. A delayed cortical activation can be seen. When the thalamic-cortical fibers extend to the cortex, faster cortical responses are seen, paralleling the accumulation of synapses in layer IV. Reprinted from Vanhatalo et al., Semin Fetal Neonatal Med 11:464-470, Copyright © 2006 Elsevier Ltd., with permission.

Fetal Brain Development Week 19

The brain becomes capable of forming millions of motor neurons, enabling the baby to develop and make muscle movements voluntarily. The forebrain further develop into left and right cerebral hemispheres of the brain. The nerve cells required for the processing of all the senses are also developing rapidly. This is the stage where your baby can hear you.

Fetal Brain Development Week 3

Boosting babies brain development

The egg is now a ball of cells called as the blastocyst. The eggs has a unique DNA that carriers the necessary information. Of the two strands, one comes from the father and the other from the mother. There are two types of cells, the inner cells which will later form the embryo and the outer cells which will form the membrane.

The Neurobiology Of The Fetus: Anatomical Pathways

Notwithstanding limitations, it is useful to view the pain system as an alarm system. Viewed in this way, a noxious stimulus is an event that activates free nerve endings in the skin, similar to pushing an alarm button. The electric cable from the button to the alarm is similar to the connection between the nerve endings and the brain. The brain is the alarm that rings out pain. Whether the fetus can respond to a noxious stimulus with pain can thus be decided in part by determining when the alarm system is completely developed.

Free nerve endings, the alarm buttons, begin to develop at about seven weeks’ gestation,; projections from the spinal cord, the major cable to the brain, can reach the thalamus at seven weeks’ gestation. An intact spinothalamic projection might be viewed as the minimal necessary anatomical architecture to support pain processing, putting the lower limit for the experience of pain at seven weeks’ gestation.

Can a fetus experience pain?

Spinothalamic projections into the subplate may provide the minimal necessary anatomy for pain experience, but this view does not account for the transient nature of the subplate and its apparent role in the maturation of functional cortical connections. A lack of functional neuronal activity within the subplate calls into question the pain experience of a fetus before the penetration of spinothalamic fibres into the cortical plate.

Nobody Can Say When An Individual Life Begins But The Facts Can Help Show When A Life Does Not Begin

Crucially, the co-ordinated brain activity required for consciousness does not occur until 24-25 weeks of pregnancy. File photograph: Paolo K/iStock


There are not two views on abortion in Ireland. There are 4,803,748 different perspectives. In the weeks leading up to polling day, the Irish people have started from the ground up and the debate is now firmly in the parameters of under what circumstances should abortion be available?

Scientists are generally a stroppy sort of people. We are trained to question absolutely everything, and we have a deep scepticism of authority or unjustified assertion. We make individual conclusions based on an objective assessment of the evidence and beyond the core accepted scientific facts we disagree with each other constantly.

Since last week, 1,500 Irish scientists ranging from PhD students to Irelands only Nobel Laureate for the sciences have signed a letter written by Scientists for Yes, summarising our views on abortion.

Each one of those 1,500 individual scientists has their own distinct moral values, whether religious or secular. Each of us assessed the social and scientific evidence surrounding the issue of abortion in society and each arrived at her or his own unique, personal stance, and how best to manage abortion in Ireland.

1. Brain development

2. Evolution and human uniqueness

3. Mental health

4. Disabilities

5. Conception

6. Organ development

From Conception To Age Three: An Outline Of Early Brain Development

First Trimester

The development of the brain begins in the first few weeks after conception. Most of the structural features of the brain appear during the embryonic period ; these structures then continue to grow and develop during the fetal period .19,20

The first key event of brain development is the formation of the neural tube. About two weeks after conception, the neural plate, a layer of specialized cells in the embryo, begins to slowly fold over onto itself, eventually forming a tube-shaped structure. The tube gradually closes as the edges of the plate fuse together; this process is usually complete by four weeks after conception. The neural tube continues to change, eventually becoming the brain and spinal cord.20,21

About seven weeks after conception the first neurons and synapses begin to develop in the spinal cord. These early neural connections allow the fetus to make its first movements, which can be detected by ultrasound and MRI even though in most cases the mother cannot feel them. These movements, in turn, provide the brain with sensory input that spurs on its development. More coordinated movements develop over the next several weeks.22

Second Trimester

Early in the second trimester, gyri and sulci begin to appear on the brains surface; by the end of this trimester, this process is almost complete. The cerebral cortex is growing in thickness and complexity and synapse formation in this area is beginning.20,21,23

Third Trimester
Year One
Year Two

What You Can Do To Support This Growth

editorial processMedical Review Board

If you just discovered that you’re pregnant, you will likely spend the next months ahead wondering how your baby is growing and developing. Questions like: “What color will my baby’s eyes be?” or “When can my baby hear me?” may run through your mind. You may even wonder about your baby’s brain development.

Fortunately, fetal brain development typically follows a pretty predictable schedule. In fact, the fetal nervous system, or your baby’s brain and spinal cord, is one of the first systems to develop. So, as you continue along with your prenatal care and get your , your baby also will be moving along and at a predictable rate.

An Overview Of Brain Anatomy

The easiest way to get to know the brain is to learn the main structures of the adult brain and how they relate to its function . It should be kept in mind that the relationship between brain structure and function is never simple. Although we often hear claims about the language area or emotion center of the brain, statements like these are simplifications; in reality, even the simplest mental activities involve multiple brain regions.

The brain can be divided into three major parts. The brain stem, shaped like a widening stalk, connects the spinal cord to the upper brain. It controls reflexes and involuntary processes like breathing and heart rate. Behind the brain stem and below the upper brain is the cerebellum, which is involved in balance and coordination.

The cerebrum, the largest part of the brain, sits above the brain stem and cerebellum. While each of the brains structures plays an essential role, the cerebrum is the area most involved in higher processes like memory and learning. The cerebrums outer surface is called the cerebral cortex. Although less than one-fourth of an inch thick , it is where the brains most advanced activities such as planning and decision-making take place.

We Dont Know Where Life Begins But Heres What We Do Know About What Develops When During A Pregnancy

In our Q&A: Eighth Amendment Referendum series, we are answering questions our readers have submitted in relation to the upcoming vote on 25 May.


A number of people have asked a version of these questions. Here are some of those queries: 

  •  I would just like more information to clarify how developed a foetus is at 10 weeks and at 12 weeks?
  • Can you show us an image of a 12-week old foetus so that we know what we are dealing with?
  • I would like to know what medical science has shown regarding at what stage an unborn baby is capable of feeling pain and suffering?
  • What is the consensus of when a life begins?


OVER THE PAST few weeks, the development of embryos and foetuses at various stages of a pregnancy have been used in campaigns urging people to vote either Yes or No in the Eighth Amendment referendum.

In particular, references to the development of the heart, brain and facial features during a pregnancy have been used as an emotive argument to retain the Eighth Amendment.

When does life begin?

There is little consensus of when life begins: the BBC has a good, simplified guide hereon the different stages of pregnancy where life could be interpreted as beginning: including when the foetus first moves, when the brain is fully developed, or when the foetus reaches viability .

But ultimately, as the guide states, theres no agreement in medicine, philosophy or theology as to what stage of foetal development should be associated with the right to life.

When Does A Fetus Develop A Brain

Pregnancy is an exciting time full of rapid change and development for both you and your baby. While the growth happening on the outside is clear to everyone , its the development we cant see that is truly fascinating.

Your fetus will begin the process of developing a brain around week 5, but it isnt until week 6 or 7 when the neural tube closes and the brain separates into three parts, that the real fun begins.

Fetal Brain Development Week 28 40

Why You Need to Read to Your Baby Right Now

The brain completely monitors the breathing and regulates the body temperature. This being the beginning of the third trimester, the brain continues to grow and increase rapidly in size, all the while establishing connections between the nerve cells. The brain along with the lung is the last organ to develop, and the process is completed, close to the end of the third trimester. A newborns brain is only about one-quarter the size of an adults.

Psychological Arguments For Fetal Pain

A different approach to unravelling whether a fetus feels pain is to focus more closely on what we mean by pain. Many people take the International Association for the Study of Pain definition as their starting point, which states that pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage pain is always subjective. Each individual learns the application of the word through experiences related to injury in early life. That definition is often interpreted as meaning that pain is not just phenomenological but also reflective. As others have pointed out, such a demanding definition of pain restricts pain almost exclusively to fairly mature human beings. To ease that restriction it might be worthwhile to consider a less sophisticated definition, which focuses less on subjective reflection and more on the immediate and unreflective feel of pain .

The Earliest Messages That The Brain Receives Have An Enormous Impact

Early brain development is the foundation of human adaptability and resilience, but these qualities come at a price. Because experiences have such a great potential to affect brain development, children are especially vulnerable to persistent negative influences during this period. On the other hand, these early years are a window of opportunity for parents, caregivers, and communities: positive early experiences have a huge effect on childrens chances for achievement, success, and happiness.

Fetal Brain Development Week 4

The blastocyst can now be called an embryo as it has now reached the uterus and buried itself in the wall. The uterus wall has become thick enough to support the baby. The embryo will now receive all the nourishment from the mother. In this phase, the embryo further develops the three brain sections; forebrain, middle brain and hind brain, along with the optical stalk.

What Can Harm Fetal Brain Development

One of the largest contributors to fetal harm is alcohol. Drinking while pregnant can severely impact the growth and development of the babys brain. Alcohol consumption can cause fetal alcohol syndrome, which causes brain damage and problems with a babys growth. Babies with fetal alcohol syndrome may have a certain cast to their facial features, including drooping eyes. They may also experience speech delays and mild to severe retardation. There is no known safe amount of alcohol to consume while pregnant, and the effects of fetal alcohol syndrome are irreversible. If you are having trouble abstaining from drinking, its important to discuss this with your doctor right away.

One of the largest contributors to fetal harm is alcohol. Drinking while pregnant can severely impact the growth and development of the babys brain.

Smoking is also harmful to a babys development overall, including low birth weight and a reduction of the formation of neurons in the brain. Cigarette smoke, and the chemicals it contains, also impact the communication between neurons.

If you dont have a cat, its best to wait until after you have the baby to get one. Feline feces can contain parasites that cause toxoplasmosis, which can be harmful to your baby and especially their brain. If you do have a cat, get someone else to clean the litter box and be sure to wear gloves if you do it yourself. 

Fetal Brain Development Week 5

The first sign of the cerebral hemisphere is visible at this stage. As the brain continues to develop, other organs like the circulatory system begins to function with all four chambers of the heart present. We can see upper and lower limb buds. The heart too starts to beat with twice the rate of the mother.

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