Embryo 5 weeks old

You and your baby at 5 weeks pregnant

Your baby at 5 weeks

Your baby's nervous system is already developing, and the foundations for its major organs are in place. At this stage, the embryo is around 2mm long.

The heart is forming as a simple tube-like structure. Your baby already has some of its own blood vessels and blood begins to circulate.

A string of these blood vessels connects you to your baby and will become the umbilical cord.

At the same time, the embryo's outer layer of cells develops a groove and folds to form a hollow tube called the neural tube. This will become your baby's brain and spinal cord.

Defects in one end (the "tail end") of the neural tube lead to spina bifida. Defects in the "head end" lead to anencephaly, when the bones of the skull do not form properly.

Folic acid prevents spina bifida. You should start taking it as soon as you find out you're pregnant (even before you get pregnant, if possible).

You at 5 weeks

This is the time of the first missed period, when most women are only just beginning to think they may be pregnant. 

Find out what to expect on your NHS pregnancy journey.

Antenatal care (also called pregnancy or maternity care) is the care you get from midwives and doctors during your pregnancy to make sure you and your baby are as well as possible.

Contact your GP surgery or your preferred maternity service promptly once you know you're pregnant, so you start getting care at the right time. They'll arrange your first midwife appointment.

Starting your maternity care early in pregnancy is important if you have a health condition that may affect your pregnancy, such as heart or lung conditions, epilepsy, mental health problems, diabetes or asthma.

Your doctor or midwife will be able to advise you if you're taking medicines for your condition while you're pregnant, and provide the specialist care you and your baby need.

Do not stop taking any prescribed medicine without checking with your doctor or midwife first.

Things to think about

• You're advised to take 400 micrograms of folic acid a day while you're trying to get pregnant and until the 12th week of pregnancy.
• Stopping smoking is one of the best things you can do for your baby's health. Sign up for 28 days of free quitting advice and tips to your inbox.
• Avoid some foods in pregnancy to protect against infections.
• You can save a to-do list to keep track of things to do, such as taking folic acid and getting free dental care.
• Talk to your midwife, doctor or pharmacist before taking any medicines, or any herbal or homeopathic remedies.

Start4Life has more about you and your baby at 5 weeks of pregnancy

You can sign up for Start4Life's weekly emails for expert advice, videos and tips on pregnancy, birth and beyond.

Video: Is the pregnancy test accurate?

In this video, a midwife explains when you can take a pregnancy test and how to do it properly.

Media last reviewed: 5 February 2020
Media review due: 5 February 2023

Page last reviewed: 12 October 2021
Next review due: 12 October 2024

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5-8 weeks of pregnancy

The fifth week for a baby

The fifth week of embryo development is significant for the separation of the body of the unborn child and extra-embryonic auxiliary structures - the yolk sac, amniotic bladder, chorion. The process of active formation of organs and tissues continues. At this time, the birth of all the main systems of the future organism is taking place.

At the fifth week, the size of the embryo is 1.2-1.5 mm. It is possible to see the anterior pole - the place of the future head, as well as the posterior pole - the place of the future legs. The formation of the body occurs according to the law of symmetry - a chord is laid along, which is the axis of symmetry. It is around it that the laying of future symmetrical internal organs takes place. In the future, some of them will be formed by merging the rudiments (liver, heart), and some will remain double (lungs, kidneys, etc.).

The fetus in this period is in a curved state and looks like the letter C. By the end of the fifth week, the heart begins to pulsate, which has already formed. From the middle germ layer (mesoderm) begins the formation of the pancreas, liver, lungs, thyroid gland, trachea and larynx.

On the fifth allotment, the formation of the central nervous system also begins. The cells, which were previously located flat, begin to roll up, i.e., the formation of the neural tube occurs. The viability of the fetus is largely dependent on the complete closure of the tube, so the fifth week is of great importance. Folic acid is able to contribute to the high-quality closure of the tube. Therefore, when planning a pregnancy, specialists recommend taking drugs containing this substance. Also, folic acid is needed throughout the first trimester, but its role is especially important during 5-7 weeks. Along the tube there are bulges from which the formation of the brain sections will occur.

The processes located along the neural tube are called somites and represent future muscles.

Also, the fifth week is characterized by the beginning of the formation of germ cells in the embryo - this is another important moment in his life. In future people, at the stage of early development, the rudiments of eggs and spermatozoa are already laid.

Expectant mother at the fifth week

The period of five weeks is quite early, so if changes occur in the female body, they are insignificant. At this time, the cycle delay is one week, which not every woman pays attention to. If she is aware of her situation, thoughtfulness, peace, or, conversely, high activity may appear.

Odor intolerance and nausea are likely from the fifth week. Most women are prone to early toxicosis, which manifests itself in the form of vomiting, which usually occurs in the morning. Toxicosis can be both mild and severe. The second is accompanied by incessant vomiting. Women who are faced with a severe form of toxicosis are subject to hospitalization.

A feeling of heaviness in the chest or slight pain when pressed is also a sign of early pregnancy.

Sixth week for baby

During the sixth week, the embryo grows from approximately 3 mm to 6-7 mm. At this time, the shape of the embryo is cylindrical and resembles to a certain extent the embryo of a fish. The rudiments of arms and legs appear along the body, which in the sixth week have the form of processes. The arms are formed faster than the lower extremities; by the end of the sixth week, the rudiments of the hands are formed. The legs are not yet formed at the moment and remain in the rudimentary stage. At this time, the tube must completely close, and the rudiments of the hemispheres are formed from the brain bubbles.

The heart at this stage is characterized by intensive development and active pulsation. Inside this organ, division into chambers and compartments occurs, ventricles and atria appear. If you use highly sensitive ultrasound equipment, the heartbeat of the fetus can already be caught. 100-160 beats per minute at this stage makes the heart.

Also on the sixth week, the digestive tube is formed, which ends with the formation of the large and small intestines, stomach.

The sex glands continue to develop, the ureters are formed. An important process at this stage is the formation of chorionic villi, i.e., the laying of the future placenta. The sixth week is marked by the active stage of vascular growth and the "training" of the placenta. Of course, as a separate organ, the placenta has not yet formed and does not fulfill its functions, but the first trial steps are already being taken - there is an exchange of blood between the mother and the embryo, such an exchange is the precursor of future blood circulation.

The sixth week for the expectant mother

If the cycle is delayed by two weeks, which corresponds to the sixth obstetric week, the manifestations of toxicosis may increase in a woman. Nausea often leads to vomiting. If this happens more than two or three times a day, you should contact a specialist. In the chest, vascular permeability changes due to changes in the hormonal background. Therefore, a periodic sensation of tingling may join the feeling of fullness of the glands.

A woman in the sixth week is often accompanied by irritability, drowsiness, fatigue and weakness. All of these symptoms are the result of the influence of the hormonal background, which tries to create the best conditions for the development of the child. Experts note that the severity of the course of toxicosis directly depends on the emotional state of the woman. Therefore, the expectant mother should limit physical activity, avoid stressful situations, provide positive emotions and good mood.

Women may develop new taste preferences. Undoubtedly, it is necessary to ensure the comfort of the expectant mother, but one should not forget about common sense when choosing a diet. Even if it attracts to harmful products, they should not be consumed, of course, smoking and alcohol are contraindicated. It is undesirable to use smoked meats and any products containing chemical elements. The more correct the diet, the more benefits it can bring to the unborn baby.

Special attention should be paid to the water balance. Dehydration can only aggravate toxicosis, so it is important to monitor the amount of fluid consumed. Sometimes fruits, water and juices even become the only possible food for a woman.

Seventh week for a baby

At this age, the embryo reaches a length of 8-11 mm, its weight at the seventh week is less than a gram. The head is equal in size to half the body, while the shape of the body is arched. You can see in the lower part of the pelvic end a continuation of the coccyx, which outwardly resembles a tail.

On the seventh week, the formation of the embryo occurs quite intensively. On the hands, you can already see the interdigital spaces, but there is no division into individual fingers yet. The embryo begins to develop a face, on which a nasal fossa appears. In this place, a nose is formed a little later. Also in the seventh week, the initial development of the auricles occurs. They begin to form from two elevations on the head, both jaws are formed.

The seventh week is characterized by such an important event as the formation of the circulatory system of the female body and the fetus, as well as the umbilical cord. There is uteroplacental blood flow. From now on, tissue respiration and nutrition of the fetus occur through maternal blood. The unborn child falls under the protection of the mother's body. The future placenta (chorion) not only nourishes the embryo, but also acts as a protective filter, preventing harmful microorganisms and toxins that can significantly harm the fetus.

The seventh week for the future mother

From the seventh week, the growth of the uterus begins in a woman, this can be determined by a specialist during a gynecological examination. At this stage, many expectant mothers have an increase in the abdomen, which is one of the main signs of pregnancy. The growth of the uterus and the size of the embryo cannot cause an increase in the abdomen. This is due to the action of progesterone, which leads to lethargy of the intestinal loops, as well as a decrease in the tone of the anterior abdominal wall. Bloating occurs, which is the cause of visible changes in the abdomen.

Increased urination is a consequence of the fact that the total volume of blood in the female body increases. Such a change will accompany the expectant mother throughout the pregnancy and will especially manifest itself in the last trimester. If pain occurs during urination, then there is a reason for a visit to the doctor, since this is not considered the norm. Changes in bowel function are possible, constipation and diarrhea can occur with equal probability. The reasons may be a change in the usual diet or hormonal levels. Since regular daily stools ensure the timely removal of toxins from the body of the expectant mother, it must be carefully monitored. If you have problems with bowel movements, you should consult a specialist.

Eighth week for baby

The embryo is 15-20 mm long by the beginning of the eighth week and 40 mm by the end of it. The mass of the embryo is five grams. After the eighth week, the embryonic period ends and the fetal period begins. After eight weeks, experts no longer use the term embryo, the unborn child is called the fetus until it is born. The main features of the eighth week are the intensive development and modification of the embryo. There is a straightening of the body, and it is increasingly divided into segments - limbs, head and torso.

At this stage, the nervous system is actively developing. Also on the eighth week, the brain is divided into sections, the hemispheres are more clearly outlined, convolutions are formed.

The face of the unborn child becomes more prominent, ears, nostrils, eyes are formed. By the end of the eighth week, the upper lip is fully connected, and the face looks quite distinctly formed.

The process of ossification of the skull, arms and legs belongs to the features of this period. Bones harden. The formation of the fingers occurs, and the large one becomes isolated and opposed to the palm. Large joints (elbows and knees) are formed.

Brain structures, which are responsible for muscle tone, and the muscular system itself are also being actively formed. This allows the embryo to perform a variety of movements. The development of the digestive tract is almost completed by the end of this week. The intestines and stomach are supplied with nerve endings, which in the future will be able to provide motor functions of the gastrointestinal tract, the cavities of the kidneys, heart, bladder and ureters are formed.

The vascular system develops in the future placenta. The chorionic villi penetrate deeply into the wall of the uterus. Utero-placental circulation becomes full. The complex supply of the growing fetus is provided by the vessels of the umbilical cord, through which it receives blood enriched with oxygen and a variety of nutrients. Also, through these vessels, metabolic products and carbon dioxide are removed.

The eighth week for the expectant mother

The eighth week does not bring significant changes to the woman's body. All manifestations of toxicosis do not change their character, but are already much easier to bear. This is due to the fact that by this time pregnant women get used to their condition and find factors that facilitate it and create comfort. These can be certain foods, good sleep, one or another diet, walks, etc.

In this material, the gestational age is indicated as obstetric, that is, it is calculated from the first day of the preceding pregnancy menstruation.

Weekly development of the child | Regional Perinatal Center

Expectant mothers are always curious about how the fetus develops at a time when it is awaited with such impatience. Let's talk and look at the photos and pictures of how the fetus grows and develops week by week.

What does the puffer do for 9 whole months in mom's tummy? What does he feel, see and hear?

Let's start the story about the development of the fetus by weeks from the very beginning - from the moment of fertilization. A fetus up to 8 weeks old is called embryo , this occurs before the formation of all organ systems.

Embryo development: 1st week

The egg is fertilized and begins to actively split. The ovum travels to the uterus, freeing itself from the membrane along the way.

On the 6th-8th days, implantation of eggs is carried out - introduction into the uterus. The egg settles on the surface of the uterine mucosa and, using the chorionic villi, attaches to the uterine mucosa.

Embryo development: 2-3 weeks

Picture of embryo development at 3 weeks.

The embryo is actively developing, starting to separate from the membranes. At this stage, the beginnings of the muscular, skeletal and nervous systems are formed. Therefore, this period of pregnancy is considered important.

Embryo development: 4-7 weeks

Fetal development by week in pictures: week 4

Fetal development by week photo: week 4

Photo of an embryo before the 6th week of pregnancy.

The heart, head, arms, legs and tail are formed in the embryo :) . Gill slit is defined. The length of the embryo at the fifth week reaches 6 mm.

Fetal development by week photo: week 5

At the 7th week, the rudiments of the eyes, stomach and chest are determined, and fingers appear on the handles. The baby already has a sense organ - the vestibular apparatus. The length of the embryo is up to 12 mm.

Fetal development: 8th week

Fetal development by week photo: week 7-8

The face of the fetus can be identified, the mouth, nose, and auricles can be distinguished. The head of the embryo is large and its length corresponds to the length of the body; the fetal body is formed. All significant, but not yet fully formed, elements of the baby's body already exist. The nervous system, muscles, skeleton continue to improve.

Fetal development in the photo already sensitive arms and legs: week 8

The fetus developed skin sensitivity in the mouth area (preparation for the sucking reflex), and later in the face and palms.

At this stage of pregnancy, the genitals are already visible. Gill slits die. The fruit reaches 20 mm in length.

Fetal development: 9–10 weeks

Fetal development by week photo: week 9

Fingers and toes already with nails. The fetus begins to move in the pregnant woman's stomach, but the mother does not feel it yet. With a special stethoscope, you can hear the baby's heartbeat. Muscles continue to develop.

Fetal development by weeks photo: week 10

The entire surface of the fetal body is sensitive and the baby develops tactile sensations with pleasure, touching his own body, the walls of the amniotic sac and the umbilical cord. It is very curious to observe this on ultrasound. By the way, the baby first moves away from the ultrasound sensor (of course, because it is cold and unusual!), And then puts his hands and heels trying to touch the sensor.

It's amazing when a mother puts her hand to her stomach, the baby tries to master the world and tries to touch with his pen "from the back".

Development of the fetus: 11–14 weeks

The development of the fetus in the photo of the legs: Week 11