
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Pregnancy: week 5
Medical expert of the article
Last reviewed: 06.07.2025
The 5th week of pregnancy is characterized by one important event in the life of the embryo: it begins to separate from the extraembryonic. During this period, the embryo can already determine where the head will be, where the legs will be. At this time, important functional systems of the future person are gradually formed.
In the center of the embryo, the heart, larynx, and trachea are formed. It is quite difficult to imagine, but the embryo, whose length is only 2 mm, already begins to beat. At this stage of development, it is impossible to hear the heartbeat, even with the help of special research methods, this can only be done from the seventh week of pregnancy. Over time, blood vessels and the beginnings of the digestive system (pancreas, liver) begin to appear. At this stage, the embryo resembles the letter "C". Along the neural tube, areas of tissue develop that will become muscle and other tissues in the future.
This week, the neural tube partially closes (in the middle sections). The neural tube is a kind of prototype of the central nervous system, so timely closure of the tube is of great importance. Subsequently, the spinal cord will form from this tube. This is how the nervous system is laid down - the basis of human motor and mental functions. Folic acid plays a major role in this, the deficiency of which in the body can cause severe developmental defects.
The 5th obstetric week of pregnancy is the third week of intrauterine development of the embryo. As a rule, the news of pregnancy falls precisely at this period. The joy that a woman experiences is also useful for the future child, since there is already a strong connection between the mother and child and the best conditions for development are created by the favorable emotional mood of the woman.
The 5th week of pregnancy is characterized by an intensified process of hormonal changes in the woman's body. The corpus luteum of the ovary produces the most important hormones necessary for the normal development of the fetus - progesterone and estrogen. The membrane in which the fetus is located produces a hormone characteristic only of pregnant women - human chorionic gonadotropin, which is abbreviated as hCG. It is on the presence of this hormone in the blood or urine that all tests are based that help determine pregnancy at an early stage.
If a woman has had ectopic pregnancy in the past (or the doctor suspects this pathology), it is recommended to undergo an ultrasound and do a blood test for hCG levels. The 5th week of pregnancy is the period when you can make sure that the fetus is developing normally or identify any possible pathologies. If the pregnancy proceeds without pathologies, the hCG level in the woman's body becomes higher every day.
[ 1 ]
Ultrasound at 5 weeks of pregnancy
In the fifth week of pregnancy, the gynecologist is not able to say for sure whether the woman is pregnant or not. During this period, if a woman is suspected of being pregnant, she undergoes her first ultrasound examination, during which it is possible to determine the size of the uterus, whether it is a multiple pregnancy or not, and the location of the embryo in the uterus. The 5th week of pregnancy is the time when the heart of the future little person begins to beat. A good specialist during an ultrasound examination (provided that there is modern equipment) will be able to predict and evaluate the development of the fetus by comparing motor activity with heart rhythms.
How does the child grow?
At this stage, the embryo is growing at a breakneck pace and now looks more like a tiny tadpole than a human being. It now consists of three layers - the ectoderm, mesoderm, and endoderm - which will later form all of its organs and tissues.
The medullary tube, which will later form the baby's brain, spinal cord, nerves, and spine, begins to develop in the top layer, called the ectoderm. This layer also provides the baby with skin, hair, nails, breast and sweat glands, and tooth enamel.
His heart and circulatory system begin to form in the middle layer, the mesoderm. The mesoderm will also form the baby's muscles, cartilage, bones, and subcutaneous tissue.
The third layer, or endoderm, is responsible for the formation of the lungs, intestines, and rudimentary urinary system, thyroid gland, liver, and pancreas. Meanwhile, the primitive placenta and umbilical cord, which transmit nutrients and oxygen to the baby, are already functioning.
Important: Each baby's development is unique. Our information is designed to give you a general idea of fetal development.
Fruit size
In the 5th week of pregnancy, the formation of some internal organs and systems of the baby begins. It is at this stage that the expectant mother should include in her diet foods containing folic acid (or take it in tablet form) and worry, fret, worry, etc. less, since it is in this week that the central nervous system, spinal cord, brain, blood vessels, etc. begin to develop. The amniotic fluid in which the embryo is located carries out the exchange of useful (and not only) substances between the fetus and the mother's body. During this period, the dependence of the small organism on the emotional mood, nutrition and lifestyle of its expectant mother appears. The 5th week of pregnancy is a fairly short period, and the embryo at this stage of development is very small - only 2-3 mm, its weight is no more than 3 grams. However, it is already beginning to form a respiratory system, digestive organs. You can also see the rudiments of future eyes, ears, mouth, nose, legs and arms, fingers.
Diseases in the 5th week of pregnancy
The feelings of a woman who is in the fifth week of pregnancy can be very different and contradictory. She can experience sudden mood swings, during this period the woman notes that she has become more tired, feels exhausted, she constantly wants to sleep, taste preferences change. Headaches, dizziness appear, all these conditions are associated with the active activity of hormones in the body. The 5th week of pregnancy can be the beginning of unpleasant sensations associated with the first manifestations of toxicosis. A woman can feel both mild nausea and severe nausea, vomiting often appears in the morning, a feeling of nausea can also be provoked by a certain smell (food, deodorants, etc.), the sight or taste of food. A woman can completely lose her appetite, she begins to smell more acutely.
At this time, the woman begins to have frequent urges to urinate, as the enlarged uterus begins to put pressure on the bladder.
In some cases, a woman may feel that she has caught a cold, since a slight increase in body temperature is quite natural in this position and signs of illness are felt (weakness, headaches, etc.).
Temperature 37
A low body temperature (around 37 degrees) during pregnancy, particularly in the early stages, is quite normal, so there is no need to worry too much about it. This condition, which may accompany the 5th week of pregnancy, is caused by hormonal changes in the body. If the temperature in the early stages is not higher than 37.5 degrees and there are no other unpleasant symptoms, then there is no reason to worry. Doctors explain the increase in temperature by the increased amount of progesterone in the body. In addition, the temperature can rise from excessive exposure to the sun, lack of fresh air in the room, etc.
Cold
With the onset of pregnancy, the body's defenses are significantly weakened, which can lead to a cold. The 5th week of pregnancy is a very important stage in the formation of the embryo, so it is extremely undesirable to suffer from colds at this time. In the first three months of pregnancy, taking any medications is prohibited, at the same time, a severe course of the disease can lead to developmental defects in the child.
At the first signs of a cold, especially in the early stages, a pregnant woman needs to drink plenty of warm drinks (tea with raspberries, honey, herbal infusions), gargle with soda and herbal solutions, and rinse the nose with special products containing sea water. However, one should not abuse folk remedies, since many herbs have an abortive effect and can cause a miscarriage.
Toxicosis
The 5th week of pregnancy may begin with the manifestation of toxicosis. During this period, a woman may begin to feel sick from previously favorite dishes and various smells. A pregnant woman changes completely - from the internal structure to external qualities. About 85% of women in position at the beginning of pregnancy experience disgust for food. Hormones are to blame. Some women cannot stand the sight and smell of fairly harmful products in their current condition (fried, seafood, fast food, etc.). But sometimes the female body begins to reject most of the products, among which are those necessary for the proper development of the baby.
Most women cannot tolerate protein foods (poultry, beef, eggs, etc.). But these products can be replaced with other products with a high protein content - nuts, legumes. In some cases, women react more to the smell, so you can eat dishes with a small content of protein products (vegetable stew with small pieces of meat).
Milk is also a product that most pregnant women cannot tolerate normally. But milk is the main source of calcium, which is so important for both mother and child. If the body protests against dairy products, you can replace them with freshly squeezed juices, white cabbage.
Usually, toxicosis goes away on its own at the end of the first trimester. The woman's health improves, morning sickness goes away, and the usual taste returns.
Nausea
Nausea is a common complaint among women in early pregnancy. It occurs in more than half of pregnant women, and a slight feeling of nausea at the very beginning of pregnancy is familiar to almost all women.
The absence of toxicosis manifestations, in particular nausea, does not indicate a developmental pathology; some women do not experience any signs of toxicosis throughout their entire pregnancy. Nausea is the body's reaction to preparing for the process of bearing a child and giving birth. It begins differently for each woman, usually it is the 5th week of pregnancy. It should be noted that an early onset of nausea in a pregnant woman subsequently entails severe manifestations of toxicosis, in which case the risks of excessive vomiting increase, the woman's inability to eat normally, such conditions require drug treatment.
In case of a singleton pregnancy, nausea will bother the woman until the 11th - 12th week, in case of a multiple pregnancy (two or more fetuses) until the 14th - 16th week.
Diarrhea
There are many reasons for diarrhea in pregnant women in the early stages. This may be due to a gastrointestinal disease or damage to certain organs (pancreas, stomach, etc.). In some cases, diarrhea is caused by general diseases. Diarrhea may begin with infectious diseases, poisoning, etc. It is known that the body of a pregnant woman is more susceptible to food toxins due to a weakened immune system. Also, unstable functioning of the nervous system due to hormonal changes, infection with worms, and lack of digestive enzymes may be the cause of this condition. The 5th week of pregnancy is the beginning of toxicosis, which can also affect the development of diarrhea in a woman.
Heartburn
The 5th week of pregnancy can begin with such an unpleasant condition as heartburn, which affects almost 80% of pregnant women. Heartburn usually begins to appear in the second half of pregnancy, when the pressure of the uterus on the internal organs increases, which contributes to the entry of gastric juice into the esophagus. Heartburn often begins after eating (or certain foods), it can last from a couple of minutes to several hours, attacks can bother several times a day.
At the beginning of pregnancy, the feeling of heartburn occurs due to hormonal changes. In pregnant women, the level of progesterone, which is responsible for reducing the tone of smooth muscles, increases. The hormone affects not only the woman's uterus, but also all internal organs. It is under its influence that the muscle between the esophagus and stomach weakens, which contributes to the entry of gastric juice into the esophagus.
It is generally accepted that in the early stages of pregnancy, heartburn is one of the symptoms of early-onset toxicosis, which usually goes away by the 4th month of pregnancy.
Herpes
Pregnant women may be susceptible to various types of herpes viruses. During pregnancy, herpes of the lips, skin, and genitals usually bothers. The genital form of the disease is the most dangerous at this time. Herpes infection can negatively affect pregnancy and the health of the unborn child, and cause a miscarriage. Characteristic signs of the disease are rashes on the skin and mucous membranes. Treatment usually involves local antiviral therapy.
Herpes often appears in pregnant women, since weakened immunity creates favorable conditions for the development of the virus.
If a woman becomes ill with herpes infection for the first time while already pregnant, the chances of microorganisms penetrating through the placenta increase many times over, but this does not always lead to infection of the child.
If a woman contracts the virus when she is 5 weeks pregnant, the chances of a spontaneous miscarriage and severe developmental defects (brain defects, hearing and vision defects, damage to the central nervous system, physical abnormalities) increase many times over.
If a woman had herpes before pregnancy, she is a carrier of the virus and her child is protected by antibodies produced by the mother’s body.
ARVI
The greatest danger to the unborn child is posed by viral diseases, especially influenza viruses. In the first three months of development, various developmental disorders may begin due to infection of the mother. The 5th week of pregnancy is a period when some defects may be incompatible with life, in which case the body rejects the fetus and the woman has a spontaneous miscarriage. But in some cases, the virus does not affect the small organism inside the woman, and the pregnancy proceeds safely.
After an illness, it is necessary to undergo an examination and take the necessary tests to ensure that no pathologies have occurred.
[ 12 ]
Runny nose
A runny nose in a pregnant woman is a common occurrence. Nasal congestion is caused not only by a weakened immune system, but also by a number of other reasons. In some cases, a pregnant woman has a runny nose almost the entire term. This condition is called vasomotor rhinitis (pregnancy runny nose), which is associated with hormonal changes. Usually, such a runny nose begins to bother a woman at the beginning of the second trimester, does not require special treatment and goes away on its own after childbirth.
If the 5th week of pregnancy began with constant sneezing, a severe runny nose, then allergic rhinitis may have begun. In this case, you need to contact a specialist for help. When, together with sneezing and a runny nose, the temperature rises, weakness, headache, cough appear - this indicates a viral infection.
Treatment with vasoconstrictors (naphthyzinum, pharmazoline, etc.) is not recommended for pregnant women. Such drugs also constrict the capillaries of the placenta, which causes hypoxia (lack of oxygen) of the fetus. Also, vasoconstrictors increase blood pressure and lead to spasms, which pregnant women should avoid. The condition of a runny nose can be tried to alleviate with the help of traditional medicine.
In addition to vasoconstrictor drops, nasal congestion can be relieved by rinsing the nasal mucosa with special solutions containing sea water (Saline, Aquamaris, etc.). It is also good to rinse the nose with chamomile or sage infusion, which have anti-inflammatory properties. Herbal infusions can also be used as nasal drops (2-3 drops several times a day).
Abdominal pain
Painful sensations in the lower abdomen at the beginning of pregnancy may appear due to hormonal changes in the body. The woman's uterus is just beginning to adapt to its new position. Usually, a nagging pain in the lower abdomen appears shortly before menstruation, and the 5th week of pregnancy is exactly the time when a woman expects menstruation.
If the pain does not go away after a few days, becomes stronger, you need to consult a gynecologist, if necessary, take tests. There are many reasons for painful sensations, and an experienced specialist will help you determine what exactly it is connected with. First of all, the doctor will advise you to take an hCG test and undergo an ultrasound examination. After receiving the results, you can already judge the causes of the pain. All of the above studies, first of all, will confirm (or refute) pregnancy. If the doctor does not see an embryo on the ultrasound (due to too short a period), then an increased level of human chorionic gonadotropin (hCG) will indicate pregnancy.
Abdominal pain in the early stages may occur when the location of the internal organs changes, which is associated with an increase in the uterus. In addition, the process of implantation and fixation of the embryo in the uterine cavity may be accompanied by nagging pain. Hormones can provoke increased bile formation, and in the future, when the gallbladder shifts to the right, the outflow of bile may be disrupted.
Pain in the fifth week of pregnancy may indicate a threat of miscarriage. During this period, the detachment of the amniotic sac begins, accompanied by painful sensations in the lower abdomen. As a rule, bloody discharge appears simultaneously with the pain. In this case, you need to consult your doctor as soon as possible; if the pain intensifies and becomes cramping, you need to immediately call an ambulance. In the first months of pregnancy, miscarriages are quite common; timely medical care in most cases helps to preserve the pregnancy.
When abdominal pain is accompanied by fever, it may be a sign of an ectopic pregnancy. In this case, you need to see a specialist as soon as possible, since the embryo is not attached to the uterus, but to the ovary or fallopian tube, and the growing embryo can cause organ rupture at any time.
Abdominal pain in early pregnancy often occurs when the uterus is in tone (tension). This happens because the muscles of the uterus contract intensely, which can cause a miscarriage. Due to the tone of the uterus, placental abruption may begin, and there may also be a delay in the development and growth of the embryo.
If the pain in the lower abdomen has stopped, this means that the dangerous period of consolidation in the mother’s body has been successfully completed, and a new stage of growth and development lies ahead.
Nagging pain in the lower back
The 5th week of pregnancy is accompanied by nagging pain in the lower back in many women. At this early stage, the uterus slightly increases in size, the fetus begins to actively gain weight, the woman's center of gravity shifts, and the load on the woman's lower back increases. During this period, the expectant mother may lack many vitamins and microelements, in particular calcium. Therefore, pregnant women are recommended a course of calcium with vitamin D.
Painful sensations in the lower back with elevated body temperature may be associated with the onset of pyelonephritis. With the onset of pregnancy, internal organs undergo changes in a woman's body without exception, and kidney-related diseases are quite common in pregnant women.
If you are bothered by a nagging pain in the lower back, you need to tell your doctor about it, who will help determine the cause of the pain and eliminate it. With each month, the load on the back will become greater, therefore, if there are no contraindications, you can do therapeutic exercises that will help strengthen the back muscles and reduce (or completely eliminate) pain in the lower back.
Ectopic pregnancy at 5 weeks of pregnancy
At an early stage, a doctor cannot always establish an ectopic pregnancy during an ultrasound examination. The level of the pregnancy hormone, hCG, will help to establish the presence of an ectopic pregnancy. The hormone appears in a woman's urine and blood from about the second week of conception and begins to increase rapidly. If an ectopic pregnancy is suspected, a dynamic hCG analysis is prescribed, which can determine the rate of growth of this hormone in the body. A lack of hormone or an insufficiently rapid rate of development may indicate the development of the embryo outside the uterus. The 5th week of pregnancy, which occurs outside the uterus, poses a threat to the life of a woman, since the growing embryo can at any time rupture the organ on which the attachment occurred (ovaries, fallopian tube).
In case of an ectopic pregnancy, surgical intervention is unavoidable, as the woman’s ability to conceive may depend on it.
Termination of pregnancy at 5 weeks
In modern medicine, there are 4 types of termination of pregnancy:
- Medicinal - with the help of special drugs, after which a woman begins to have a miscarriage, carried out at a period of up to 6 weeks;
- Vacuum or mini-abortion – performed up to 5 weeks;
- Surgical abortion – curettage of the uterine cavity, performed up to 12 weeks;
- Induced labor – follows the principle of normal labor (after taking special medications) and ends with standard curettage.
The 5th week of pregnancy is quite early, in this case the doctor can offer two options: medical or vacuum abortion.
During a vacuum abortion, the doctor performs the operation using a special vacuum suction device, under the strict control of an ultrasound machine. The operation is performed using local anesthetics and lasts no more than 10 minutes. After a mini-abortion, the healing process is relatively short, and most women do not experience severe pain.
Abortion with the help of medications consists of taking special pills (in the presence of a doctor). This type of artificial termination of pregnancy is carried out without surgical intervention in the woman's body and is considered the safest today.
Lifestyle and Safety
The 5th week of pregnancy is a critical time for the development of the child. Following several key rules will help protect the health of both the child and the expectant mother.
- Visit your doctor and keep appointments. Good prenatal care is essential for your baby's health. At your first prenatal visit (usually around eight weeks of pregnancy), your doctor will check for certain conditions that could lead to complications.
- Take vitamins. Most prenatal supplements contain more folic acid, iron, and calcium than standard multivitamins. Pregnant women need more of these nutrients.
- Taking folic acid is especially important during the first trimester as it reduces the risk of neural tube birth defects in the baby.
- Talk to your doctor about the medications you are taking. Many medications are unsafe to take during pregnancy. When you talk to your doctor, list any supplements or herbs you are taking.
- Stop smoking. Smoking increases the risk of miscarriage, placental problems, and interrupted labor. Smoking also slows fetal growth and increases the risk of stillbirth and infant death. Some studies have even linked smoking to an increased risk of cleft lip in children.
- It's never too late to quit smoking, every cigarette you give up gives your baby a chance to be born healthy.
- Avoid drinking alcohol. Just one drink a day can increase the risk of low birth weight and increase the risk of problems with speech, memory, concentration and language.
- Make sure your home and work are safe. Some jobs or hobbies can be dangerous for you and your developing baby. Exposure to chemicals, heavy metals, certain biological agents, or radiation can negatively affect your baby's health.
- Be aware that some cleaning products, solvents, and rust in drinking water from old pipes can also be harmful.
Alcohol
Just two weeks ago, when a woman had no idea about her condition, she could drink alcohol without harming the health of the future baby. But the 5th week of pregnancy is already a good enough reason to give up alcohol. During this period, a connection begins to be established between the mother's body and the child inside her. The fetus begins to receive almost all substances from the mother's body, including alcohol. Therefore, when pregnancy is confirmed, it is necessary to completely give up alcohol consumption, some doctors believe that the intake of alcohol-based drugs by a pregnant woman should also be excluded.
Drinking alcohol during pregnancy increases the risk of premature birth (quite often fatal for the baby), low birth weight. Excessive alcohol consumption provokes fetal alcohol syndrome - severe damage to the fetus (facial pathologies, physical and mental abnormalities, heart disease and other internal organs, behavioral disorders).
[ 20 ], [ 21 ], [ 22 ], [ 23 ], [ 24 ]
Smoking
Many women (especially those who did not plan to have a baby in the near future), having learned about their new situation, try to give up the bad habit so as not to harm the baby. But often a woman finds out that she is expecting a baby when the 5th week of pregnancy begins. The expectant mother can constantly worry about this, even if she stopped smoking at the first suspicion of pregnancy. Cigarette smoke contains a huge amount of harmful substances, in addition, its effect on the body blocks the access of oxygen to the baby, as a result, he simply stops breathing.
During the first week of embryo development, there is no common connection between the embryo and the mother, the embryo does not receive any substances from the mother's body - neither harmful nor nutritious. During the second week, the embryo is implanted in the uterine cavity and receives nutrition from its own reserves. Subsequent development of the embryo in the uterus forms a connection between it and the mother to receive nutrients from her body. Usually, by this time, the woman already knows about her pregnancy. If the woman smoked in the first weeks of pregnancy, this did not have a harmful effect on the baby, but smoking in the future can disrupt the function of the placenta and the child will begin to smoke at the same time as the mother, which will limit the supply of oxygen and nutrients to the body of the future person. Due to the mother's smoking during pregnancy, severe defects often develop: low weight, hypotrophy, the risk of cesarean section and stillbirth increases.
Nutrition
The diet of a pregnant woman should be different from what it was before. The diet of the expectant mother should include healthy and wholesome foods: fresh vegetables, fruits, greens, fish, dairy products. Hormonal changes may require completely unhealthy food (fast foods, fried foods, salty, spicy, chips, etc.), this should be taken calmly. If you really want something "interesting" do not suffer and deny yourself. For peace of mind, you can eat what you want, but only a little, otherwise this can lead to health problems in the future (for example, excessive consumption of salty foods can cause kidney dysfunction).
[ 25 ]
Vitamins
When the 5th week of pregnancy begins, the process of hormonal changes has already begun in the female body. During the first three months of pregnancy, all vital organs are formed, at this stage it is extremely important for a woman to receive a full range of vitamins and healthy nutrition. Folic acid and vitamin B9 are especially important in the first months of pregnancy, the lack of which can cause disturbances in the development of the nervous system and brain of the baby. The choice of vitamin preparations should be approached with extreme caution. Now in pharmacies there is an incredibly large selection of special vitamin complexes for pregnant women. A doctor will help determine the choice of vitamins, taking into account all the tests and the woman's condition.
Flights by plane
The reaction of a pregnant woman's body to a flight in the early stages of pregnancy is individual in each individual case. Everything depends on the gestational age, the recommendations of the attending physician, the woman's attitude to flights in general. Panic, fear, anxiety, which pregnant women often experience, are very harmful to the future child.
The 5th week of pregnancy is the period of toxicosis, so the likelihood that unpleasant sensations, in particular nausea, will increase on the plane increases. In addition, in the early stages of pregnancy, a flight (especially a multi-hour one) increases the risk of spontaneous abortion.
Activity
Choose a doctor and make an appointment. To prepare, write down the first day of your last menstrual period (this will help determine how far along you are) and start making a list of questions you have. Talk to relatives on both sides about family medical histories. Information about chronic and genetic diseases can help your doctor prevent certain conditions.
Sex
The 5th week of pregnancy can change a woman's libido. During this period, the reaction of hormones is unpredictable. Some women begin to feel a strong attraction to their husband, while others' desire disappears completely. If there is no threat of termination of pregnancy (pulling pain in the lower abdomen, bloody or brownish discharge), then there is no reason to refuse sex. A woman in her position must adhere to the principle that pleasure and enjoyment not only benefit the woman herself, but also have a beneficial effect on her future child.
The 5th week of pregnancy is a very important stage in the development of the embryo. During this period, the woman usually learns about her condition. The joy that the woman experiences at this time is already transmitted to her child, which has a positive effect on its development. In most cases, the woman does not yet experience any sensations associated with her new condition; in rare cases, early toxicosis may begin (nausea, dizziness, etc.). This week, a connection between the mother's body and her child already appears, it begins to depend on the woman's diet, her lifestyle, etc. In the 5th week of pregnancy, vital organs are laid down, so it is extremely important for a woman to control her emotional state, diet, lifestyle, so as not to provoke developmental defects.