Third (3) trimester of pregnancy: which week begins and when it ends, advice from doctors

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What week does the 3rd trimester of pregnancy begin? The third trimester lasts from 28 to 40 weeks , in some cases childbirth occurs a couple of weeks earlier or later. During this period, the fetus continues to grow rapidly, the process is also accompanied by an enlargement of the uterus, the probability of termination of pregnancy is quite low. Weight gain intensifies, weekly it increases by 300-500 g, 5-7 kg is considered the norm.

Before giving birth, the process of weight gain slows down somewhat; a woman can even lose a few kilograms. The third trimester is often accompanied by edema, which can be caused by poor diet, hormonal imbalance, or the presence of salt in the body. Constipation, which occurs due to a sedentary lifestyle and general atony of the body, is also a common problem; in order to combat it, the doctor prescribes drugs based on natural fiber. Heartburn is not uncommon. If you are overweight in the 3rd trimester of pregnancy, you can stick to a light diet.

The last trimester is very important for mother and child , at this time it is recommended to pay very close attention to the menu, refrain from excessive consumption of salty foods, it is better to replace sugar with dried fruits. The expectant mother should visit a midwife or doctor once every two weeks.

When does the 3rd trimester begin?

The gestation period is counted by obstetric weeks and from the date of conception, which sometimes leads to confusion in terms. What week does the third trimester of pregnancy begin? worries many mothers, because this period is extremely important. In this regard, mommy’s calculations will differ from obstetric dates by about a couple of weeks. The third trimester begins from the twenty-seventh week of gestation. The countdown by obstetric standards begins from the moment the last menstruation begins, i.e. the 27th week of pregnancy, if counted from the first day of the last menstruation, is considered the actual beginning of the 3rd trimester of pregnancy. Now mommy has officially entered the final stage of pregnancy.

Embryonic periods differ from obstetric ones by several weeks, then at what week does the 3rd trimester of pregnancy begin in this situation. Since the embryonic period begins from the moment of conception, only ultrasound diagnostics can accurately determine it. If we take the generally accepted 2-week difference as a standard, then the beginning of the third trimester of pregnancy occurs, according to embryonic calculations, at week 25.

What week does natural childbirth begin?

Starting from the 37th week, doctors determined the date of natural birth. Up to 42 weeks, the birth of a child is considered normal. Most women give birth between 39 and 40 weeks. Boys are most often carried longer than girls: boys are born at 40 weeks or later, and girls at 38. Twins are born at 38 weeks. If natural labor does not begin before 43 weeks, doctors begin to independently stimulate labor using medications. Accelerating the birth process will not cause harm to the child, but a post-term pregnancy will not lead to good results. After all, the child will continue to grow, the skull will get stronger, and the brain will not receive enough oxygen.

How the baby develops

We found out when the 3rd trimester begins, now we need to consider some of the nuances of the baby’s development during these weeks. The third trimester of pregnancy is markedly different from other periods. The differences lie in the development of the baby and changes in the mother’s body, possible complications, etc.

By the end of 26 weeks of pregnancy, the baby reaches a size of 32-34 cm, its weight is about 0.85-0.95 kg. The baby is practically formed, and in the process of pregnancy in the 3rd trimester, the final improvement of his body will occur, such as the formation of subcutaneous fatty tissue, the appearance of the rudiments of permanent teeth, etc.

• The baby already recognizes his mother’s voice perfectly, he hears it and distinguishes it from the rest, so after birth he will never confuse this voice and will react to it first of all.
• The baby is already opening his eyes, and their muscles are already actively working. According to scientists, at this age the baby already dreams.
• During the 3rd trimester of pregnancy, the fetus moves quite actively inside, it stretches its limbs, turns over, and for the mother its every movement becomes more noticeable and sometimes more painful. Mommy already notices when the baby is active and when he sleeps off after vigorous activity.
• Pregnant women experience frequent movements at the beginning of this period, but over time the baby grows and becomes cramped. Therefore, at this stage, too frequent movements gradually end. They are now becoming rare, but much more powerful.
• If earlier the baby only pushed the mother, now it feels like the baby is deliberately kicking the stomach with all the strength of an infant. If you look closely at the exposed belly, you will notice its vibrations as the baby begins to roll over or kick again.
• Childbirth is rapidly approaching, and movements begin to be felt in the upper abdomen, where its limbs are located. This indicates that the baby has already taken the cephalic presentation necessary for a successful delivery. If painful kicks are felt below, this means that the fetus is positioned with the pelvis down.

If the baby’s activity suddenly ends unexpectedly, then the mother needs to inform the doctor about this. Usually the reason for such a long absence of movements is normal sleep, which a gynecologist can easily determine using CTG measurements that display the fetal heartbeat.

Third trimester: tests and examinations

Plan for visiting an obstetrician in the 3rd trimester of pregnancy:

• Up to 30 weeks – 1 time per month.
• From 30 to 36 weeks – once every 2 weeks.
• From 36 weeks until birth – once a week.

The schedule of doctor visits depends on the condition of the pregnant woman and her unborn child. If deviations from the norm are detected or dangerous factors are identified, the frequency of medical consultations is determined individually.

Admission includes:

• Clarifying the complaints of a pregnant woman.
• External examination with an assessment of the woman’s general condition: skin color, presence or absence of edema, condition of the mammary glands.
• Blood pressure measurement.
• Measurement of weight, abdominal circumference, fundal height of the uterus.
• Listening to fetal heart sounds using a stethoscope. The normal beat frequency ranges from 120 to 160 beats per minute. The heartbeat should be rhythmic and clear.
• Palpation of the fetus.
• Determination of uterine tone
• After 32 weeks - clarification of the baby’s position and presenting part.

Presentation is the relationship of the large part (head or buttocks) in relation to the entrance to the pelvis. Head presentation (physiological) is observed in 95-97%, pelvic presentation occurs in 3-5%.

Norms for the size of the uterine fundus height (UFH) and abdominal circumference (AC)

Weight gain

In the 3rd trimester, a woman gains weight at a faster rate than in previous periods. This is due to the active growth and development of the baby. Thin women gain up to 550 g per week, average build – 350 g, and plump women – 250 g.

At the end of pregnancy, the weight gain of the expectant mother is on average 10–15 kg, which includes:

• The weight of the baby, placenta, amniotic fluid is 5 kg.
• Uterus and mammary glands – 1-1.5 kg.
• Adipose tissue – 4 kg.
• Increased volume of circulating blood 1-1.5 kg.
• Extracellular fluid – 1-1.5 kg.

At 30 weeks before going on maternity leave, the pregnant woman is sent for mandatory tests, which include:

• General blood and urine analysis.
• Test for blood clotting factors - coagulogram.
• Determination of blood group and Rh factor.
• Blood test for syphilis, HIV infection, viral hepatitis.
• Testing urine for glucose.
• Vaginal smear for flora.
• ECG.

From 30-34 weeks, the pregnant woman undergoes a third screening ultrasound, which makes it possible to determine the height and weight of the fetus, its position in the uterus, assess the condition of the placenta, the quantity and quality of amniotic fluid, and identify the presence of malformations or entanglement of the umbilical cord.

In addition, a pregnant woman visits a therapist and dentist, and, if indicated, other specialists.

From the 33rd week of pregnancy, cardiotocography of the baby (CTG) begins. This method allows you to evaluate the work of the heart, as well as record its motor activity and trace the connection between contractions of the uterus and the baby’s reactions to them. CTG reveals uterine hypertonicity and oxygen deficiency in the baby. Additionally, to determine the causes of hypoxia, Dopplerography of the vessels of the mother-child system is prescribed.

Changes in the mother's body

With proper care you can avoid stretch marks

It is difficult to say exactly how many weeks the tummy begins to grow, because much depends on the patient’s constitution. But it is absolutely known in which trimester the belly of pregnant women is rounded the most. In the weeks of the last trimester, the most intense weight gain is observed, which generally reaches 12-15 kg.

At 27-28 weeks, mothers begin to complain of shortness of breath and frequent heartburn, lumbar pain and a forced awkward manner of walking. In addition, mothers note noticeable mobility of joint tissues and severe discomfort from the baby’s kicks, up to painful spasms that occur if the fetus hits neighboring internal organs such as kidneys, liver, etc. Such symptoms are temporary; when observing pregnancy week by week, it takes a very short time time. The baby just grew up significantly and began to involuntarily put pressure on neighboring organs.

Useful tips

Simple recommendations from experts will help make the third trimester easier.

• Move more, do gymnastics, walk, walk, do feasible housework . Movement is not only life, but also effective preparation of the cervix for childbirth.
• Change your diet - add more vegetables and fruits, reduce the amount of foods high in calcium , it is better to replace red meat with fish or chicken breast.
• If the expected weight of the fetus is large, avoid taking multivitamins in the third trimester.
• Monitor your well-being . If there are signs of the mucous plug coming off or water leaking, intimate contacts and taking a bath are prohibited, and if regular contractions or water leakage occur, you should go to a maternity facility.
• Diseases such as influenza or chickenpox at this stage are dangerous not so much for the baby as for his mother, since they aggravate her already difficult condition. Therefore , you should avoid contact with sick people , and also pay enough attention to the prevention of infectious diseases.
• It is important to carefully count the movements every day . If there are suddenly few of them, or the baby, on the contrary, behaves too actively, you need to consult a doctor - both of these can be signs of hypoxia, that is, oxygen starvation of the baby.
• Practice proper breathing and exercises to relieve labor pain . This can be learned in courses for pregnant women, available free of charge in every antenatal clinic.

Do not try to induce labor yourself or speed it up at home.

medical reviewer, psychosomatics specialist, mother of 4 children

Source of the article: https://o-krohe.ru/beremennost/3-trimestr/s-kakoj-nedeli-nachinaetsya-i-kogda-zakanchivaetsya/

The danger of gestosis

Preeclampsia is considered one of the dangerous complications of late pregnancy. What do girls need to know about this condition? In fact, gestosis is a late-term toxicosis and negatively affects the activity of vascular structures, the brain or the kidneys. Preeclampsia is especially common at 6-8 months of gestation in patients with endocrine, cardiovascular, hepatic, renal pathologies, obesity or unhealthy habits.

Preeclampsia also often affects patients who are prone to stress and depression, who often give birth or have previously had artificial abortions. Gestosis often begins in pregnant women under 18 or over 35 years of age, as well as in those who have already suffered from this pathology in the past or are carrying twins, in first-time mothers and those living in poor environmental conditions. Characteristic signs of late toxicosis are hyperedema and nephropathy, the presence of protein in urine and preeclampsia, and in especially dangerous cases, eclampsia.

Although the pathology refers to toxicosis, it can seriously affect the fetus, and extremely negatively. What does not have the best effect on pregnancy:

• Preeclampsia can lead to premature delivery;
• At times, this pathological condition provokes acute oxygen starvation of the baby or fetal hypoxia already in the first week;
• Preeclampsia is also fraught with delays in intrauterine development.

To avoid such serious consequences, you need to thoroughly prepare for such circumstances, reducing the occurrence of gestosis to a minimum. To do this, girls need to regularly go for routine gynecological examinations, take their diet more seriously and not eat whatever they want, especially salty and smoked foods, fatty and fried foods. And remember, pregnancy at any week is simply a physiologically special condition, but not a disease. It does not need to be carried in bed unless the doctor gives such recommendations. Try to move more, walk, especially before bed.

During pregnancy, it is imperative to monitor your weight; the body is already under increased stress, so there is no need to put extra pounds on it. It would also be useful to monitor the pressure; usually with gestosis it is increased and is different on both arms. Don’t forget to give your urine in a timely manner; in case of gestosis, protein is found in it, and also go for routine gynecological examinations.

Nutrition in the third trimester of pregnancy

Nutrition in late pregnancy is of great importance for the normal well-being and full development of the child. Now the baby is almost formed and is actively gaining weight, the mother’s task is to “provide” him with the nutrients and beneficial substances necessary for this. Thus, nutrition in the third trimester of pregnancy must include a daily intake of protein, the source of which is boiled lean meat and fish. But a pregnant woman should be careful with fish: some types of fish contain quite a large amount of mercury, which is harmful to the baby. The optimal “option” for a woman is cod, salmon, tuna, but it is better to avoid king mackerel. Again, eggs, dairy and fermented milk products will provide your baby with protein and additional calcium.

It is advisable to enrich your diet with fresh vegetables and fruits - a sufficient amount of fiber will prevent constipation, and vitamins and minerals will maintain vitality and the body in good shape. Useful foods for pregnant women at any stage, including in the third trimester of pregnancy, are beef, beef liver, pomegranate and tomato juice, which maintain hemoglobin levels and prevent the development of anemia.

It is better to avoid flour products, confectionery products, sweets, and sweet soda for a while - they can provoke additional weight gain, which is undesirable during pregnancy. In addition, you should exclude fatty and spicy foods from your diet: in addition to the fact that such food can cause heartburn, it also retains fluid in the body and the development of edema. To avoid such a situation, you should limit your salt intake, and also carefully maintain a water-drinking balance: the amount of liquid consumed per day should not exceed 1.5 liters, including juices, soups, milk, and fruits.

It is better to take food in fractions, often and in small portions, eating when there is a need for it. Food should be healthy and natural; it is better to avoid fast food and all kinds of semi-finished products. In general, your daily calorie intake should be about 3,000 kcal.

Other complications

Don't forget about healthy foods

Unfortunately, when managing pregnancy week by week, it can be noted that in each week of the third trimester a woman may experience some serious challenges. What dangers and inconveniences can this period of gestation bring? Firstly, nausea. If in the first months this symptom indicated the development of toxicosis, now nausea reactions are a consequence of the pressure of the enlarged uterine body on neighboring organs. If nausea is associated with severe edema and an increase in the pregnant woman’s body weight, then this symptom should be considered as a sign of gestosis. In this situation, you need to consult a doctor for urgent treatment.

Secondly, shortness of breath, it occurs even during normal movement around the apartment, not to mention walking down the street. Many mothers wonder how many weeks they will have to endure such torment with shortness of breath and dizziness. Experts say that such sensations will last almost until childbirth, because the uterus grows and puts pressure on the diaphragm, which prevents the mother from breathing fully. Usually, before delivery, the uterus drops down, which makes breathing easier, but then another problem is added - severe nagging pain in the lower back and groin - this is how the pressure of the uterus manifests itself.

Thirdly, almost no late pregnancy is complete without heartburn. It begins differently for everyone, for some in the first week of the third trimester, for others just before childbirth. There is no specific therapy for this condition, so you just have to endure it. When the uterus descends, this unpleasant symptom will no longer bother you.

Also common problems of late pregnancy include hyperedema, frequent urination and constipation. Frequent trips to the toilet are explained by the pressure of the uterus on the urinary tract, constipation is also associated with pressure, only on the gastrointestinal tract structure. In the latter case, you need to eat fermented milk products and vegetables with a high fiber content, drink more plain water, then constipation will not bother you.

Pain symptoms in the third trimester

Painful sensations in pregnant women in the last trimester of pregnancy deserve special attention. They should be treated with the utmost caution, because the third trimester of pregnancy may well end in premature birth.

1. Painful symptoms are localized in the sacral bones and articulation. This symptom is quite common among mothers and indicates that active preparation for childbirth is taking place. To reduce the severity of pain, mothers are recommended to wear a prenatal bandage to support the tummy and relieve stress on the vertebral structures.
2. Painful sensations in the lower abdomen - such a symptom may indicate a dangerous condition - hypertonicity of the uterine body, and these symptoms should not appear until 38 weeks. If a girl’s stomach turns to stone and the pain intensifies, then this indicates the beginning of a premature delivery process, i.e., childbirth.
3. Headaches are also considered quite common. Migraines can be explained by increased blood pressure, worries about childbirth, or lack of sleep.
4. Leg pain. Usually this symptom appears after long walks, it’s just that the weight now quickly increases, the center of gravity changes, and therefore painful discomfort occurs. Therefore, the third trimester of pregnancy requires the mother to rest more and wear flat shoes.

If the pain bothers you very much, you should not reach for the first aid kit and look for painkillers. When pregnant, it is generally best to avoid the pill. Try to lie down in a comfortable position, sleep a little, you can put a cool compress on your forehead or lubricate your temples with an asterisk. Usually, after a short rest, all unpleasant symptoms disappear. If abdominal pain does not go away, you need to urgently consult a doctor.

What to do if you have a cold?

Colds are quite dangerous for expectant mothers, however, you cannot protect yourself from them. In case of illness, the treatment process cannot be delayed, because a prolonged cold can provoke premature birth. The problem with treatment is the ban on taking most medications. First of all, for treatment, mothers need to remain in bed, and use herbal decoctions and saline solutions as medications. However, not all herbs can be used, so it is better to discuss the choice of medication with your doctor. In order to reduce the likelihood of a cold, mothers should dress warmly, avoid drafts and large crowds of people. By adhering to safety measures, mothers will be able to make their life and the life of their baby easier.

Recommendations from experts

Chamomile tea is one of the best drinks

So, at the third stage of gestation, active preparation for childbirth begins, the pelvic bones gradually move apart, the uterine body descends into the small pelvis, etc. During this period, it is very important for mom to monitor her diet and other areas of life. Just don’t take everything so narrowly and go on a diet. Fasting is unacceptable for mommy. You just need to eat in a balanced manner so that your diet contains the optimal amount of microelements, vitamins and nutritional supplements. It is necessary to limit cakes and bakery products, pastries and pastries as much as possible. These products contain a lot of easily digestible carbohydrates and fats, which lead to a quick gain of extra pounds.

The drinking regime also deserves attention, and drinks such as tea and alcohol, coffee and energy drinks, and sweet sodas are prohibited for pregnant women. The caffeine contained in most of these drinks causes an increase in tone and performance, increases blood pressure and increases the pulse rate - all this negatively affects the well-being of the fetus, impairing its blood supply. Alcohol has a toxic effect on the baby, poisoning his entire body. Therefore, while the birth is approaching, mommy can only drink plain water, compotes or fruit drinks, herbal teas from chamomile or rose hips, natural juices, etc.

The changes that occur at this stage significantly limit the patient’s motor capabilities. Excess weight causes back pain, so even simple walking can cause a lot of discomfort such as shortness of breath, clumsiness of gait, pain in the legs, etc. But some mothers who were actively involved in sports before conception maintain their shape while carrying a baby. Experts say that during pregnancy, water treatments in the pool, regular walking, fitness for pregnant women or gymnastics are useful. These workouts will help keep your body in shape and make childbirth easier.

It is worth mentioning separately about the intimate side of married life. Until how many weeks can spouses have sex? Doctors say that there are no restrictions on sexual activity at 27-42 weeks of gestation. Spouses may well fulfill their intimate needs to the extent necessary for them, the main thing is that intimacy does not cause discomfort to the girl and does not cause painful sensations or other unpleasant consequences. And never forget that sexual intercourse is a powerful stimulant that triggers labor.

Peculiarities

The onset of the final third of the pregnancy period for a woman means that the easy period has ended, and now, for understandable physiological reasons, it will be more and more difficult every day to bear the baby. The child has reached a large size, he continues to grow and gain weight, the woman herself has also gained a fair amount of weight. By 35-36 weeks the uterus reaches its maximum size - it has nowhere else to grow.

It is the large uterus that causes discomfort in the third trimester. It puts pressure on the diaphragm, which leads to shortness of breath, compresses the woman’s stomach, which sometimes leads to unbearable heartburn, the compressed intestines cannot function fully, which causes constipation and exacerbation of hemorrhoids. Load on the spine leads to back pain, load on the legs leads to pain in the lower extremities, and sometimes to varicose veins. The picture of everyday life of the expectant mother is complemented by the influence of hormones - relaxin leads to softening of the bones and ligaments of the pelvis, which causes pain in the coccyx and pubic bone, accumulating oxytocin intensifies training contractions, anxiety and fears return, and depression may develop.

The child is fully formed, he is well protected, so at the current stage he is in almost no danger. You can now take many medications that were previously prohibited.

The main danger at the current stage lies in the possibility of fetal hypoxia, because from the 34th week the placenta reaches its maximum degree of maturity and begins to age, copes with its responsibilities worse.

There is no need to rush things - although the last weeks of pregnancy are difficult for the mother, they are necessary for the baby: the process of accumulation of surfactant in his lungs, which is necessary to ensure the possibility of independent breathing, is completed; the weight gained by the baby is not only plump cheeks and butt that are pleasant to the eye, but also the possibility Effectively regulate your body temperature, keep warm after birth. These two signs are extremely important for a child at birth. It is in the last weeks, starting from 32-34 weeks, that the baby begins to undergo the most important process of learning adaptability - he will have to change his habitat, and his little body will activate adaptive abilities in advance.

Difficulties that women may encounter during this period:

• anemia;
• gestational pyelonephritis;
• fetal hypoxia;
• gestosis.

Following all doctor’s recommendations will help to eliminate such complications.

Dangers of the third trimester

At the third stage of pregnancy, very serious dangers can await the mother. Therefore, you need to know their signs in order to prevent danger in a timely manner. So, let's start with the most common problems like premature birth, leakage of amniotic fluid or placental abruption.

• Premature birth. If the baby appears before 38 weeks, then he is considered premature, and the delivery has the status of premature. This can happen with excessive physical activity and psycho-emotional experiences, severe stressful situations, or taking medications that promote uterine contractions. Premature labor is manifested by pronounced contractions at regular intervals. You need to urgently call an ambulance, otherwise you could lose your baby.
• Placental abruption. A similar dangerous condition occurs when falls, blows to the abdominal area, severe gestosis or hypertension in a pregnant woman, as well as against the background of endocrine pathologies. Characteristic signs of placental abruption are acute, severe pain and bleeding, accompanied by fainting, weakness and nausea. An ambulance is also required.
• Premature rupture of water. Also a common complication in the last months of pregnancy. If there are no contractions, cervical dilatation and bleeding, then obstetricians prolong pregnancy. If the fetus experiences hypoxia due to a lack of amniotic fluid or an infection occurs, then a cesarean section is performed or doctors stimulate delivery with specialized medications.

Changes in the third trimester of pregnancy affect absolutely all organic and vital areas of the patient. Mommy's life changes significantly at this stage. If earlier the mother was in some kind of prostration and euphoria, now she clearly understands that soon she will have a baby, who does not forget to remind her of this by pushing and kicking her mother’s belly and ribs. At this time, you need to be more attentive to any changes in your well-being. A serious attitude towards pregnancy will help the birth take place on time and without complications, and the baby will be born strong and healthy.

Ultrasound in the third trimester of pregnancy

Ultrasound in the third trimester of pregnancy is a mandatory routine examination, usually performed at 32-34 weeks. The task of the last, actually “prenatal” ultrasound examination is to assess the development of the baby’s organs and systems, as well as to determine the readiness of the mother’s body for the upcoming birth. So, during an ultrasound in the third trimester of pregnancy, the doctor assesses the size of the fetus and confirms the date of birth, determines the correspondence of fetal development to the scheduled date of delivery.

The presentation of the fetus is determined during an ultrasound examination, which makes it possible to determine the tactics of labor management (breech or pelvic presentation may become an indication for cesarean section). The purpose of ultrasound in the third trimester of pregnancy is also to determine the degree of maturity of the placenta and its location, assessing the uteroplacental and fetoplacental blood flow.

As in earlier stages, in the third trimester of pregnancy, ultrasound can detect congenital malformations of the fetus. Although gross pathologies can be determined during the first and second planned ultrasound, some diseases of the baby, for example, renal hydronephrosis (fluid in the kidneys), appear only towards the end of pregnancy. Having identified this or that pathology, the doctor will be able to decide on further tactics: a premature delivery may be necessary or a decision will be made on surgical intervention immediately after the birth of the child.