The third trimester
3rd trimester, 3rd trimester of pregnancy
Under the term “3. Trimester “means the third stage of pregnancy. The 3rd trimester begins with the 29th week of pregnancy and lasts up to the 40th or 42nd week of pregnancy.
Course of the 3rd trimester
From a medical point of view, pregnancy is divided into three roughly equal parts, the so-called thirds of pregnancy (trimesters). Each of these thirds of pregnancy is characterized by a different stage of development of the unborn child. In addition, the expectant mother may experience specific symptoms in each trimester of pregnancy.
From the 29th week of pregnancy onwards one speaks of the 3rd trimester. This is enough, depending on the date of birth, up to the 40th or 42nd week of pregnancy. During the third trimester of pregnancy, the unborn child increases significantly in size and weight. In addition, the internal organs of the unborn child are mature enough to be considered viable. This means that the chances of survival in the event of a premature birth after reaching the third trimester are very high. Nevertheless, it can be assumed that every single day within the womb is valuable for the development of the unborn child.
In addition to the progress of the child's development, there are also far-reaching changes in the mother-to-be in the third trimester of pregnancy. In general, it can be assumed that the organism of the expectant mother has already adapted to the needs of the growing child at the beginning of the second trimester of pregnancy. For this reason, the hormone-related pregnancy symptoms for most women already decrease significantly in the 13th week of pregnancy. The symptoms that typically occur in the third trimester of pregnancy are therefore usually not related to the hormonal changes in the expectant mother. Rather, the growing size and weight of the child can become very difficult for the mother in the 3rd trimester.
Since the body gradually prepares for the upcoming birth during this third of the pregnancy, it is advisable for the expectant mother to clarify all questions regarding the birth. Women planning to give birth spontaneously should also remember to attend a dedicated antenatal class, which ends approximately six to eight weeks before the due date.
Discomfort in the third trimester
Most of the symptoms that typically occur in the third trimester of pregnancy are usually not directly related to the initial hormonal change. Nevertheless, even in the third trimester of pregnancy, the expectant mother can occasionally experience hormone-induced symptoms.
Mood swings in particular are not uncommon in the third trimester of pregnancy. In some women, these mood swings in the 3rd trimester are even characterized by sudden onset of crying attacks for no obvious cause.
In addition, it can be observed in the expectant mother that the waist circumference increases significantly within days within this third of the pregnancy. The reason for this is the rapid increase in the size and weight of the unborn child. Due to the steadily increasing waist size, it is becoming more and more difficult for the expectant mother to find a relaxed position to sleep. This often leads to problems falling asleep and staying asleep (see also: Difficulty falling asleep). Affected women can often remedy the situation by using a side sleeper or nursing pillow. This can be pushed between the bent legs and thus help relieve the stomach and spine.
Since the child's steady growth also begins to displace the mother's internal organs, further symptoms typical of the third trimester of pregnancy can arise. Many women often experience heartburn, stomach pain and / or constipation during this stage of pregnancy (Constipation). In the course of the child's growth, the abdominal organs are pushed further and further towards the chest. As a result, there is also a narrowing of the organs of the chest. While the apex of the heart is pushed further and further towards the head, the lungs initially decrease in volume. For this reason, shortness of breath and exertion-dependent shortness of breath are also typical symptoms in the 3rd trimester of pregnancy.
One of the other classic symptoms of this third of pregnancy can be observed in many women within the 1st trimester. If there is an increased urge to urinate early on, this will increase significantly in the course of the third trimester. The reason for this is the fact that the growing child presses the bladder more and more and compresses it more and more. In addition, it happens that women can no longer hold the urine if there is a sudden increase in pressure in the abdomen, for example when coughing, laughing or sneezing. For this reason, unwanted urine loss is one of the typical symptoms in the 3rd trimester of pregnancy.
In addition, many expectant mothers develop back pain during the third trimester of pregnancy. This typical complaint is caused by a combination of an increase in the progesterone concentration and child growth. While the unborn child steadily increases in size and weight in the third trimester, the pregnancy hormone progesterone induces the loosening of the ligaments and muscles. This process is essential for the approaching birth, but it causes increasing stress on the spine. For this reason, most women in the 3rd trimester of pregnancy suffer mainly from complaints in the lumbar spine area.
Read more on the topic: Back pain in pregnancy
Furthermore, so-called practice contractions are among the typical complaints in the 3rd trimester of pregnancy (please refer: Premature labor). However, practice contractions do not necessarily have to be accompanied by pain. Some women only experience painless contractions of the uterine muscles from around the 28th to 34th week of pregnancy. Expectant mothers do not need to worry about the occasional practice contraction. However, a doctor or midwife should be contacted urgently if such labor pains occur more than three times an hour or ten times a day.
Nausea in the third trimester
If nausea and / or vomiting occurs frequently in the third trimester of pregnancy, this can usually be associated with the steady growth of the unborn child. Since the space in the abdomen is limited despite the increase in the circumference of the abdomen, the internal organs are increasingly pushed towards the chest. For this reason, the expectant mother's gastrointestinal tract is increasingly compressed. This can lead to severe nausea and even vomiting, especially after eating. To counteract the nausea, it is advisable to eat several small meals throughout the day. Nausea can be observed in expectant mothers in the 3rd trimester, especially when the stomach is excessively full.
Read more on this topic: Nausea in pregnancy
Development of the child
The development of the child's internal organs is usually complete before the beginning of the third trimester of pregnancy. In the course of the 3rd trimester, the unborn child only needs to continue to gain size and weight. For this reason, it is assumed that a child will be able to survive at the beginning of the third trimester of pregnancy. This means that the chance of survival in a premature birth is now very high. Nevertheless, every additional day in the womb is considered a gain for the development of the unborn child. The reason for this is the fact that the child's immune system undergoes extensive maturation processes in the third trimester of pregnancy. In addition, a newborn child with sufficient body weight has been shown to be able to regulate its body temperature better. For this reason, children who were born before the 37th week of pregnancy often have to be placed in a so-called warm bed for days.
With the beginning of the 3rd trimester of pregnancy, the child's movements become increasingly clear. In most cases, during the third trimester, it is even possible to see the unborn child kicks through the abdominal wall. However, as the child gains size and weight very quickly in the 3rd trimester, the space in the uterus decreases from week to week. For this reason, the child's movements also decrease significantly at the end of the third trimester of pregnancy.
By the time they reach the 40th week of pregnancy, the unborn children have an average size of 50 to 51 centimeters and a weight of around 3,500 grams.
Screening in the third trimester
Regular screening, the so-called third trimester screening, also takes place in the third trimester of pregnancy. The main purpose of this screening is to monitor child growth and identify possible problems at an early stage. In addition to the vaginal examination with assessment of the external cervix, the ultrasound examination as part of the third-trimester screening also plays a decisive role. If a premature shortening or opening of the cervix is suspected, a transvaginal ultrasound should be performed during the screening. In this way, the actual length of the internal cervix can be determined and treatment can be initiated at an early stage if necessary.
Furthermore, an abdominal ultrasound (i.e. an ultrasound examination through the abdominal wall) is carried out during the screening in the third trimester of pregnancy. This part of the screening in the 3rd trimester primarily assesses the growth and development of the unborn child.
In addition, placental function and the location of the placenta should be re-determined during screening in the last trimester of pregnancy. Under certain circumstances, a test of the blood flow of the maternal (especially the uterine vessels) and the child's (especially the umbilical cord vessels) blood vessels may be useful during the examination. The vessels are usually examined using Doppler ultrasound.
In addition, screening in the 3rd trimester of pregnancy includes re-examination of the unborn child's organs. If there are any abnormalities at this point in pregnancy, a suitable maternity clinic can be sought at an early stage. The screening in the 3rd trimester of pregnancy therefore serves as the final check-up before the impending birth.
Read more about this: Pregnancy check-ups
The third trimester of pregnancy begins at the 29th and ends at the 40th week of pregnancy. Since some children stay in the womb much longer, the 3rd trimester of pregnancy can well extend to the 42nd week of pregnancy. At the latest by the end of the 42nd week of pregnancy, however, the initiation of childbirth should be considered. Otherwise it could lead to a dangerous situation for mother and / or child. While the organs of the unborn child have matured further in the second trimester of pregnancy, in the third trimester of pregnancy all that is needed is some time to gain size and weight.
In general, one can therefore assume that the unborn child will be viable by the beginning of the third trimester. This means that the probability of survival at this point in time is very high, even with a premature birth.However, children born between the 29th and 37th week of pregnancy often require medical attention. In particular, independent breathing and the regulation of body temperature can still be problematic in children born before the 37th week of pregnancy.
While the growth of the child is in the foreground in the third trimester of pregnancy, there can be major changes in the expectant mother. As the child grows, the waist circumference increases rapidly. For this reason, many women develop stretch marks on their stomach and / or chest in the third trimester of pregnancy.
In addition, back pain and frequent urination are typical symptoms in the 3rd trimester of pregnancy. Above all, the increasing pressure on the urinary bladder can be very stressful for the expectant mother. In most women, a frequent need to urinate is noticeable as early as the second trimester of pregnancy. In the 3rd trimester of pregnancy, sudden increases in pressure in the abdomen, for example when coughing, sneezing or laughing, can even lead to unwanted urine leakage.