Second trimester, second trimester of pregnancy
Definition
The term “2nd trimester” refers to the second stage of pregnancy. The 2nd trimester begins with the 13th week of pregnancy and ends with the beginning of the 28th week of pregnancy.
Course of the 2nd trimester
The human pregnancy is divided medically into three approximately equal sections, so-called trimesters. Each of these trimesters is characterised by a different stage of development of the unborn child. In addition, the expectant mother may also experience different symptoms during the different trimesters.
While the first trimester begins before the actual pregnancy begins on the first day of the last menstrual period, from the 13th week of pregnancy onwards it is called the second trimester. Already at the beginning of the 2nd trimester of pregnancy, the body of the expectant mother has usually become accustomed to the hormonal changes. At this time, the organism is already optimally adjusted to the development of the unborn child.
For this reason, it can be observed in most women that the initial pregnancy symptoms clearly subside or even disappear completely. For this reason, many women agree that the 2nd trimester is the most pleasant third of pregnancy. On the fetal side, the period of rapid growth begins with the 13th week of pregnancy.
Both the height and the weight of the unborn child increase significantly every week during this trimester. For this reason, most expectant mothers notice a significant growth of the baby’s abdomen within the 4th to 6th month of pregnancy at the latest. However, how fast the abdomen actually grows during pregnancy varies greatly from woman to woman.
Changes and complaints in the second trimester of pregnancy
By the end of the 2nd trimester of pregnancy at the latest, even outsiders can see that new life is growing in the womb of the expectant mother. The body of the expectant mother is well adapted to the pregnancy at this time. By the beginning of the 2nd trimester of pregnancy the placenta is so mature that it can produce the pregnancy-maintaining hormones on its own.
The concentration of the pregnancy hormone beta-hCG also decreases significantly during the 2nd trimester. For this reason, it can be observed in most expectant mothers that the initial symptoms clearly subside. In most women the typical symptoms of early pregnancy even disappear completely by the end of the 12th week of pregnancy.
Especially the end of the dreaded morning sickness makes the further pregnancy much easier for the women concerned. From the 2nd trimester onwards, the unborn child is supplied completely via the placenta. For this reason, the expectant mother may experience different symptoms.
Due to the pregnancy-related increase in blood volume, an increased heart rate of about five to ten beats per minute can be seen. For the expectant mother, this accelerated heartbeat at the beginning of the 2nd trimester can be somewhat disconcerting and worrying. In fact, however, these are only subjective complaints that have no disease value whatsoever.
The increased growth of the mammary glands can also lead to complaints in some women in the 2nd trimester of pregnancy. Around the 16th or 17th week of pregnancy, the mammary glands begin to produce the so-called “first milk”. Under certain circumstances, this may already leak from the breast unintentionally in the 2nd trimester.
Due to the growth of the mammary glands, a slight pulling in the breasts is also one of the typical complaints of the 2nd trimester of pregnancy. Due to the steady growth of the child, the abdominal organs are increasingly displaced towards the rib cage. Especially the intestine and stomach are often compressed in the course of this process.
For this reason, digestive problems are among the typical complaints of the 2nd trimester of pregnancy. As the weight of the unborn child increasingly presses on the bladder, frequent urination is also one of the typical complaints in the 2nd trimester of pregnancy. Some pregnant women may even involuntarily leak urine when coughing or sneezing.
Affected women can often alleviate these symptoms by regular training of the pelvic floor muscles. In addition, the development of vein problems and varicose veins is one of the most common complaints in the 2nd trimester of pregnancy. These complaints mainly affect women who are frequently standing despite existing pregnancy.
Due to the increasing magnesium requirement, sensitivity disorders (such as stinging or burning) and muscle cramps in the legs can also occur. As the unborn child steadily increases in size and weight during the 2nd trimester of pregnancy, the connective tissue and epidermis of the expectant mother can be affected. Many women therefore develop reddish or brownish stretch marks (stretch marks) during the 2nd trimester of pregnancy.
By the beginning of the 2nd trimester of pregnancy, all organs of the unborn child are already in place. However, within this third trimester of pregnancy they increase in size and continue to mature. In addition, both the gastrointestinal tract and the kidneys begin to work in the 2nd trimester of pregnancy.
While the head in the 1st trimester of pregnancy was disproportionately large in relation to the extremities, ribcage and abdomen, its proportions will adjust in the course of the next few weeks. In addition, in the 2nd trimester the child starts to drink amniotic fluid and pass it as urine. Since the lungs are not yet fully developed and the alveoli are not yet unfolded, the unborn child continues to be supplied with oxygen via the placenta.
Already at the beginning of the 2nd trimester of pregnancy, the external sexual organs begin to differentiate. With particularly high-resolution ultrasound equipment, the sex of the child can be determined from the 14th week of pregnancy. However, most gynaecologists wait until the announcement of the sex until the 16th or 18th week of pregnancy.
The child’s bones are also compacted and hardened by the storage of calcium. In addition, the sensory organs begin to work. The unborn child can already hear the mother’s heartbeat within the first weeks of the 2nd trimester.
Around the 18th week of pregnancy, sounds from outside (for example, the mother’s voice) can also be heard. It can also be assumed that the unborn child can tell the difference between light and dark in the 2nd trimester of pregnancy. At the end of the 2nd trimester of pregnancy, the child’s hair begins to grow.