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This period starts from the 29th week of the gestational period and ends with childbirth, which in most women with a full-term pregnancy occurs at 38-40 weeks. A child born as a result of premature birth at any time of the third trimester has every chance of successful development outside the mother’s body. By the end of the second trimester, he comes, having a weight of more than 1000 g, a height of more than 35 cm, almost completely formed organs and systems. Nevertheless, a full-term pregnancy and timely delivery is what every woman and the antenatal clinic leading her aspire to.
What does a woman feel in the third trimester
The uterus during this period increases significantly in size, the fetus grows. His movements occur more and more often, become more intense. A pregnant woman increasingly feels spasms of the myometrium, or Braxton-Hicks contractions. “Training” contractions are irregular, painless, lasting from a few tens of seconds to two minutes. If a woman changes body position, they most often stop. Increased contractions, occurring more than 4 times per hour, require medical supervision.
The bladder, as in the first trimester, functions much more often than usual due to the pelvic sagging and the enlarged uterus. A woman has frequent urination with small portions of urine.
Shortness of breath is a characteristic sign of the third trimester. Rapid breathing is caused by the uterus pushing the diaphragm up. To straighten the lungs with a deep breath, there is much less opportunity. Frequent shallow breathing helps a woman saturate the blood with oxygen, which should be enough to supply the placenta. Walking in the fresh air, airing the room will help facilitate the breathing process. A month before the birth, the uterus with the fetus will descend into the small pelvis, and there will be no shortness of breath.
More often than before, insomnia is felt in the third trimester. Uncomfortable and unusual positions for sleeping, the activity of the baby, most often attributable to the time of rest, do not make it possible to fully relax and sleep. To prevent insomnia, there are several simple remedies: a glass of warm milk before bedtime, listening to calm music, a walk in the fresh air.
A rapid increase in weight in the third trimester leads to a violation of the coordination of movements in a woman, inactivity, annoying clumsiness, awkwardness, and limited mobility. Lower back pain occurs due to the fact that the spine has to cope with the increased load. The increased mobility of the articular joints is caused by the action of progesterone, which is aimed at softening the ligaments and bones of the small pelvis to facilitate the process of childbirth.
In the third trimester, problems that appeared earlier can go – varicose veins, swelling of the extremities due to squeezing by the uterus of large blood vessels in the abdominal cavity.
What to do to alleviate the condition:
Change position more often, do not stand or sit in one position for a long time;
Do not wear high heels and flat shoes;
Do not sit with your legs crossed;
Use a small bench as a footstool;
Perform a complex of gymnastics for pregnant women;
Do not use a mattress that is too soft for sleeping.
At 37-38 weeks of the gestational period, the hormonal background of the body of a pregnant woman changes – the synthesis of estrogens increases. The signal for this is the maturation of the fetus and its readiness for extrauterine existence. Under the influence of estrogen, the tone of the uterus increases, its cervix changes. The cervical canal opens slightly, the cervix becomes shorter and softer, the mucous plug leaves – mucus mixed with blood.
Peak estrogen levels stimulate prostaglandin synthesis, triggering labor.
Fetal development in the 3rd trimester
An increase in the mass of the fetus leads to the fact that it no longer has such freedom of movement, cannot move freely in the uterine cavity. His movements stimulate short-term contractions of the myometrium – this is how the uterus stimulates the child to settle down with his head down for easier overcoming of the birth canal. The final position of the fetus takes on a period of 34-35 weeks of pregnancy. Later, he will no longer be able to roll over.
Seventh month (29-32 weeks of pregnancy)
The central nervous system of the fetus by this time was practically formed – the nerve endings were covered with a myelin sheath, all the convolutions appeared in the cerebral cortex with which a person will live his life. The sense organs have also matured, as the child reacts to sharp sounds and taste sensations, distinguishes the mother’s voice, touches himself, closes his eyelids, if a source of bright light is brought to the stomach.
Fetal parameters by 32 weeks of gestation:
Weight – 1700 g;
Height – 40-42 cm.
The general proportions of the fetus are increasingly approaching the proportions of a newborn child, it already has a sufficient supply of fatty tissue, the skin has become smooth, wrinkles have smoothed out on it. The respiratory system is already close to full maturation – surfactant accumulates inside the lungs, which does not allow the lungs to subside after exhalation.
The liver and kidneys are fully ready to perform their functions, the level of glucose in the blood of the fetus is regulated by the pancreas.
Eighth month (33-36 weeks of pregnancy)
The period of intensive weight gain of the child begins, every day it increases by 1% of the total body weight. The fetus swallows amniotic fluid, sucks its fingers, imitates respiratory movements, that is, it has developed basic reflexes: respiratory, swallowing, sucking.
The kidneys of the fetus daily excrete up to half a liter of urine into the amniotic fluid. The boys’ testicles descended into the scrotum. There are nails on the fingers and toes, on the hands they reach the tips of the last phalanx, on the feet they have not yet reached the end of the fingers.
Fetal parameters at 36 weeks:
Weight – 2300-2500 g;
Height – 44-48 cm.
The ears and nose of the unborn child have acquired the necessary elasticity, his body is covered with a thick layer of cheese-like lubricant, which will remain on the skin until the moment of birth and facilitate passage through the birth canal.
Ninth month (37-40 weeks of pregnancy)
The size of the fetus at the end of the gestational period in different women can vary significantly, this difference is due to hereditary characteristics, characteristics of the course of pregnancy, the condition of the placenta, full or insufficient nutrition of the woman during pregnancy.
Fetal parameters at the time of delivery:
Weight – 2500-4400 g;
Height – 45-56 cm.
The motor activity of the fetus is significantly reduced, turning and turning disappear. He has the ability to move his limbs, bend and unbend his arms and legs. The mode of sleep and wakefulness, combined with a decrease in movements, can alert a woman. However, most often there is no cause for concern, and in the evening the baby increases its activity.
Closer to the time of birth, only a minimal amount of cheese-like lubricant remains on the skin of the fetus, and fluffy hairs remain only on the shoulders. Depending on the type of presentation, the head or pelvis of the child descends and is pressed more tightly against the entrance to the woman’s small pelvis, preparing for the delivery process.
Signs of fetal maturity:
The tips of the nails reach the tips of the fingers;
The cartilages of the nose and ears acquire elasticity;
The boy’s testicles are in the scrotum;
The large labia of the girl overlaps the small ones;
Adipose tissue is developed;
The chest has a convex shape;
The umbilical ring is located in the middle between the womb and the navel.
Third trimester screening
In the period from 32 to 35 weeks of pregnancy, the third stage of assessing the condition of the fetus, placenta and uterus is carried out. It includes ultrasound, cardiotocography and tests to assess the fetoplacental complex.
To diagnose the condition of the placenta, a woman takes the following tests:
To determine the level. hcg;
To determine the level of placental lactogen;
To determine the level of free estriol;
To determine the level of progesterone.
Since the condition of the placenta is assessed in dynamics, these tests will have to be taken repeatedly during the screening period.
Cardiotocography (CTG) helps to determine the functional state of the child, especially his cardiac activity. Such an event will significantly reduce the risk of giving birth to a child with cardiopathology, and modernly identify fetal hypoxia.
Ultrasound is performed at 32-34 weeks of gestation, this is a mandatory screening item for the third trimester.
What does ultrasound evaluate?
Presentation of the fetus;
The functioning of the organs of the unborn child;
Child parameters;
Estimated date of birth;
Developmental defects of the fetus.
According to indications, dopplerography is performed to study blood flow in the placenta and the circulatory system of the mother and child.
Video about joint birth, about the development of the child, about the prevention of Rh conflict, about choosing a maternity hospital: