The third trimester of pregnancy has begun, and the woman is mentally preparing for the most important event in her life - the birth of a child. At 30 weeks, an ultrasound scan may be recommended. Next, we will talk about how the child looks now and what the ultrasound indicators can tell about him.
The purpose of the survey
Ultrasound diagnostics does not belong to the category of routine examinations this week. An ultrasound scan at 30 weeks of gestation is prescribed outside the plan. The first two screening studies are in the past, until the third for at least a couple of weeks. Some of the expectant mothers during this period are sent to the ultrasound diagnostic room of their own free will to see if everything is in order with the child. Gynecologists even joke that the best sedative for a pregnant woman is a visit to the ultrasound doctor.
However, there may be medical indications for the examination. These include suspicions of pregnancy pathology. Weak and rare fetal movements, which are already counted daily at 30 weeks, as well as too active movements, sharp jerks of the baby, can become the basis for a pregnant woman to be sent for an ultrasound scan unscheduled.
The task of the examination in this case is to exclude the entanglement with the umbilical cord, hypoxia, and other unsuccessful conditions that can pose a threat to the life and health of the child.
Ultrasound scanning during this period can be assigned to women who carry twins or twins, triplets, as well as women who become pregnant due to IVF. If the expectant mother has complaints of poor health, pain, atypical discharge from the genitals for this trimester, she will also be recommended to undergo an ultrasound scan.
Those pregnant women who have undergone the treatment prescribed by the doctor are also subject to ultrasound examination so that the condition of the baby and the effectiveness of therapy can be assessed. The lag in the growth rate of the uterine bottom height, which is measured at each scheduled appointment in the obstetrician-gynecologist's office, can also serve as a reason for issuing a referral for an unscheduled ultrasound scan to eliminate the risk of intrauterine fetal growth retardation, placental insufficiency.
Sometimes an ultrasound scan at this time is necessary to check the timing of pregnancy, to clarify the date of birth, because this week the paperwork for obtaining maternity leave begins and the doctor must be sure that there were no mistakes in determining the timing.
How is the research done?
At 30 weeks, there is no need for intravaginal ultrasound diagnostics, in which the device's sensor is inserted into the vagina. The view through the abdominal wall is not difficult even in obese women, therefore the study is carried out externally - transabdominal. There is no need to prepare for it. The woman had to drink water and fill the bladder only at the very beginning of pregnancy, now the fetal bladder is filled with a sufficient amount of amniotic fluid, which conducts ultrasound waves well, and the picture on the monitor is quite clear and understandable.
Colon filling, gases also can no longer affect the scan results, because the large uterus has pushed the intestinal loops into the background in the truest sense of the word.
If a woman at 30 weeks decides to visit 3D or 4D ultrasound, a very interesting sight awaits her. These procedures are carried out in the same way as the usual two-dimensional research; these innovative diagnostic methods have no specific features.
The only significant difference is the time it takes to complete the survey. Two-dimensional ultrasound will require no more than 10 minutes, while three-dimensional and four-dimensional examinations require from 40 minutes to an hour. For any type of ultrasound this week, it is worth bringing with you an exchange card, as well as a clean diaper and replacement shoes.
What will the ultrasound show?
On the monitor of the scanner, the expectant mother will be shown a fairly grown baby. The size of the fruit this week is impressive - the growth of the crumbs approached 40 cm, and the weight is within 1.5 kg. From the beginning of the third trimester, the baby is actively gaining subcutaneous fat, folds and wrinkles on his skin are gradually smoothed out, chubby hands, cheeks, dimples so dear to the mother's heart appear.
Small lungs from this week begin to produce surfactant - a substance necessary for the normal functioning of the respiratory system. It is the surfactant that will prevent the lungs from sticking together during exhalation, and its concentration is very important so that the baby, if born prematurely, can breathe.
The child's movements are no longer as active as in the second trimester, when the mother could observe them during the second screening ultrasound examination. The reason is crowdedness. A child who has grown noticeably becomes uncomfortable and cramped in the womb, he already seeks to take a fixed, compact and most comfortable position for himself.
Tumble and swim in the amniotic fluid the baby can no longer.
The baby's heart beats very clearly and rhythmically at 30 weeks. Mom will definitely be able to hear him, doctors provide pregnant women with such an opportunity. Heart rate is normal at this time - from 130 to 170 beats per minuteMoreover, boys, according to experienced obstetricians, have a slightly less heartbeat than girls, the difference is about 10 beats per minute.
The child has very well-developed facial muscles, so the baby on an ultrasound scan can grimace, yawn, squint, frown and smile. If she's lucky, Mom can get a picture with such a funny face. Vision continues to develop, the baby perfectly distinguishes between light and darkness, his hearing allows him to distinguish the voice of his mother from the voices of other people. The formation of the nervous system continues in the baby, new grooves and convolutions appear in the brain every day - the baby grows smarter by leaps and bounds.
In most boys, the testicles descend from the peritoneum into the scrotum, and if this has not happened yet, then there is still time. The child has formed all organs and systems, they work. The stomach digests the amniotic fluid, which the baby swallows, the intestine accumulates the original feces - meconium, the liver at this time begins to accumulate iron for the future so that the child does not have anemia after the umbilical cord connection with the mother stops and an independent existence begins.
The child has formed small nails on the fingers and toes, the skin ceases to be saturated red and begins to acquire a more familiar human shade.
On ultrasound, at this time, the mother will no longer be able to see her unborn child in full in full, since the view of the sensor does not allow getting such a large picture. But the doctor will be able to show individual parts of the baby's body with a fairly high definition.
Decoding and norms
The norms included in the tables, with which diagnosticians and expectant mothers are checked, may differ for different babies at this time. The fact is that at such a long time, the baby is already similar to its parents, it inherits growth and a predisposition to a certain body type, and therefore one child may have longer legs, while the other has an estimated weight ahead of the average values.
Fetometric measurements at this time give only an approximate picture of compliance with the gestational age, to a greater extent, fetometry doctors try to imagine proportionality of the addition of the baby.
As in the previous weeks, the fronto-occipital and biparietal head sizes, the length of the paired bones - the femur and humerus, the lower leg and the forearm are measured. In numerical terms, the diameter of the chest and the circumference of the head and abdomen are determined. The table of fetometric indicators at 29-30 weeks of gestation is as follows:
The position of the fetus in the uterine cavity, which is detected on this ultrasound, can persist until the very birth, because it is now quite difficult for a grown child to roll over, but it is still possible, so there is no need to worry about a breech or transverse presentation yet. The baby has about 10 more weeks to take the head position, which is considered optimal for the birth process.
If it doesn't, doctors a couple of weeks before giving birth, a decision will be made on the tactics of delivery. The amount of amniotic fluid at this time is 64-90 mm, there is a tendency to decrease their amount, because a place in the uterus is required for a growing child. The umbilical cord, with its normal development up to 30 weeks, has a zero degree of maturity, and after this period it becomes the first. The thickness of the "child's seat" at this time is normal - 29.6-30.4 mm.
An ultrasound scan allows you to see the entanglement of the umbilical cord, if any. The umbilical cord itself during normal pregnancy has three vessels. The blood flow in them at 30 weeks can already be measured during an ultrasound scan with a Doppler, vessels with different filling and blood flow intensity on the monitor will be painted in different colors.
With the help of an ultrasound scan, the doctor will be able to understand whether the child is receiving sufficient nutrition, whether he has enough oxygen, whether he has signs of hypoxia. Determination of gender from 30 weeks becomes difficult. A large baby “gathers” into a lump, tightens his legs, so it is impossible to see intimate places.
But if the baby shows off its external genitals, then there will be no doubt, they are already well enough developed, and the mother will be able to consider herself who should be born - a boy or a girl.
To notice any warning signs of possible premature birth, the doctor can examine the cervix of the pregnant woman using a vaginal probe to assess its size, the degree of closure of the cervical canal. At this time, it should not be ajar.
If the walls of the uterus are in good shape, and the condition of the cervix does not inspire confidence in the doctor, he can hospitalize the expectant mother in the department of pathology of pregnant women of her chosen family house, so that in a hospital try to prolong the pregnancy. The baby can already survive if premature birth occurs, but it is better if he waits for at least another 7 weeks.
Pictures
Two-dimensional ultrasound images allow you to see the profile of the baby, his arms, legs, but the traditional ultrasound, alas, does not give an opportunity to even approximately imagine what the baby will look like after birth. On 3D ultrasound, you can get more interesting pictures, looking at which both the expectant mother and the future dad will be able to easily understand who the child looks like.
At week 30, the pictures are quite clear, a little later on ultrasound it will be quite difficult to get a clear image, since the amount of amniotic fluid gradually decreases, respectively, visualization will deteriorate.
The photographs should be requested in electronic form on any data carrier, since paper "photos" crawling out of the ultrasound machine are fragile.
You can find out about what happens to mom and baby at 30 weeks of pregnancy from the following video.
