Ultrasound in pregnancy: the essence of the study and indications for its implementation
Ultrasound is a very informative modern diagnostic technique.The study is based on the analysis of the reflections of ultrahigh-frequency acoustic oscillations from tissues having different densities.Currently, ultrasound is used throughout pregnancy;It allows you to timely identify abnormalities of the future baby and take adequate measures.Table of contents: Do I need an ultrasound in pregnancy?Dangerous or not ultrasound in pregnancy?Ultrasound up to 10 weeks of ultrasound in 10-14 weeks of ultrasound in 14-20 weeks of ultrasound from 20 to 24 weeks of ultrasound at 32-34 week 3D-
Do I need an ultrasound in pregnancy?
The study refers to non-invasive, i.e., not accompanied by tissue damage.It is not associated with pain and other unpleasant sensations and does not have undesirable effects on the body of the future mother and fetus.Ultrasound enables the obstetrician-gynecologist to get a lot of valuable information - sometimes, vital for a woman and her unborn baby.
It is no exaggeration to say that this diagnostic procedure has saved the life and health of a huge number of mothers and their babies.Timely diagnosis of abnormalities in pre-natal development made it possible to avoid many complications.
The image obtained during the study allows us to consider:
- fetal position;
- is a multiple pregnancy;
- condition of fetal internal organs;
- is hypotrophy;
- pathology of intrauterine development of the child;
- polyhydramnios and hypodermis( abnormal volume of amniotic fluid);
- placenta previa.
Often, ultrasound can reveal the threat of miscarriage.Due to this, the patient is placed in a timely manner in a hospital under the constant supervision of doctors, thus saving the pregnancy.Identification of some pathologies facilitates the management of childbirth;In particular, ultrasonography can be established explicit indications for caesarean section.
Important: the need for ultrasonic scanning during pregnancy is documented by the RF Ministry of Health.
Is it dangerous or not an ultrasound in pregnancy?
According to a report presented by WHO( World Health Organization), this diagnostic technique does not harm the patient's health.The findings were made on the basis of data obtained during many years of research, which were conducted in leading world clinics.Reliably established that ultrasonic vibrations do not have a negative effect on the fetus.In vitro and in vivo studies( laboratory animals) have shown that the standard doses of high-frequency acoustic radiation do not adversely affect either the chromosomes of individual cells or the embryo as a whole.
Usual scanning takes 15-20 minutes, and to get a three-dimensional image of a future child it takes three times longer.Nevertheless, even 3D diagnostics are also recognized as safe.Without testimony to her, it is still not recommended to resort;It is not necessary to conduct ultrasound scores of times only in order to once again clarify, for example, the size of the fetus.
Note: in individual clinics where 4 D-ultrasounds are conducted, try to record whole films for the parents, exposing the woman and the fetus to the effects of acoustic waves for a very long time.Such records are of practical value only in individual cases, therefore, such procedures should be avoided or carried out as sparingly as possible.
Currently, ultrasound, which allows to assess the condition of the uterus and developing in her fetus, is carried out almost all pregnant women.The procedure is carried out at least three times( according to the recommendations of the WHO), if the pregnancy is conducted by a doctor from the earliest possible time.According to the indications, ultrasound can be performed more often.
During the study, the woman does not experience any discomfort;She senses only the movement across her stomach of the transducer sensor.
Ultrasound up to 10 weeks
Usually, for up to 10 weeks, ultrasound is needed to determine the very fact of pregnancy.Indication for the study is the delay of the monthly( if conception has not occurred, it is possible to identify pathologies).With a delay in menstruation and a positive result of a self-administered pregnancy test, ultrasound may not be absolutely necessary, but a negative result needs to be clarified, since "strips" are known to not give 100% accuracy.
Important: should note that such a serious pathology as an ectopic pregnancy is detected during ultrasound as early as the 12-14 day after fertilization of the oocyte.
There are a number of indications for conducting an ultrasound study for less than 10 weeks:
- pains in the lower abdomen;
- marked weakness and dizziness;
- bleeding from the genitals( regardless of intensity and color);
- pregnancy due to IVF and other ancillary medical technologies;
- Suspicion of an undeveloped pregnancy( death of an embryo without clinical signs of miscarriage);
- history of miscarriage( undeveloped pregnancy or spontaneous abortion that occurred before);
- abnormalities of fetal development during one of the preceding pregnancies;
- high probability of multiple pregnancies.
Important: The reason for suspicion of a non-developing pregnancy is the inconsistency of the probable period of pregnancy established for palpation of the size of the uterus.The probability of multiple pregnancies is great in IVF, if several fertilized eggs are inserted into the uterus at once.Double and triplets are possible if in preparation for conception a woman received special hormones.
Ultrasound in 10-14 weeks
The first planned ultrasound is recommended to be completed in 10-14 weeks.At earlier times, the diagnostic procedure in the absence is relatively infrequent in connection with relatively low informativeness.
Carrying out ultrasound in the first trimester is absolutely necessary, as it allows to determine deviations that are incompatible with life or will inevitably cause severe disability of the baby.The disappointing results obtained during the study, become an unconditional basis for the use of invasive techniques - the analysis of amniotic fluid and chorion biopsy( placenta).When confirming the presence of severe pathology, the question of urgent artificial termination of pregnancy is raised.
Important : First trimester abortion is much less dangerous for a woman than artificial delivery at a later date.
There are a number of indicators that are of interest only for early-stage studies.
For example, at 11-14 weeks, ultrasound can set the size of the so-called.Cervical collar space.
Until the 15th week, ultrasound can provide a high degree of accuracy in determining the length of the fetus.Later this indicator is not very informative, since the genetic( hereditary) factors already influence the size( growth).
Ultrasound at 14-20 weeks
The procedure is not planned on this date.It is indicated if the tests indicate a change in the normal hormone level for pregnancy.
Ultrasound from week 20 to 24
The second scheduled diagnosis by ultrasound is carried out at 20-24 weeks.
Important: in 22-24 weeks of ultrasound allows you to set the gender of the baby.Sometimes, you will have a boy or a girl, you can still in the first trimester.If you do not want to know the sex of the child before birth - in advance, warn the diagnostician!
The main task of ultrasound diagnostics in the second trimester is also the timely detection of anomalies in intrauterine development.At this stage of fetal development, it becomes possible to identify many pathologies of internal organs.
It is very important to assess the size of the placenta and establish the presence of cystic neoplasms and calcium deposits in it.It is through the placenta that the mother's organism interacts with the fetus, providing it with substances, vitamins and vital microelements that are necessary for growth and development.
The study determines the volume of the amniotic fluid.The mismatch of amniotic fluid volume to normal indices often indicates an unfavorable course of pregnancy, and is an indication for a more in-depth examination.Conclusions made on the basis of ultrasound data will allow to make corrections to further medical tactics.
From 20 to 24 weeks, this type of ultrasound diagnosis, such as Doppler.The technique allows to study the state of the blood vessels of the uterus, placenta and umbilical cord.Through the "Doppler study" a specialist can reveal the slightest violations of uteroplacental blood flow and predict the further course of pregnancy, taking into account their severity.On the one hand, this technique can be considered as an additional one, but on the other hand, only a combination of "ordinary" ultrasound and Doppler ultrasound gives the possibility to assess the fetal condition objectively and to reveal the possible presence of blood circulation pathologies.
Ultrasound for 32-34 weeks
At this time it's time to undergo a third planned examination using an ultrasound scanner.
Note: from 24 to 32 week of ultrasound is carried out only if there are indications
The time interval between Doppler is usually not less than 1 month, since within a shorter period of diagnostic significant changes in blood circulation do not develop( even in the worst case theyGrow gradually).However, for example, with a change in the coagulability of the blood, the attending physician can prescribe a study of the blood flow status before the prescribed time.In the event that the violations are confirmed, appropriate treatment is prescribed, which is necessary, in particular to prevent gestosis( late toxicosis).After it, additional ultrasound and dopplerography are mandatory.If the therapy did not give the desired results, the course is repeated, after which the control ultrasound is again performed.
Thus, the total number of ultrasound studies in the third trimester directly depends on the presence of pregnancy pathologies and the effectiveness of ongoing course treatment.
If the doctor in question has any doubts about the accuracy of standard ultrasound and especially when serious abnormalities are detected, the woman is referred to specialized centers for second level scanning.In perinatal centers, high-precision obstetric screening is carried out by specialists using equipment that is characterized by the highest possible resolution.
Although the most significant malformations are usually detected earlier, at the 32-34 week the issue of detecting possible anomalies is not becoming less relevant.In particular, it is at later periods that a mega-uriter( pathological enlargement of the ureter in a future child) and hydronephrosis( the presence of fluid in the renal pelvis) are more often diagnosed.Impossibility of earlier detection of a number of pathologies can be caused by inconvenient for scanning the position of the fetus in the uterine cavity.
If significant abnormalities are detected, the question may be raised about early( before 40 weeks) medical abortion or child-to-child operation as soon as it is born.
Modern medical technologies allow prenatal operations and some less radical interventions to save lives or preserve a baby's health before his birth.In particular, if there is a violation of urinary retention due to an abnormality of the urethra, a puncture of the bladder of the fetus is performed under the control of the ultrasound apparatus.It makes it possible to prevent the destruction of kidney kidney.
The most important tasks of ultrasound at 32-34 week:
- evaluation of fetal dimensions( identification of possible developmental delays);
- assessment of blood flow in the umbilical cord, placenta and uterus;
- establishing the location of the fetus in the uterus( headache or pelvic presentation, etc.);
- revealing a possible presentation of the placenta( the question of the need for caesarean section is being solved).
Important : Fetal embedding can rarely change( up to a 180 ° turn) even after 34 weeks of gestation, therefore midwives can not always rely on ultrasound data from earlier time periods.In some cases, an additional ultrasound examination is already performed immediately before delivery.It is indicated to pregnant women suffering from excess weight, for additional clarification of the presentation of the child.Ultrasound before delivery allows obstetricians to choose the optimal method of delivery - natural or through surgical intervention.
The technique that allows to obtain a three-dimensional image of an unborn child is additional.An experienced specialist can detect anomalies in the development and in the course of "normal" ultrasound.In the 3D-picture, you can only look at the external appearance of the fetus, and the state of its organs and systems can not be estimated.In rare cases, it is the three-dimensional picture that allows to identify such anomalies as the "hare's lip"( splitting of the lips rather than the sky) or polydactyly( anatomical deviation, with more than 5 fingers on the limb).
3D-ultrasound is more interesting for parents, because it gets the opportunity to receive and save on a digital medium an image close to a digital photograph.The same applies to 4D, and to examine the facial expressions and movements of the mother's future child, a study of up to 1 hour or more is required.
The changes in the placenta state revealed during ultrasound often allow for timely and adequate treatment.This avoids the birth of a child before the term or with low weight.
Viktorova Julia, obstetrician-gynecologist