It's the ultrasound study useful for the diagnosis of uterus pregnancy under developmental, to perform a correct dating of pregnancy, to search for early signs of anatomical abnormalities and for the evaluation of indicators (markers) of chromosomal disorder, including the measurement of nuchal translucency (NT).
WHEN IS THE APPROPRIATE TIME TO PERFORM THE EXAMINATION?
The best time to perform the ultrasound examination is between 11 weeks and 13 weeks and 6 days of pregnancy.
WHAT IS A NUCHAL TRANSLUCENCY (NT)?
The nuchal translucency is the thickness found behind the neck of the fetus. It is measured on the median sagittal view of the fetus. This thickness is considered within normal limits, when it is less than 3 mm.
If the nuchal translucency ultrasound shows that it is greater than 3 mm then this condition may involve: malformation syndromes, cardiac or other organ abnormalities, chromosomal abnormalities (i.e., the Down Syndrome, or other more rare diseases).
WHAT IS WHAT IS A SECOND TRIMESTER MORPHOLOGY ULTRASOUND?
It's an ultrasound examination, which requires a good deal of experience, in which it's performed a detailed evaluation of biometrics, and the anatomy of the fetus. The main purpose of this examination is to exclude fetal malformations, which requires about an hour. It also performs a flow meter utero-placental study, searching for any abnormalities, predisposing the fetal to growth retardation and the development of gestational hypertension.
The fetal ultrasound examination may be supplemented by measuring trans-vaginal cervix, to identify women at risk of of preterm birth (cervicometry).
WHAT ANATOMICAL QUALITIES ARE EVALUATED DURING THE MORPHOLOGY ULTRASOUND?
Nel corso dell'esame ecografico devono essere valutate le seguenti strutture:
Skull: evaluation of a normal conformation.
Brain: technique with multiplanar display of the cerebral hemispheres, extracerebral CSF spaces, the lateral ventricles, third and fourth, of the corpus callosum and the cavum pellucidum, and the hemispheres of the cerebellar vermis, the first brain grooves (insula, parietal-occipital sulcus) and evaluation of a normal development for its time.
Face: evaluation of orbits, glassy bodies, nose, lips, palate and anterior mandible.
Spine: with neural tube apparently intact.
Chest: lungs with homogeneous echogenicity, normopositioned mediastinum .
Heart: evaluation of situs, levocardia, atrioventricular and ventricular-arterial connections, inferior vena cava, transverse aortic arch (normal caliber and to the left of the trachea); the color / pulsed Doppler shows normal flows through the atrioventricular and semilunar valves, cardiac function, the pace and frequency.
Abdomen: assessing the integrity of the anterior wall.
Gastrointestinal tract: display of the stomach, usually in the supine position.
Kidney / Bladder: the presence of normal sized kidneys, morphology and echogenicity, renal pelvis and bladder usually in the supine position. Limbs: presence and regularity of three segments of each limb.
WHEN IS THE BEST TIME TO PERFORM A MORPHOLOGY ULTRASOUND?
The best time to perform the ultrasound examination is between 19 weeks and 21 weeks of pregnancy.
WHAT ARE THE LIMITS OF A MORPHOLOGY ULTRASOUND?
The accuracy of the examination is not absolute. And only detailed diagnosis allows you to recognize the vast majority of malformations, although not all, probably on the order of 80%. A failed diagnosis can be the consequence of the physical limit in current technology (small flaws, such as cardiac septal defects, or anomalies of the fingers, and especially phalanges, for example, cannot be proven, as well as defects not revealed by ultrasound, such as the isolated cleft palate) or of the general history of the anomaly (some defects, such as abnormalities of the cerebral convolutions, some skeletal dysplasias, intestinal obstructions, certain dysfunctions of the urinary tract) may develop or otherwise clearly manifest themselves only during pregnancy or after the child’s birth. Sometimes the accuracy of ultrasound morphology may be lessened due to certain conditions such as a large thickness of the maternal abdominal wall, lack of amniotic fluid, an unfavorable position of the fetus, twins, rendering the display less than optimal.
WHAT IS THIRD TRIMESTER ULTRASOUND?
It’s an ultrasound examination in which we consider the growth of the fetus and a complete anatomical study to rule out any developmental disorders that cannot be diagnosed using ultrasound morphology. It also studies the umbilical velocimetry to detect any growth retardation.
WHEN IS THE BEST TIME TO PERFORM A THIRD TRIMESTER ULTRASOUND?
The best period to perform the examination is between 30 and 34 weeks of pregnancy.
WHAT ARE THE NORMAL BIOMETRIC VALUES?
The fetus is defined by its normal size when its weight is placed between the 10th and 95th percentile in the growth curves.
WHEN ARE THE BIOMETRIC INDICES ALTERED?
If the weight falls below the 10th percentile, the fetus is considered small for its gestational age, then we speak instead about fetal growth restriction if the weight falls below the 5th percentile. When, however, the fetal weight appears to be above the 95th percentile, then we speak about fetal macrosomy. Both of these conditions, although at the antipodes, require intensive ultrasound monitoring of the fetus and are often associated with systemic diseases such as maternal hypertension, pre-clampsia, gestational diabetes, chromosomal abnormalities, and other related syndromes.
WHAT ARE THE LIMITS OF THE THIRD TRIMESTER ULTRASOUND?
The accuracy of the examination can be often reduced because of the position of the fetus as its size, by now substantial, greatly reduces the ability of movement; between the conditions that reduce the accuracy of the examination for poor visibility; there is also an increased thickness of the maternal abdominal wall, the scarcity of amniotic fluid, and the presence of twins.
HOW TO RESERVE AN OBSTETRIC ULTRASOUND?
The ultrasound examinations to patients from San Marino are reserved at the same time of the routine obstetric checkups. The non-assisted patients, who would like to undergo an obstetric ultrasound, may instead call us at 0549 994506 from Monday to Saturday from 8 am to 5 pm and fix an appointment with one of our professional specialists.