In accordance with the the Polish Gynaecological Society guidelines the current standard procedure is to perform three obligatory scans during pregnancy
- Genetic first trimester ultrasound – with a computer analysis of fetal genetic disorders development risk
- Genetic second trimester ultrasound – with a three-dimensional view 3D/4D scan
- Third trimester ultrasound – assessment of development and well-being of the fetus
Genetic first trimester ultrasound
This is the 11-13+6 weeks scan (MA + NT + NB + others).
- we analyse uterus structure (presence of uterine fibroids), uterine length and utterine appendages (pathological changes).
- we estimate the number of gestational sacs located in the uterine cavity.
- analysis of the structure of the embryo:
- chorion placement,
- amount of liquor amnii,
- FHR – fetal heart rate.
- analysis of fetal anatomy
- fetal biometry:
- BPD – biparietal diameter
- CRL – crown rump length,
- skull: midline echo, symmetry of lateral ventricles, choroid plexus,
- integrity of abdominal wall (ruling out hernias),
- chest: lungs and four heart chambers,
- abdominal cavity: stomach, liver, kidneys, fetal urinary bladder,
- spine,
- detailed analysis of Down syndrome markers:
- NT – nuchal translucency,
- NB - nasal bone.
- fetal biometry:
Genetic second trimester ultrasound
The scan is performed between the 18th and the 22nd week of pregnancy.
- Fetal biometry
- BPD – biparietal diameter,
- HC – head circumference,
- AC – abdominal circumference,
- FL – femur length.
- We check the heart rate and and some other details of heart work (FHR)
- At this stage the fetus is big enough for fetal anatomy to be closely observed:
- fetal skull: midline echo, symmetry of lateral ventricles, choroid plexus, cerebellum, posterior cranial fossa,
- viscerocranium: facial profile, nasal bone, orbits, integrity of the upper lip
- spine: we evaluate its integrity in cross-section and longitudinal section in order to rule out hernias,
- abdominal cavity: integrity of abdominal wall, stomach, liver, gallbladder, umbilical vein, kidneys, echogenicity of the fetal bowel, urinary bladder,
- limbs (bone length, number of fingers, foot anatomy),
- structure and placement of placenta, grading of placental maturity according to Grannum classification,
- analysis of umbilical cord (number of vessels),
- measurement of the amniotic fluid index (AFI).
A careful analysis of markers for Down syndrome and other syndromes is of utmost importance. It is understood that an underdeveloped nasal bone may be a clear predictor of an increased risk of the chromosomal birth defect. We measure NB (nasal bone length), NF (nuchal fold thickness). To rule out intraventricular extension or hydrocephalus we measure the width of the fetal lateral ventricular atrium.
Three-dimensional 3D/4D ultrasound.
NIt is recommended that the scan takes place between the 20th and 24th week of pregnancy. 3D/4D ultrasound allows to see the baby in three-dimensional view in real time. We can observe the baby’s physical appearance: face, torso, limbs as well as establish their sex. An important aspect of the viscerocranium scan is the assessment of facial features with the help of 3D technology. It allows to identify or rule out some of the congenital disorders (e.g. cleft upper lip). The effectiveness of this scan is dependent on the stage of fetal development, fetal position, the amount and density of amniotic fluid, and the depth of penetration of ultrasound waves through the adipose tissue of the abdominal wall of a pregnant woman. .
Third trimester ultrasound
It is recommended that the scan takes place between the 28th and 32th week of pregnancy.
Continuation of fetal biometric check-up. Assessment of anatomy, development and well-being of the baby (amount of amniotic fluid, placental maturity)