Obstetric ultrasound, also known as prenatal or pregnancy ultrasound, uses high-frequency sound waves to produce images of a developing embryo or fetus. The procedure also monitors the health of the mother's uterus, ovaries, and the blood flow through the umbilical cord to the placenta. Abnormal seems to imply that something is wrong with your baby,

1. Normal Obstetric Ultrasound

2. 1. Anatomy of fetal head on ultrasound

6. Normal value fetal structure :
1. Ventricle < 10 mm in diameter.
2. Pellucidum < 10 mm in diameter.
3. Choroid plexus : bright echogenicity.
4. D1 = D2 in diameter.

7. Common Fetal head pathology
Ventriculomegaly also called hydrocephalus > 10
mm in diameter.

10. SPALDING SIGN, fetal death.

11. Cephalocele

14. Spinal bifida

15. 2. Anatomy of the Fetal heart

17. Fetal Echocardiography
Scanning Technique
• 1st Step: Check the heart is beating
• 2nd Step: M-mode heart rate - should be between 120 and 180 beats per minute
• 3rd Step: Situs- check which is the left side of fetus then do a dual image in a tranverse axial plane
of the fetus with firstly the thorax showing the heart apex orientated to the left at an angle of
approximately 45degrees. The transverse section should only contain 1 rib. The second image
showing the stomach on the left ensuring the left and right side is labelled.
• 4th Step: Four Chamber View- Angling cephalad from a transverse axial view of the abdomen.
• The heart should occupy approximately 1/3 of the chest.The ventricles should be of similar size and
the atria should be of similar size. The moderator band is in the right ventricle. The left ventricle
extends more apically.
• Assess the AV valves (atrioventricular) ie The tricuspid valve on the right is more apical than the
mitral (on the left)valve insertion onto the interventricular septum. (the "offset cross" appearance)
• Watch ,in real time, the opening and closing of the valves in systole and diastole.
• The pulmonary venous connections can be identified.

18. 5th and 6th Step Outflow Tracts
• 5th Step: LVOT
• From the 4chamber view, angle further cephalad to see the Left ventricle and the aorta
(Left outflow tract) in the same view.
• The aorta will be coursing to the right posterior direction.It should be assessed in colour
Doppler also looking for any stenosis.
• 6th Step: RVOT From the LVOT view, the probe is angled further towards the head and
slightly towards the fetal left shoulder.
• This show the pulmonary trunk heading directly posteriorly towards the spine. It will
divide into the pulmonary arteries.
• Image and look in bmode and Colour Doppler.
• 7th Step: 3 Vessel View This view is a slightly oblique, axial view.
• It cuts the upper part of the arches and transversally the Superior Vena Cava.
This is an image with
1 A full length view of the Pulmonary Artery (P) which arises from the right ventricle.
2 A cross section of the ascending aorta (A)
3 The superior vena cava (V)

19. 8th steps: Interventricular Septum
• IVS (inter-ventricular Septum):
• Should be assessed when the foetus is in a decubitus position so the
ultrasound beam is perpendicular to the septum.
• This will avoid anisotropy and a false positve for septal defect.
• It should be assessed in both Bmode and Colour Doppler.
• 9th Step: Aortic Arch
• The 'arches' are best assessed when the foetus is prone.
• Aortic Arch: Turn the probe 90degrees to a para-sagittal plane on the
foetus.
• The Aortic arch arises from the centre of the heart and is commonly
referred to as a "cane".
• Coarctations may be visualised in this view.
• 10th Step: Ductal Arch

20. Common Fetal heart Pathology

22. • Ectopia Cordis

23. AV Septal Defect (Trisomy 21)

25. 3 Anatomy of the Fetal Abdomen
Ultrasound

26. Sonographic technique
Transverse section through the upper
abdomen, which should demonstrate the
following fetal landmarks:
1 fetal stomach
2 umbilical vein
3 portal sinus

27. Normal Umbilical cord insertion

29. Normal stomach and Liver position

30. Common Fetal Abdomen Pathology
Fetal Hydrops Fetalis ( pleural effusion, ascitis,
hydrocephalus): fetal dehydrate and tachycardia.

31. Double bubble sign, Duodenal atresia

32. Fetal bowel dilatation: small bowel>6 mm,
Colon>23 mm in diameter.

33. Fetal Hydronephrosis

34. Abdominal cyst formation

36. Gastroschisis: floating bowel without covered by
membrane. Both Gastroschisis and omphalocele
are unknown cause.

37. Omphalocele: like a mass covered by
membrane, bowel, stomach, spleen, bladder.

38. 4. Anatomy of the Fetal Bladder

40. It is generally defined as:
1. bladder diameter >7 mm in the first trimester
(1 – 13 weeks)
2. bladder diameter >30 mm in the second
trimester (14 -26 weeks)
3. bladder diameter >60 mm in the third
trimester (27 – 40 weeks)

41. Fetal Megacystis: enlarge fetal bladder.

42. Gender fetal : 14 – 16 weeks up
• Female: burger/Coffee bean sign
• Male

43. Baby girl about 20 weeks. Tri-line sign.

44. Thanks you so much