Intrapartum sonography can be used to more accurately assess fetal head position, station, descent, and rotation during labor compared to digital examination alone. It also helps predict success of induction of labor and instrumental delivery. The document outlines the basic technique, objectives, and various clinical applications of intrapartum sonography during different stages of labor.

1. Role of Ultrasonography in
Labour Ward
Dr/ Mahmoud Abdel-Aleem
Assistant Professor of Obstetrics and
Gynecology

3. INTRODUCTION

4. • Extensive evidence over the last 30 years has
demonstrated the value of ultrasound in the
prenatal fetal assessment (anatomy, physiology
and pathology): Antepartum Sonography
• Over the last 10 years, recent studies suggest that
ultrasound may play an important role in the
prediction of the time of onset and the progress
of labor: Intrapartum Sonography (IPS)

5. What do we need to learn?
• Is it the emergency obstetric care unit ?
• Is it the labour ward?
• Is it the delivery room?

6. BASICS OF INTRAPARTUM SONOGRAPHY

7. • Machine: simple 2-D machine can be used
satisfactorily
• Probe: abdominal probe with a frequency 3.5-
5.5 MHz
• Route:
– Abdominal.
– Trans-perineal (translabial).

8. TECHNIQUE OF IPS

9. Intrapartum
Sonography
TRANS-ABDOMINAL
Position Engagement
TRANS-PERINEAL
Position Progress Prediction

10. A- Transabdominal IPS

11. Technique
• Maternal position: supine
• Transducer position: transverse on the
suprapubic region of the maternal abdomen
• Landmarks:
– The foetal orbits.
– Midline cerebral echo.
– Cerebellum.

12. B- Trans-labial (TRANS-PERINEAL) US

13. Technique
• Position: supine
• Transducer: place a covered transabdominal transducer
on the perineum in a mid-sagittal position between the
labia below the pubic symphysis.
• Manipulate the probe by small lateral movements until
an image is obtained that visualizes clearly symphysis
pubis and fetal skull with no shadows from pubic rami.
• Landmarks:
– The foetal orbits: occipto-posterior
– Midline cerebral echo: occipto-transverse.
– Cerebellum: occipto-anterior

14. OBJECTIVE VALUE OF IPS

15. Three Practical measures that are
measurable and reproducible !!
1. Progression distance:.
2. Fetal head direction:
3. Angle of progression:

16. I. Progression Distance
Distance from the lowest part of the fetal skull related to a line
perpendicular to the inferior border of the symphysis pubis

17. II. Fetal Head Direction
Assesses the direction of the fetal head related to same
line

18. Downward
direction

19. Horizontal direction

20. Upward Direction

21. III. ANGLE OF PROGRESSION
Assesses the angle between the pubic symphysis
and a line tangential to the skull contour.

22. Angle of progression

23. SOME IMAGES

29. INDICATIONS OF IPS

30. WHEN TO USE IPS ?
INDUCTION OF
LABOUR
PRELABOUR
LABOUR:
FIRST STAGE
PROGRESS
LABOUR:
SECOND STAGE
NORMAL
INSTRUMENTAL
LABOUR:
THIRD STAGE

31. I- IPS before Induction of Labour
• Four sonographic parameters predicts success
of induction:
– Pre-induction cervical length. <20 mm
– Position of the fetal occiput.
– Posterior cervical angle. < 90
– Perineum-head distance. <40 mm
The odds of CS increases by about 10% with each
increase of 1 mm in cervical length above 20 mm

33. Head-Perineum Distance
• Shortest distance
between the outer
limit of the fetal skull
and the perineum
(transverse view).

34. • Adopting a policy of “delayed induction” in
prolonged pregnancy: Rao et al, 2008
– 80% spontaneous onset of labour and delivery.
– 50% reduction in fetal distress.
– 50% reduction in failure to progress.
– 50% reduction in the need for prostaglandin (Park et al.,
2011)
Ultrasound-based Prolonged
Pregnancy clinic

35. WHEN TO USE IPS ?
INDUCTION OF
LABOUR
PRELABOUR
LABOUR:
FIRST STAGE
PROGRESS
LABOUR:
SECOND STAGE
NORMAL
INSTRUMENTAL
LABOUR:
THIRD STAGE

36. II- Pre-labour
• To differentiate false from true labour pains.
• They evaluated 100 with a diagnosis of labor.
• To determine if the presence or absence of fetal breathing
movements was helpful in diagnosing false from true labor.
• Results:
– 30/31 (96.8%): of patients with absent FBM delivered within 48 hours.
– 61/69 (88.5%): of patients with preserved FBM continued pregnancy
for at least 48 hours.
– There is no difference in its use between term and preterm babies.
Boylan P, O'Donovan P, Owens OJ. Obstet Gynecol. 1985
Oct;66(4):517-20

37. An EBM!
• A SR (8 studies, 328 patients), evaluating the
accuracy of absence of FBM in predicting
spontaneous preterm birth in women with
threatened preterm labor.
• Absence of fetal breathing movements is a
useful test in predicting preterm birth both
within 7 days and within 48 h of testing.
H. HONEST*, L. M. BACHMANN*†, R. SENGUPTA*, J. K. GUPTA*, J. KLEIJNEN‡ and K. S. KHAN*.
Accuracy of absence of fetal breathing movements in predicting preterm birth: a systematic
review. Ultrasound Obstet Gynecol 2004; 24: 94–100

38. WHEN TO USE IPS ?
INDUCTION OF
LABOUR
PRELABOUR
LABOUR:
FIRST STAGE
PROGRESS
LABOUR:
SECOND STAGE
NORMAL
INSTRUMENTAL
LABOUR:
THIRD STAGE

39. III. First stage
Question I: Why did obstetrician think of using
US to follow the progress of labour during first
stage of labour ??
Question II: How shall we use IPS?
To assess head position.
To assess head station.
To assess head rotation.

40. The story of digital pelvic examination
• HEAD POSITION:
– It is not accurate for the determination of fetal
head position during labor. Discrepancy reaches
53 and 39% of patients in the first and second
stage of labor Sherer et al., 2002.
– Failed to diagnose fetal head position in 34% of
cases, and incorrectly determined head position in
51% of patients. Akmal et al., 2002.

41. Another trial !!
• HEAD POSITION:
– Was not possible in 61% of cases in the first stage and
in 31% in the second stage of labor.
– Was inaccurate in 69% of the cases in the first stage
and in 34% of cases in the second stage of labor.
– Difficulty was more likely if the occiput was posterior
in comparison to anterior and in the maternal right in
comparison to the left side.
Souka et al., 2003

42. A Third Trial !!!
• HEAD STATION: Dupuis et al, 2005
– Incorrect assessment: 50-88% of cases for residents
and in 36–80% of cases for obstetricians.
– The commonest mistake: misdiagnosis of a station
as representing a mid-pelvic station rather than a
true high-pelvic station accounted for 88 and 67%
of the errors made by residents and obstetricians,
respectively.

43. A recent trial; April 2013
• Aim: to analyze the relationship between IPS parameters
and to compare them with digital palpation.
• Methods: university hospital in Norway, comparing 3-D
transperineal IPS to digitally palpated head station and
cervical dilatation.
• Conclusion: IPS shows high degree of correlation with
each other, but only moderate correlation to vaginally
palpated fetal head station.
Tutschek, B., Torkildsen, E.A., Eggebø, T.M. 2013. Comparison
between ultrasound parameters and clinical examination to
assess fetal head station in labor. Ultrasound in Obstetrics and
Gynecology 41 (4) , pp. 425-429.

44. On The Other Hand

45. There is a good correlation between gold standard (MRI) and perineal US with
subsequent proposed clinical benefit, Bamberg 2012

46. Assessing Head descent
• The angle of head descent measured by
transperineal sonography is an objective,
accurate and reproducible means for assessing
descent of the fetal head during labor.
A. F. BARBERA, X. POMBAR, G. PERUGINO, D. C. LEZOTTE§ and J. C.
HOBBINS 2009. A new method to assess fetal head descent in labor with
transperineal ultrasound Ultrasound Obstet Gynecol 2009; 33: 313–319

47. Assessing Head Position
• Aim to determine whether US is more accurate than vaginal
examination in the determination of fetal occiput position in
the second stage of labor.
• Study design: 88 patients were evaluated by vaginal
examination and by combined transabdominal and
transperineal ultrasound examination to determine occiput
position.
• Results: Vaginal examination was correct in 71.6% of the time;
ultrasound was correct in 92.0% of the time (P=.018).
Margaret R. Chou, Doron Kreiser, M. Mark Taslimi, Maurice L. Druzin, Yasser
Y. El-Sayed,. Vaginal versus ultrasound examination of fetal occiput position
during the second stage of labor American Journal of Obstetrics and
Gynecology (2004) 191, 521e4

48. Assessing head engagement
• There is high rate of agreement (85.6%)
between IPS and digital assessment of fetal
head engagement.
• These data support the use of intrapartum
trans abdominal assessment of fetal head
engagement.
D. M. SHERER and O. ABULAFIA. Intrapartum assessment of fetal head
engagement: comparison between transvaginal digital and transabdominal
ultrasound determinations. Ultrasound Obstet Gynecol 2003; 21: 430–436

49. Assessment of Head Rotation

50. Assessing Head Moulding

51. WHEN TO USE IPS ?
INDUCTION OF
LABOUR
PRELABOUR
LABOUR:
FIRST STAGE
PROGRESS
LABOUR:
SECOND STAGE
NORMAL
INSTRUMENTAL
LABOUR:
THIRD STAGE

52. IPS before ventouse application
Transabdominal IPS assessment of the fetal head
position during the 2nd stage of labor improves
the accuracy of vacuum cup placement.
G.Y. Wong a, Y.M. Mok a, S.F. Wong. Trans-abdominal ultrasound
assessment of the fetal head and the accuracy of vacuum cup
application International Journal of Gynecology and Obstetrics (2007)
98, 120–123

53. Prediction of success of ventouse
delivery
• Good prognostic signs:
– Head-up sign (head pointing ventrally)
– Objective descent of the fetal head below infrapubic
line, both noted at the height of pushing.
• The ‘infrapubic line’: perpendicular to the long axis of the pubic joint
and extending dorsally from its inferior margin in a mid-sagittal plane
• The widest fetal head diameter and its movement with regard to the
infrapubic line during pushing.
• The ‘head direction’.
Henrich W, Dudenhausen J, Fuchs I, Kamena A, Tutschek B: Intrapartum
translabial ultrasound (ITU): sonographic landmarks and correlation with
successful vacuum extraction. Ultrasound Obstet Gynecol 2006; 28: 753–760.

54. WHEN TO USE IPS ?
INDUCTION OF
LABOUR
PRELABOUR
LABOUR:
FIRST STAGE
PROGRESS
LABOUR:
SECOND STAGE
NORMAL
INSTRUMENTAL
LABOUR:
THIRD STAGE
Retained
Placenta

55. Retroplacental Myometrium
Role of nitric oxide
Resting time Latent Phase Contraction/detachment

57. Placenta not delivered 30 minutes
1- Edge of the placenta is palpable through tight cervical os
2- Fundus small and contracted.
US: the myometrium is seen to be thickened all around the
uterus and a clear demarcation is often seen between the
placenta and the myometrium
Trapped
placenta
Tocolytics
“Nitrolgycerin”
Succeeded Failed
MROP
With no bleeding
US. Myometrium will be thickened in all
areas except where the placenta is
attached where it will be very thin or
even invisible
Adherent
placenta
Systemic
oxytocics
FailedSucceeded
Intraumbilical
oxytocics
Succeeded

58. Pipingas technique

59. 10 FAQ (FREQUENTLY ASKED QUESTIONS)
ABOUT IPS

60. Is it important to learn IPS?
Ultrasound in Obstetrics & Gynecology
Volume 41, Issue 4, pages 361–363, April
2013
ACOG releases a DVD in 2004 for standards
in performing IPS
There are ongoing multicetre RCTs to evaluate
its role in intrapartum care
LAST 2 ISOUG conference had much
discussion about IPS

61. Is it easy to learn IP sonography?
• Learning and accuracy of the determination of
fetal head position in labor is easier and
higher, respectively, with trans-abdominal
sonography than with digital examination.
• This should encourage physicians to introduce
clinical ultrasound examination into their
practice.
P. ROZENBERG, R. PORCHER, L. J. SALOMON, F. BOIROT, C. MORIN and Y. VILLE. Comparison of the
learning curves of digital examination and transabdominal sonography for the determination of
fetal head position during labor. Ultrasound Obstet Gynecol 2008; 31: 332–337

62. Does IPS needs special experience?
• No:: Measurement of the angle of progression
on transperineal ultrasound imaging is reliable
regardless of fetal head station or the
clinician’s level of ultrasound experience.
A. M. DU¨ CKELMANN, C. BAMBERG, S. A. M. MICHAELIS, J. LANGE, A. NONNENMACHER, J. W.
DUDENHAUSEN and K. D. KALACHE. 2010. Measurement of fetal head descent using the ‘angle of
progression’ on transperineal ultrasound imaging is reliable regardless of fetal head station or
ultrasound expertise. Ultrasound Obstet Gynecol; 35: 216–222

63. Is it convenient to the patient?
• Yes: it takes < 5minutes to perform.
• Yes: it is even more tolerable than digital
examination

64. Is 3D superior to 2 D in IPS?
• NO
– For single ultrasound operator the intraobserver
repeatability and agreement between 2D and 3D
ultrasound methods in prolonged first stage of labor
were good.
– Because 2D methods are simpler to learn and can be
analyzed quickly, 2D equipment are therefore preferred
in the labor room.
E. A. TORKILDSEN, K. A° . SALVESEN and T. M. EGGEBØ. Agreement between two- and
three-dimensional transperineal ultrasound methods in assessing fetal head descent in
the first stage of labor. Ultrasound Obstet Gynecol 2012; 39: 310–315

65. Does IP US have predictive clinical
value?
Yes
• Favorable for vaginal delivery:
– Fetal head–perineum distance: < 40mm
– Angle of progression: > 110 ͦ
• 2D or 3D ultrasound have similar predictive
values.
E. A. TORKILDSEN, K. A° . SALVESEN and T. M. EGGEB. Prediction of delivery mode with
transperineal ultrasound in women with prolonged first stage of labor. Ultrasound
Obstet Gynecol 2011; 37: 702–708

66. Does IP US have predictive clinical
value?
• When the angle of
progression was 120◦,
the probability of
either spontaneous
vaginal delivery or an
easy and successful
vacuum extraction
was 90%.
K. D. KALACHE, A. M. DU¨ CKELMANN, S. A. M. MICHAELIS, J. LANGE, G. CICHON and J. W. DUDENHAUSEN.
Transperineal ultrasound imaging in prolonged second stage of labor with occipitoanterior presenting fetuses:
how well does the ‘angle of progression’ predict the mode of delivery?. Ultrasound Obstet Gynecol 2009; 33:
326–330

67. Does IP US have predictive clinical
value?
• The shorter the head-
to-perineum distance,
the shorter the time to
deliver.

68. Can it lower CS rate?
• Yes by more objective use of intsrumental
delivery.
• Yes by better assessment of progress of labour
• Yes by lowering the need for induction of labour

69. Does it replace clinical examination?
No
• It just tunes finely the clinical examination
(improves its value).
• It is superior in difficult cases.

70. RESEARCH AGENDA

71. We have the patients, man power, US
machines !!!!
• RCT addressing the value of “ultrasound-
based prolonged pregnancy clinic”
• RCT addressing the issue of lower CS rate
through more liberal use of IPS.
• RCT addressing its value before ventouse
application.

72. TAKE HOME MESSAGE

73. 1. IPS adds significant importance to the conduct of normal
labour and instrumental delivery.
2. IPS is essential but not substitute to clinical skills.
3. The best predictor for success of induction is cervical length
measured by US.
4. The best predictor for vaginal delivery is angle of progression.
5. Our emergency unit is a rich source for applying useful
research beneficial to science and to our patients.
6. IPS may decrease the need for CS; it may represent a trial to
overlook the sarcastic dictum “Once a pregnancy, always a
cesarean !!”