Contracted pelvis in Obstetrics

1. Contracted Pelvis. Fetal
Macrosomia
Lecture by Andriy Berbets

2. Measurement of the pelvis

3. Normal pelvis

4. Normal pelvis

5. Anatomically contracted pelvis
• The diagnosis is correct, if at least one
diameter is contracted 2cm +
• Classification:
- Generally contracted pelvis
- Simple flat pelvis
- Flat rachitic pelvis
- Transversely contracted pelvis

6. Anatomically contracted pelvis
Classification (by degree of contraction)
- 1st degree (conjugata vera 11-9 cm)
- 2nd degree (conjugata vera 9-7,5 cm)
- 3rd degree (conjugata vera 7,5-6,5 cm)
- 4th degree (conjugata vera less than 6,5 cm)

7. Generally contracted pelvis

8. Generally contracted pelvis

9. Generally contracted pelvis
• All the dimensions are equally contracted
(longitudinal and transverse)
• Delivery:
- over-flexion of the fetal head,
- passing of the fetal head through the pelvis on
oblique dimension,
- fetal head can’t fixate good enough to pubic
symphysis

10. Generally contracted pelvis

11. Generally contracted pelvis

12. Generally contracted pelvis

13. Generally contracted pelvis

14. Simple flat pelvis

15. Simple flat pelvis
•
•
•
•
All longitudinal dimensions are contracted
Internal rotation is problematic
Moderate extension of fetal head
Asynclitism

16. Asynclitism

17. Rachitic flat pelvis

18. Transversely contracted pelvis

19. Alternative classification

20. Alternative classification

21. Michaelis’ rhombus

22. Clinically contracted pelvis
•
•
•
-
Anatomical dimensions are normal
But fetus is too big and can’t pass through
Conditions for diagnosis:
Good regular uterine contractions
Cervical dilation 8cm +
Absence of amniotic sac
Empty urine bladder

23. Clinically contracted pelvis
•
-
Diagnosis:
No fetal head’s descending
Cervix is not closed to fetal head
High standing of contraction ring
Early pushing efforts (head is not in pelvic cavity)
Edema of cervix, vagina and vulva
Symptoms of urine bladder’s pressure
Positive signs of Vasten and Tsangemeister

24. Vasten’s sign

25. Threat of uterine rupture

26. Coxalgic pelvis

27. Ankilotic oblique-deformated pelvis

28. Pelvis due to osteomalatia

29. Scoliotic pelvis

30. Pelvis with no symphysis

31. Pelvis with no symphysis (“cleft”)

32. Osteoma

33. Shoulder dystocia

34. Shoulder dystocia

35. Thank you!