This document summarizes abnormal labor and dystocia. It defines difficult labor as abnormal slow progress and lists the main indications as prolonged latent phase, protraction disorders of the active phase, and arrest disorders of the active phase. It evaluates labor based on cervical dilation and fetal descent, using Friedman's curve as a guideline. It then describes the main types of abnormal labor patterns and dystocia, which can be due to abnormalities of power (uterine dysfunction), passage (pelvic abnormalities), or passenger (fetal malpositions and sizes).

1. Abnormal labor and Dystocia Dept. of Ob&Gyn, The first affiliated hospital He Ke

2. Definition Difficult labor or childbirth Abnormal slow progress of labor

3. Incidence The most common indication for primary cesarean section

4. Abnormal patterns Prolonged latent phase Protraction disorders (active phase) Arrest disorders (active phase) Precipitate labor disorders

5. Evaluation index Cervical dilation Descent of the fetal presentation

6. Friedman’s curve

7. Latent phase Active phase I II stage 产程图 partogram

8. Prolonged latent phase 􀁺 Nulliparas Multiparas prolonged >20 hr > 14 hr Normal average 6.4 hr 4.8 hr

9. Protraction disorders 􀁺 Nulliparas Multiparas Descent <1.0 cm/h <2.0 cm/h Dilation <1.2 cm/h <1.5 cm/h Average 8hr 5hr

10. Arrest disorder 􀁺 Nulliparas Multiparas Descent >2h >1h Dilation >2h >1h

11. Partogram

12. A 潜伏期延长 prolonged latent phase B 活跃期延长 prolonged active phase C 活跃期停滞 arrest active phase Abnormal partogram

13. Partogram

14. Precipitate labor disorders 􀁺 Nulliparas Multiparas Descent >5cm/hr >10cm/hr Dilation >5cm/hr >10cm/hr

15. Classification of Dystocia Abnormalities of the Power Abnormalities of the Passage Abnormalities of the Passenger

16. Characteristics of the power Intensity is greater in the fundus Average 24mmHg Well synchronized Frequency Duration 60s regular Rhythm and force Basal resting pressure 12-15mmHg

17. Fetal monitoring

18. External and internal monitor

19. Uterine dysfunction Hypotonic Hypertonic Uncoordinated Inadequate expulsive efforts

20. Hypotonic dysfunction Insufficient Irregular Infrequent Response well to oxytocin Most in primigravidas in active phase

21. Hypotonic dysfunction etiology Malfunction Malpresentation Extrinsic factors

22. Hypertonic and uncoordinated dysfunction Resting tone Dyssynchronous Frequent intense contraction Constriction ring Tocolysis Decrease oxytocin Cesarean section Sedation

23. Pathological retraction ring

24. Constriction ring

27. Hypertonic Dysfunction

29. Inadequate expulsive efforts Second stage Assisted delivery might be needed Analgesic / anesthetic agents wear off

30. Abnormalities of the Passage Bony pelvic (most common) Soft tissue obstruction Abnormal placenta location

31. Bony pelvic abnormalities Inlet Midpelvic-outlet Generally contracted pelvic Deformed pelvic

32. Three level of bony pelvis

33. Contracted pelvis Contraction of pelvic inlet AP<10cm;transverse<12 cm Contraction of mid-pelvis interischial spinous diameter <10cm Contraction of pelvic outlet interischial tuberous diameter <8cm

34. Three anteroposterior diameters of the pelvic inlet

35. D iameter of the inlet and midpelvis

36. Fetopelvic disproportion

37. 正常骨盆 入口呈心型 出口呈漏斗型 funnel shaped pelvis 47.3% 5.8% 36.6% 10.9% gynecoid android Flat(platypelloid) anthropoid 前后径 狭 窄 横径 狭窄 transversely contracted pelvis 女性 男性

38. each pelvic plane is 2 cm less than normal 均小骨盆 generally contracted pelvis

39. osteomalacia oblique pelvis kyphosis 成人 行走之前 行走之后 Deformed pelvis

40. Soft tissue dystocia Congenital anomalies Scarring of birth canal Pelvic masses

41. Birth canal

42. Pelvic mass

43. Pelvic mass

44. Low –lying placenta

45. Abnormalities of the Passenger Malposition and malpresentation Fetal macrosomia Shoulder dystocia Fetal malformation

46. 13.3 9.5 11.3

48. ★ ★ Cepholic position and the diameter through pelvis occiput presentation parietal presentation brow presentation face presentation

49. Malpresentation

51. Breech presentation

52. Transverse fetal lie

53. Shoulder presentation

54. Examination

55. Fetal macrosomia large for gestational age(LGA) ≥4000g

56. Shoulder dystocia

58. Brachial Plexus Injury

59. Fetal malformation

60. Operative delivery 1)forceps operations

61. Operative delivery Vacuum

62. Operative delivery Cesarean Section

63. Reference Williams obstetrics (22nd edition) High risk pregnancy (2nd edition)