This document outlines intrapartum care and management of abnormal labor, detailing the stages of labor, evaluation of complications, and methods of delivery. It emphasizes the importance of monitoring fetal and maternal conditions to detect abnormalities early and ensure optimal outcomes. Key terminology and assessment strategies are provided, alongside indications for interventions like oxytocin administration and potential management pathways for various labor dysfunctions.

1. Intrapartum Care & Abnormal Labor Francis S. Nuthalapaty, MD Medical Student Lecture Series Department of Obstetrics & Gynecology Greenville Hospital System University Medical Center Greenville, South Carolina

2. Learning Objectives APGO ET-11: Intrapartum Care Understanding the process of normal labor and delivery allows optimal care and reassurance for the parturient and timely recognition of abnormal events. APGO Medical Student Educational Objectives 8 th Ed. 2004

3. Learning Objectives ET-11 APGO Medical Student Educational Objectives 8 th Ed. 2004 KH Describe the evaluation of common puerperal complications KH Describe the different methods of delivery with the indications and contraindications of each SH Describe the steps of a vaginal delivery KH Describe the three stages of labor and recognize common abnormalities KH List the signs and symptoms of labor Level of Competence Objective

4. Learning Objectives APGO Educational Topic 22: Abnormal Labor Labor is expected to progress in an orderly and predictable manner. Careful observation of the mother and fetus during labor will allow early detection of abnormalities so that management can be directed to optimize outcome. APGO Medical Student Educational Objectives 8 th Ed. 2004

5. Learning Objectives ET-22 APGO Medical Student Educational Objectives 8 th Ed. 2004 K List indications and contraindications for oxytocin administration K Discuss fetal and maternal complications of abnormal labor K Describe methods of fetal surveillance K List abnormal labor patterns Level of Competence Objective

6. Learning Objectives ET-22 APGO Medical Student Educational Objectives 8 th Ed. 2004 K Discuss strategies for emergency management of breech, shoulder dystocia and cord prolapse K List indications for VBAC Level of Competence Objective

7. Terminology Gravidity #of current and completed pregnancies of any kind Parity # of completed pregnancies ≥ 20 weeks not delivered infants (e.g. twins)

8. Terminology Nullipara Primipara Multipara Grand Multipara

9. Terminology TPAL Nomenclature: T = Term deliveries ≥ 37 wks P = Preterm deliveries < 37 wks A = Abortions (< 20 wks) L = Living children

10. G3/P1-0-1-1: Terminology

11. G3/P1-0-1-1: 3rd Pregnancy 1 Term delivery 0 Preterm deliveries 1 Abortion 1 Living child Terminology

12. G5/P2-1-1-0: Terminology

13. G5/P2-1-1-0: 5th Pregnancy 2 Term deliveries 1 Preterm delivery 1 Abortion 0 Living children Terminology

14. G2/P0-2-0-3: Terminology

15. G2/P0203: 2nd Pregnancy 0 Term deliveries 2 Preterm deliveries 0 Abortions 3 Living children Terminology

16. Fetal Presentation Attitude Fetal Lie Fetal Position Fetal Station Terminology

17. Designates the fetal part over the pelvic inlet Fetal Presentation

18. Fetal Presentation Presentation % Incidence Cephalic 96.8 --- Breech 2.7 1:36 Transverse 0.3 1:335 Compound 0.1 1:1000 Face 0.05 1:2000 Brow 0.01 1:10,000 Williams Obstetrics, 21 st Ed. 452.

20. Cephalic Presenting Diameters FACE SINCIPUT MILITARY BROW VERTEX FLEXED Figure 9-2 Lateral view of the fetal skull showing the prominent landmarks and the anteroposterior diameters.

21. The degree of flexion a fetus assumes during labor or the relation of the fetal parts to each other Fetal Attitude

22. Variations in Fetal Attitude SINCIPUT, MILITARY BROW FACE VERTEX, FLEXED

23. Fetal Lie Refers to the relation of the long axis of fetus (back) to the long axis of the mother: ------ Transverse ------ -------------- Longitudinal ----------------

24. Diagnosis of Fetal Presentation Abdominal Palpation - Leopold’s Maneuvers

26. Diagnosis of Fetal Presentation Abdominal Palpation - Leopold’s Maneuvers Vaginal Examination Auscultation Sonography

27. Fetal Position Refers to the relation of an arbitrarily chosen portion of the fetal presenting part to the right or left side of the maternal birth canal Reference points (denominators) are: Fetal occiput Fetal chin (mentum) Fetal sacrum

28. Fetal Head: Landmarks Figure 9-1 Superior view of the fetal skull showing the sutures, fontanelles, and transverse diameters.

29. Occiput Presentation

30. Fetal Position OP LOT OA ROT LOP ROP LOA ROA LOT: 40% ROT: 20% OP: 20%

31. Fetal Position ?????

32. Fetal Position Left Occiput Anterior

33. Fetal Position ?????

34. Fetal Position Right Occiput Posterior

35. Fetal Position ?????

36. Fetal Position Left Occiput Transverse

37. The relationship of the fetal presenting part to the level of the ischial spines Fetal Station

38. Fetal Station World Health Organization: Managing Complications in Pregnancy and Childbirth www.who.int/reproductivehealth/impac/Clinical_Principles/Normal_labour_C57_C76.html

39. Clinical Correlation Correct identification of fetal position relative to the birth canal is critical! Document the following: Fetal Lie Fetal Presentation Fetal Position Fetal Station

40. Labor

41. Terminology False Labor (Braxton-Hicks ctx) May be present from first trimester Irregular, nonrhythmic True Labor Rhythmic contractions with cervical change

42. Essential Factors of Labor (The 3 P’s) Passage Powers Passenger

43. The 3 P’s of Labor Passage

44. Passage Bony Pelvis inlet midpelvis outlet Soft Tissue

45. Caldwell-Moloy Classification A P Gynecoid A P Android P A Platypelloid P A Anthropoid

46. Caldwell-Moloy Classification Gynecoid = 40 – 50% (10-15% AA) Android = 30% Anthropoid = 20% (40% in AA) Platypelloid = 2- 5%

47. Gynecoid Pelvis Round at the inlet, with the widest transverse diameter only slightly greater than the anteroposterior diameter Side walls straight Ischial spines of average prominence Well-rounded sacrosciatic notch Well-curved sacrum Spacious subpubic arch, with an angle of approximately 90 degrees

48. Android Pelvis Triangular inlet with a flat posterior segment and the widest transverse diameter closer to the sacrum than in the gynecoid type Convergent side walls with prominent spines Shallow sacral curve Long and narrow sacrosciatic notch Narrow subpubic arch

49. Anthropoid Pelvis A much larger AP than transverse diameter, creating a long narrow oval at the inlet Side walls that do not converge Ischial spines that are not prominent but are close, owing to the overall shape Variable, but usually posterior, inclination of the sacrum Large sacrosciatic notch Narrow, outwardly shaped subpubic arch

50. Pelvic Landmarks - Inlet Sacral promontory Illiopectineal line Symphysis pubis

51. mywebpages.comcast.net/wnor/pelvis.htm --Wesley Norman, PhD, DSc Georgetown University Pelvic Landmarks - Inlet

52. Pelvic Landmarks - Inlet

53. Vaginal Examination to Determine the Diagonal Conjugate

54. Pelvic Landmarks - Mid Ischial spines Sacrum Sacrosciatic notch

55. mywebpages.comcast.net/wnor/pelvis.htm --Wesley Norman, PhD, DSc Georgetown University Pelvic Landmarks - Mid

56. Assessment of Mid-pelvis

57. Pelvic Landmarks - Outlet Pubic arch Ischial tuberosities Sacrococcygeal joint

58. Pelvic Landmarks - Outlet Figure 9-4 Pelvic outlet and its diameters.

59. Assessment of Pelvic Outlet

60. Minimum Pelvimetrics * Average measurement, no minimum defined 8 Bituberous Outlet 10.5* Bispinous Midplane 11.5 Diagonal conjugate Inlet Length (cm) Diameter Pelvic Plane

61. The 3 P’s of Labor Powers

62. Powers 50 mm Hg or more Contractions occur q 2-3 minutes Upper uterus more active with pacemakers at cornual

63. The 3 P’s of Labor Passenger

64. Passenger Head is typically the largest structure Molding Smallest diameter of head: suboccipitobregmatic Abnormal lie or size or presentation can cause problems

65. Passenger: Fetal Head Considerations Bones in face fused but cranial vault has movable bones Molding is when bones overlap under pressure Sutures are membranous spaces between bones Fontanelles or “soft spots” are the intersections between sutures

66. Molding

67. Passage and Passenger Relationship Engagement –the fetal head is thru the pelvic inlet when fetal BPD reaches the ischial spines

68. Passage and Passenger Relationship Station - descent of the fetal BPD, relative to the level of the ischial spines.

69. COURSE OF NORMAL LABOR

70. Labor Definition The physiologic process by which the gravid uterus evacuates its contents at or near term by a mechanism involving coordinated sequence of periodic contractions of the myometrium effecting progressive cervical dilatation and fetal descent through the birth canal. - Emanuel A. Friedmin

71. First Stage of Labor Onset of true labor until cervix fully dilated: Latent Phase Active Phase

72. First Stage of Labor

74. First Stage of Labor

75. Second Stage of Labor Complete dilatation to delivery of the infant

76. Cardinal Movements of Labor Engagement, descent, flexion Internal rotation Complete rotation with beginning of extension Complete extension

77. External Rotation (Restitution) External rotation with delivery of Anterior shoulder Expulsion with delivery of Posterior shoulder

78. Third Stage of Labor Delivery of the infant to delivery of the placenta

79. Third Stage of Labor Placental separation: Uterus becomes firmer Gush of blood Uterus rises in abdomen as placenta passes into lower segment Lengthening of umbilical cord

80. Power: Forces of Labor First Stage of Labor Primary Forces = Uterine ctx to dilate cervix to 10 cm Second Stage of Labor Secondary Forces = Abdominal muscles to push fetus out after cervix is fully dilated Third Stage of Labor - Primary Forces = Uterine ctx to deliver placenta

81. INTRAPARTUM MANAGEMENT

82. Fetal Heart Rate Monitoring External: Indirect - Doppler ultrasound Internal: Direct – Scalp electrode

83. Fetal Heart Rate Monitoring External: Assessment of: baseline, variability, accelerations, decelerations Limitations: Maternal Body Habitus Maternal/Fetal Movement Artifact

84. Fetal Heart Rate Monitoring Internal: Assessment of: baseline, variability, accelerations, decelerations Limitations: Membranes must be ruptured Minimally invasive Increase risks of Hep B/HIV if mother + Maternal HR detected if FHR absent

85. Contraction Monitoring External: Indirect: Abdominal pressure electrode Internal: Direct: IUPC with pressure sensor

86. Contraction Monitoring External: - Can detect presence and interval of ctx, but not strength - Limitations: Maternal Body Habitus Maternal/Fetal Movement Artifact Factitious contractions

87. Contraction Monitoring Internal: - Assessment of BOTH frequency and intensity of contractions - Limitations: Membranes must be ruptured Minimally invasive

88. Intrapartum Monitors

89. Fetal Heart Rate Interpretation Assessment Quality of tracing Baseline fetal heart rate Describe overall variability Presence of accelerations? Presence of decelerations? Contraction frequency/intensity

102. Fetal Heart Rate Tracing

103. Fetal Monitoring Guidelines

104. Normal Labor Parameters Source: Modified from Friedman EA. Labor: Clinical Evaluation and Management, 2 nd ed. New York. Appletion-Century-Cronz 1370.43 2.5 h 57 min Second Stage 1.2 cm/h 3.0 cm/h Maximum Slope 3.3 h 54 min Deceleration 11.5 h 4.9 h Active 20.6 h 8.6 h Latent Lower Limit (95%) Mean Nulliparous Labor

105. Normal Labor Parameters Source: Modified from Friedman EA. Labor: Clinical Evaluation and Management, 2 nd ed. New York. Appletion-Century-Cronz 1370.43 50 min 14 min Second Stage 1.5 cm/h 5.7 cm / h Maximum Slope 53 min 14 min Deceleration 5.2 h 2.2 h Active 13.6 h 5.3 h Latent Lower Limit (95%) Mean Multiparous Labor

106. Abnormal Labor Assessment Clinical Caveat Labor dystocia requires a close assessment of the 3-P’s to determine the etiology and implement appropriate management changes to address the problem identified.

107. Adequate Labor Defined as > 200 Montevideo units (MVU) as measured by IUPC MVU = Sum of contraction strength for each contraction occurring over 10 minutes

108. MVUs = ????

109. MVUs = 270 “Adequate Labor”

110. 7 Labor Dysfunctions Prolonged Latent Phase Definition: > 20 hours nullipara > 14 hours multipara Treatment: “ Therapeutic rest” = sedatives 85% awaken in 6-10 hours and progress to active phase 10% have stopped contracting 5% continue to contract without progression, requiring uterine stimulation. Oxytocin

111. 7 Labor Dysfunctions Protracted Active Phase Definition: Cervical dilation < 1.2 cm/h nullipara Cervical dilation < 1.4 cm/h multipara Treatment: Evaluate passenger, passageway, power IUPC to calculate MVU (goal > 200) Oxytocin augmentation

112. 7 Labor Dysfunctions Protracted Deceleration Phase Definition: > 3 hours nullipara > 1 hour multipara Treatment: Same as for protracted active phase Evaluate passenger, passageway, power IUPC to calculate MVU (goal > 200) Oxytocin augmentation

113. 7 Labor Dysfunctions Secondary Arrest of Dilatation in Active phase Definition: Absence of cervical change over 2 hours* MVU > 200 Treatment: Cesarean delivery * Extension to 4 hours results in higher rate of vaginal delivery (92%) and is also acceptable

114. 7 Labor Dysfunctions Protracted Descent Definition: < 1 cm/h nullipara < 2 cm/h multipara Treatment: Same as for protracted active phase Evaluate passenger, passageway, power IUPC to calculate MVU (goal > 200) Oxytocin augmentation

115. 7 Labor Dysfunctions Arrest of Descent in Second Stage Definition: No descent of presenting part in: > 2 hours (or > 3 hours with CLE) nullipara > 1 hour (or > 2 hours with CLE) multipara Treatment: Continued observation Operative vaginal delivery Cesarean delivery

116. 7 Labor Dysfunctions Failure of Descent Definition: No descent in > 1 hour nullipara No descent in > 30 min multipara Treatment: Same as for protracted active phase Evaluate passenger, passageway, power IUPC to calculate MVU (goal > 200) Oxytocin augmentation

117. Labor Assessment Case 1 32 yo G1P0 36 weeks presented with contractions. Looks uncomfortable, and is contracting every 3 minutes but cervix is 2 cm and 50% effaced. Was seen the previous day with similar complaints and findings. Diagnosis: Management:

118. Labor Assessment Case 1 32 yo G1P0 36 weeks presented with contractions. Looks uncomfortable, and is contracting every 3 minutes but cervix is 2 cm and 50% effaced. Was seen the previous day with similar complaints and findings. Diagnosis: Prolonged latent phase Management: “ Therapeutic Rest”

119. Labor Assessment Case 2 24 yo P1001 39 weeks presented in labor. Contracting every 3 minutes but looks comfortable. Progressed from 4 to 6 centimeters in 6 hours. Membranes intact. Estimated fetal weight – 3000 grams. Pelvis adequate on examination. Vertex presentation. Diagnosis: Management:

120. Labor Assessment Case 2 24 yo P1001 39 weeks presented in labor. Contracting every 3 minutes but looks comfortable. Progressed from 4 to 6 centimeters in 6 hours. Membranes intact. Estimated fetal weight – 3000 grams. Pelvis adequate on examination. Vertex presentation. Diagnosis: Protracted active phase likely secondary to inadequate labor (insufficient power) Management: Amniotomy, Oxytocin augmentation +/- IUPC

121. Labor Assessment Case 3 32 yo P0000 Class C diabetic at 40 weeks undergoing labor induction. Contracting every 2-3 minutes. 7 cm dilation x 4 hours. Confirmed adequate labor with intrauterine pressure catheter. Membranes ruptured, Estimated fetal weight – 4200 grams. Pelvis adequate on examination. Vertex presentation. Diagnosis: Management:

122. Labor Assessment Case 3 32 yo P0000 Class C diabetic at 40 weeks undergoing labor induction. Contracting every 2-3 minutes. 7 cm dilation x 4 hours. Confirmed adequate labor with intrauterine pressure catheter. Membranes ruptured, Estimated fetal weight – 4200 grams. Pelvis adequate on examination. Vertex presentation. Diagnosis: Arrest of dilatation likely secondary to cephalopelvic disproportion/fetal macrosomia (Passenger too big for pelvis) Management: Cesarean Delivery

123. Labor Assessment Case 4 28 yo P0101 at 42 weeks presented in labor. History of previous MVA with pelvic fracture. Contracting every 2-3 minutes. 6 cm dilation x 4 hours. Confirmed adequate labor with intrauterine pressure catheter. Membranes ruptured, Estimated fetal weight – 3200 grams. Constricted pelvic inlet with non-engaged fetal head. Vertex presentation. Diagnosis: Management:

124. Labor Assessment Case 4 28 yo P0101 at 42 weeks presented in labor. History of previous MVA with pelvic fracture. Contracting every 2-3 minutes. 6 cm dilation x 4 hours. Confirmed adequate labor with intrauterine pressure catheter. Membranes ruptured, Estimated fetal weight – 3200 grams. Constricted pelvic inlet with non-engaged fetal head. Vertex presentation. Diagnosis: Arrest of dilatation likely secondary to cephalopelvic disproportion/abnormal pelvis (Pelvis too small for pelvis) Management: Cesarean Delivery