Cephalopelvic disproportion and it's management

Cephalopelvic disproportion

1. CEPHALOPELVIC DISPROPORTION DR.SABITHA BAANU FIRST YEAR POST GRADUATE DEPARTMENT OF OBSTETRICS AND GYNAECOLOGY

2. TOPICS : 1.Fetal skull 2.Maternal pelvis 3.Cephalopelvic disproportion

3. FETAL SKULL : It consists of the vault ,the base and the face . Vault –frontal (2) , Parietal (2) , occipital (1) , temporal (2) and the wings of sphenoid . Sutures – B ones united by thin piece of membrane - Frontal suture - Sagittal suture -Coronal suture - Lambdoid suture -Temporal suture

4. Fontanelle : Area covered by membrane in which suture lines meet Anterior fontanelle - bregma Posterior fontanelle – lambda Anterior fontanelle : Formed by frontal , sagittal and Coronal sutures Diamond shaped which measures 2-3 cm Ossifies at 1 – 1½ of age

5. 2. Posterior Fontanelle : Formed by sagittal and lambdoid sutures . Y shaped triangular in shape Ossifies at 2-3 months of age .

6. DIAMETERS OF FETAL SKULL :

7. TRANSVERSE DIAMETERS : Biparietal diameter – between Two Parietal eminences – 9.5 cm Bitemporal diameter – Between antero inferior ends of coronal suture ( 8 cm )

8. MOULDING : As the fetal skull bones are United by fibrous tissue, they can slide and override each other to adjust to the shape and size of maternal pelvis . Grading – Grade 1 – sutures opposed Grade 2 – suture overlapped, but reducible Grade 3 – sutures overlapped, but irreducible

9. CLINICAL SIGNIFICANCE OF SUTURES AND FONTANELLES OF FETAL SKULL: In well flexed head in occipitoanterior position, posterior fontanelle is palpable. In occipitoposterior position , anterior fontanelle is easily palpable , posterior fontanelle may be palpable at higher level. In brow presentation, anterior fontanelle is palpable with forehead up to orbital ridges . In face presentation , no fontanelle is palpable.

10. MATERNAL PELVIS

11. 4 bones – two innominate bones , a sacrum and a coccyx 4 joints – 2 sacroiliac joints , sacrococcygeal joint and symphysis pubis

12. TRUE PELVIS 1) Inlet – Diameters – 1. Anteroposterior diameter True / Anatomical conjugate – 11cm Obstetric conjugate – 10 cm Diagonal conjugate – 12.5 cm 2. Transverse Diameter – 13. 5cm 3. Oblique diameter – 12 cm 4. Sacrocotyloid diameter – 9 cm 5. Posterior sagittal diameter – 5 cm

13. Outlet : 1. Anteroposterior diameter – 12 cm. From inferior border of pubis symphysis to posterior aspect of tip of sacrum 2 . Transverse diameter – 10.5 – 11 cm between inner edges of ischial tuberosities 3 . Posterior sagittal diameter – 7 cm From middle of transverse diameter to tip of sacrum

14. Pelvic cavity : Lies between inlet and outlet , anteriorly by pubis symphysis and posteriorly by sacrum 2 planes – plane of greatest pelvic dimension and plane of least pelvic dimension Plane of greatest pelvic dimension – Extends from junction of S2 and S3 to the posterior surface of pubis symphysis -12.5 cm Laterally by ischial bones – 12.75 cm Plane of least pelvic dimension ( Midpelvis ) – Extends from junction of S4 and S5 to lower border of pubis symphysis– 11.5 cm Laterally by ischial spines – 10 cm Posterior sagittal diameter – from interischial diameter to junction of S4 and S5 – 6cm

15. CALDWELL AND MOLOY’S CLASSIFICATION OF PELVIS :

16. CLINICAL SIGNIFICANCE OF PELVIS : Small gynecoid pelvis : causes cephalopelvic disproportion . Normal shape with all diameter are proportionately reduced . Android pelvis : Occipitoanterior posterior is common Anthropoid pelvis : persistent occipito position is common Platypelloid pelvis : Asynclytic engagement occurs and face presentation can occur .

17. CEPHALOPELVIC DISPROPORTION

18. It is the anatomical / mechanical disproportion between the fetal head and the maternal pelvis for that particular pregnancy. It may either due to diminished pelvic capacity or abnormal fetal size Does not necessarily recur in subsequent pregnancy

19. CONTRACTED PELVIS : This is a permanent deformity of the pelvis in which one or more diameters of pelvis are reduced. At the level the inlet – obstetric conjugate < 10 cm At the level of Midpelvis – interspinous diameter < 10 cm ( <8 cm is definitely contracted ) At the level of outlet – intertuberous diameter < 8 cm

20. CAUSES OF CONTRACTED PELVIS : Lower limb shortening or deformities caused by fracture of pelvic/lower limbs Poliomyelitis Tuberculosis of hip joints Kyphosis and scoliosis affecting lumbar region Rickets and osteomalacia -rarely Naegele’s pelvis and Robert’s pelvis

21. Contracted Inlet and its effects : Diagonal conjugate < 11.5 cm or calculated obstetric conjugate < 10 cm Obstetric conjugate = diagonal conjugate – 1.5 to 2 cm EFFECTS : Malpositions and malpresentations ( deflexed head , brow/face presentation, transverse lie. Premature rupture of membranes or spontaneous rupture of membranes early in labour.

22. Contracted Midpelvis and it’s effects : Interspinous diameter < 10 cm . Mid-pelvic EFFECTS : Transverse arrest of labour
Prolonged labour
Obstructed labour

23. Contracted outlet and it’s effects : Intertuberous diameter < 8 cm EFFECTS : Third or fourth degree perineal tears

24. DIAGNOSIS OF CPD : HISTORY : A history of prolonged labour ,forceps delivery , cesarean section, fetal asphyxia , still birth , neonatal death in the absence of other etiological factors suggest contracted pelvis or CPD . History of post polio residual paralysis , fracture in lower limbs , Tb in pelvic joints suggest contracted pelvis

25. EXAMINATION : Short statured women < 145 cm may have a small gynecoid pelvis , monitor for abnormal labour patterns and pelvic dystocia. Dystocia dystrophia syndrome – short , obese women may have Android pelvis Pendulous abdomen, deformities in lower spine , shortening of lower limb and tilting of pelvis Floating head in primigravida

26. ASSESSMENT OF PELVIS (CLINICAL PELVIMETRY) : Emptied bladder with dorsal position of the women . Inlet :

27. Cavity : Shape and inclination of sacrum – sacral concavity should be well developed so that bone at midpelvis and higher level cannot be reached. Side wall of pelvis – palpate from the pelvic brim to ischial spines ( straight , converging or diverging ) Ischial spines – palpated to see blunt (difficult to identify) , prominent (easily felt but not large ) , very prominent ( large and encroaching on mid plane ) Interspinous diameter – both spines touched simultaneously by 2 fingers , then it’s inadequate for a average sized baby. Sacrosciatic notch – sacrospinous ligament should admit 2 and ½ fingers

28. Outlet: Subpubic angle – normally admit 2 fingers Intertuberous diameter – interischial tuberosities should normally admit closed fist ( four knuckles )

29. ASSESSMENT OF CPD : ABDOMINAL METHODS : HEAD FITTING TEST :

30. 2. DONALD’S METHOD :

31. ABDOMINOPELVIC METHOD – THE MUNRO-KERR-MULLER METHOD :

32. Complications of CPD : Floating head PROM Malposition and Malpresentation Prolonged labour Obstructed labour and rupture uterus Cord prolapse , fetal distress , stillbirth Increased operative deliveries

33. Management of CPD : Elective cesarean section : Major degree CPD Obliquely contracted pelvis Minor disproportion with malpresentations or high risk pregnancies . Trial of labor : Minor degree CPD contraindications : Vertex presentation Major degree CPD Primigravida without comorbidities Malpresentations Platypelloid pelvis obstetric risk factors No mid cavity or outlet contractions Average sized baby

34. PROCEDURE OF TRIAL OF LABOUR IN CPD : Should be conducted where facilities cesarean section is available . Spontaneous onset of labor Women after getting consent , prepare her for both vaginal delivery and cesarean section. Once labour begins , monitor her by abdominal palpation , vaginal examination, partograph and vitals . For fetus – CTG For pain – epidural analgesia

35. GOOD PROGNOSTIC SIGNS : POOR PROGNOSTIC SIGNS Good uterine contactions . 1. Weak uterine contactions Early engagement of head. 2. Slow descent of head Cervix thinned and progressively dilated. 3. Rupture of membranes with Occipitoanterior position uneffaced and partially dilated cervix 4. Slow dilatation of cervix 5. Occipitoposterior position

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