Occipito posterior position

This topic contains definition, incidence, types, causes, diagnosis, mechanism, management of occipito posterior position and deep transverse arrest and manual rotation of occipito posterior position

1. MS. PRIYANKA GOHIL M.Sc. (N) OBG Nursing Tutor, MBNC OCCIPITO POSTERIOR POSITION

2. MALPOSITION “ Malposition refers to any position of the vertex other than the flexed occipito-anterior one.” OCCIPITO POSTERIOR POSITION “In a vertex presentation where the occiput is placed posteriorly over the sacroiliac joint, sacrum called occipito-posterior postion.”

3. Occiput placed over:- Right sacroiliac joint called RIGHT OCCIPITO POSTERIOR Occiput placed over:- Left sacroiliac joint called LEFT OCCIPITO POSTERIOR Traditionally called 3rd and 4rh position of the vertex.

4. Occiput placed over:- sacrum called DIRECT OCCIPITO POSTERIOR All the three positions are Primary (before the onset of labour ) or Secondary ( developing after labour starts )

5. In majority of cases (90 %) , ANTERIOR ROTATION of occiput occurs and follows the course like that of an occipito anterior position and it is favorable position But as the posterior position occasionaly gives rise to dytocia, it is described along with malpositions

6. INCIDENCE At onset of labour:- About 10 % Expected to be more during late pregnancy and less during late second stage of labour Right occipito posterior is 5 times more common than the left occipito posterior

7. Dextro-rotation of the uterus and the presence of sigmoid colon on the left, disfavor Left Occipito Posterior Position (Dextro-rotation is movement/rotation to the right/ clockwise, opp. is laevorotation)

8. CAUSES Shape of the pelvic inlet Fetal factors Uterine factor

9. Shape of the pelvic inlet More than 50 % cases are associated with the ANTHROPOID OR ANDROID PELVIC The wide occiput can comfortably be placed in the wider posterior segment of the pelvis

10. FETAL FACTORS Marked deflexion of the fetal head Cuases of deflexion:- High pelvic inclination (gedree of slopping) Anterior attachment of placenta Primary bradycephaly

11. High pelvic inclination Inclination of brim is high and the upper sacrum is relatively vertical and convex Occiput will be placed to posterior surface

12. Anterior attachment of placenta Well flexed attitude but convexity of maternal and fetal spine is opposite, which leads to deflexion of fetal head and thus the occiput with occupy the posterior part

13. Primary bradycephaly (flatened area at back of the skull) Diminishes the effective movement of flexion

14. Uterine factor Abnormal uterine contraction which may be cause or effect, lead to persistent deflexion and occipito posterior postion

15. DIAGNOSIS ABDOMINAL EXAMINATION On inspection abdomen looks flat below the level of umbelicus

16. UMBILICAL GRIP Fetal limbs are more easily palpable near the midline on either side The fetal back is felt far away from the midline on the flank and often difficult to outline clearly. The anterior shoulder lies far away from the midline

17. PELVIC GRIP Head is not engaged Sinciput not felt as in well flexed occipito posterior AUSCULTATION Intensity of fetal heart sound felt on the flank and often difficult to locate

18. VAGINAL EXAMINATION Elongated bag of membranes which is likely to rupture during examination Sagital suture occupies any obligue diameters of the pelvis Posterior fontanelle felt near the sacroiliac joint Anterior fontanelle felt more easily because of deflexion of the head, lower than posterior fontanelle

19. MECHANISM OF LABOUR IN FAVOURABLE: Flexion Internal rotation of the head (head 3/8 ant., shoulder 2/8): occupy RIGHT oblidue diameter in ROP and LEFT obligue diameter in LOP Further descent : as occipito anterior p. Restitution External rotation Birth of the shoulders and trunk

20. IN UNFAVOURABLE: Incomplete forward rotation: deep transverese arrest Non rotation Malrotation

21. Mechanism of “face to pubis” delivery Further descent occurs until the root of the nose Flexion occurs Restitution External rotation Persistant occipito-posterior

22. MANAGEMENT Early diagnosis Watchfull expectancy for decent and anterior rotation Early cesarean section: Anticipating prolonged labour, no progress of labour, Persistant of deflexion and non-rotation, Arrest labour, incoordinated uterine contraction, fetal distress

23. MANAGEMENT OF ARREST OPP 1. Arrest in transverse / obligue occipito posterior position:- Ventouse Alternative methods like mannual rotation and extraction, cesarean section and craniotomy 2. Occipitosacral arrest:- Forceps application followed by etraction as face-to-pubis Liberal mediolateral episiotomy should be done

24. DEEP TRANSVERSE ARREST The head is deep in to the cavity, sagital suture is placed in the transverse bispinous diameter and there is no progress in descent of the head even after 0.5 to 1 hour following full dilatation of the cervix

25. CUASES Pelvic structure Deflexion of the head Weak uterine contraction Laxity of pelvic floor muscles

26. DIAGNOSIS Head is engaged Sagital suture lies in transverse bispinous diameter Anterior fontanelle is palpable Faulty pelvic architecture

27. MANAGEMENT If Vaginal delivery not safe: Cesarean section If Vaginal delivery safe: ventouse, mannual rotation, forcep rotation

28. MANNUAL ROTATION OF OPP The mannual rotation can be accomplished with whole hand method or with half hand method. Steps:- Put the patient under general anesthesia Provide lithotomy position Maintain full surgical asepsis Catheterizaion should be done Identify direction of occiput by PV Exa.

29. WHOLE HAND METHOD:- Step I: Gripping of the head Step II: Rotation of the Head Step III: Application of forceps

30. Step I: Gripping of the head In ROP or ROT the Left hand and in LOP or LOT the Right hand is usually used. The correctsponding hand is introduced into the vagina in cone shapped manner after seperating the labia by two fingers of other hand.

31. In Occipito transverse position, the four fingers are pushed in the sacral hollow to be placed over the posterior parital bone and the thumb is placed over the anterior parital bone. In oblique posterior position, four fingers of patially supinated hand are placed over the occiput and the thumb is placed over the sinciput.

32. Step II: Rotation of the head Slight disimpaction may be needed for good grip. By the movement of pronation of the hand, the head is rotated to bring the occiput anterior along the shortest route. Simultaneouslty, the back of the fetus is rotated by the external hand from the flank to the midline.

33. This is an essential prerequisite, for anterior rotation of head. A little over rotation is desirable anticipating slight recurrence of malposition before the application of forceps.

34. In the Alternative method , the four fingers of the pronated right hand are placed over the sinciput and the thumb over the occiput in ROP. The head is rotated in the supination movement of the hand.

35. Step III: Application of the forceps Following Rotation, when the right hand is placed over the left side of the pelvis, left blade of the forcep is introduced. When the left hand is used, it is placed on the right side of the pelvis after rotation, as such the right blade is to be introduced first and the left blade is then to be introduced underneath the right blade.

36. While introducing the blades, it is preferable that an assistant fixes the head by suprapubic pressure in a manner of first pelvic grip. As it is a mid forceps application, axis traction device should be used.

37. DIFFICULTIES:- Failure to grip the head adequetly due to lack of space Failure to dislodge the head from the impacted position Inadequate anesthesia Wrong case selection

38. DANGERS - Accidental slipping of the head above the pelvic brim and prolapse of the cord It is better to be perform cesarean section in such a situation.

39. Half HAND METHOD: - Steps: The rotation is done only by using the right hand. The four fingers are introduced into the vagina and tangential pressure is applied on the head at the level of diameter of engagement.

40. The pressure is applied on the side and the parietal eminence of the head. In ROP or ROTpositions, the fingers are placed anterior to the head and the pressure is applied by the ulnar border of the hand. In LOP or LOT positions, the fingers are placed posteriorly and the pressure is applied by the radial border of the hand.

41. The force is applied intermittently till the occiput is placed behind the symphysis pubis.