MECHANISM OF LABOR.(Cardinal Movement)Mechanism of labour a series of event that occur in the head in the process of adaptation during its journey through the pelvis is called mechanism of labour.

Mechanism of labour a series of event that occur in the head in the process of adaptation during its journey through the pelvis is called mechanism of labour.

1. MECHANISM OF LABOR Presented by - Pragati rawat

2. DEFNITON The series of movements that occur on the head in the process of adaptation during its journey through the pelvis is Called mechanism of Labor. - D.C.Dutta Presentation title ‹#›

3. The mechanism of Labor , also known as the Cardinal movement, involves changes in the Position of the fetus head during its passage through the birth canal. Presentation title ‹#›

4. Description of Normal Labour :-

5. ‹#› The Lie → Longitudinal The presentation → Cephalic The position → Right or left occiput - anterior The attitude →Good flexion The denominator → Occiput The presenting part → posterior part of the anterior Parietal bone /vertex. f etal

6. . . Descent take place throughout labor. Whichever part lead & first meets the resistance of the pelvic floor will rotate forwards until it comes under the symphysis pubis. Whatever emerges from the pelvis will pivot around the pubic bone. Presentation title ‹#› Principles of Mechanism of Labour -

7. Presentation title ‹#›

8. Presentation title ‹#›

9. CARDINAL MOVEMENT ENGAGEMENT DESCENT FLEXION INTERNAL ROTATION OF THE HEAD CROWNING EXTENSION OF THE HEAD RESTITUTION INTERNAL ROTATION OF SHOULDER EXTERNAL ROTATION OF HEAD BIRTH OF SHOULDER AND TRUNK. ‹#›

10. Engagement → (Baby dropping) ‹#› - when the bi-parietal diameter , the greatest transverse diameter of the fetal head in vertex presentation passes through the pelvic inlet and engage in the true pelvic is said to be engaged. [ Note - In primigravida, it usually Occur 12 hours, In multipara it will occur within 6 hours ] → Leading point of the fetal skull is at 'O'station

11. 2- Descent ‹#› Descent of the fetus is a continuous movement it is slow or insignificant in the first stage of labor but pronounced in the second stage, it complete with the expulsion of the fetus. It is due to contraction and retraction of uterine muscle (primary force) upto in the second stage by bearing down effort (secondary force)

12. In primi gravida with prior Engagement of the head, there is practically no Descent in the first stage, while In multipara, Descent start with Engagement head is expected to reach the pelvic floor by the time the cervix is fully dilated. ‹#›

13. FACTOR FACILITATING DESCENT ARE :- uterine contraction and retraction Bearing down effort and Straightening of the fetal void especially after rupture of Membrane Presentation title ‹#›

14. 3- Flexion ‹#› As soon as descending head meets resistance from -the Cervix, pelvic wall or pelvic floor during descent, full flexion is achieved The chin is brought into contact with the fetal thorax & the presenting /engaging diameter of fetal head Changes from occipito frontal (11.0cm) to suboccipito-bregmatic (9.5cm) for optimal passage of fetal head through the pelvic .

15. Internal rotation of the head Presentation title ‹#› The Occiput rotate through 1/8 the of the circle to lie under the pubic arch .The pelvic floor has a gutter shape with a forward and downward slope encourage the fetal head to rotate from a left or right Occipto -transverse position to an occipto-anterior positions

16. 5- CROWNING Presentation title ‹#› After internal rotation of the head further descent occure until the subocciput lies underneath the pubic arch, At this stage, widest diameter of the head (biparietal diameter) stretches the vulval outlet without any recession of the head even after the contraction is over called ‘Crowning of the head ’

17. Presentation title ‹#›

18. 6. EXTENSION ‹#› Extension is a result of two forces The first force is exerted by the uterine contractions and abdominal muscles contraction pushes the head in a downward direction (posterior ) While the second force supplied by the resistant pelvic floor muscles and pubic symphysis acts anteriorly in the upward and forward direction.

19. The occiput slip beneath the suprapubic arch allowing the head to extends .The fetal head is now born and will facing the maternal back with the occiput anterior. Presentation title ‹#›

20. 7. Restitution Presentation title ‹#› It is a External rotation in which return of the fetal head to the Correct anatomic position in relation to the fetal torso

21. 8.External rotation Presentation title ‹#› As the head is born , the shoulder enter the maximum diameter (the transverse diameter ) of the maternal pelvic inlet. As they descend they descend through the canal ,the shoulder rotate (just as the head did in internal rotation ) and , they do so , the head (outside the body now ) rotates 90 degree. The shoulder now lie in the anteroposterior diameter behind the maternal symphysis pubis .

22. 9. Delivery of the baby Presentation title ‹#› Delivery of the anterior shoulder is aided by gentle downward traction on head . The posterior shoulder is then delivered by gentle upward traction on the head. Following these maneuvers the body , legs,and feet delivered with gentle traction on the shoulders.

23. Summary Presentation title ‹#›

24. Thank you