1 / 38

components of labour

The Powers. Secondary powers:

niveditha
Download Presentation

components of labour

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

    1. COMPONENTS OF LABOUR The powers Uterine contractions The passages bony pelvis, and soft tissues The passenger Fetus

    2. The Powers Secondary powers: # voluntary uterine contractions- abdominal muscles. # leads to expulsion of the baby. - Retraction: Progressive shortening of uterine smooth muscle cells in the upper portion of the uterus as labor progresses.

    4. The Passages Pelvic Anatomy: # Bony pelvis &diameters. # Pelvic Floor. Pelvic Types.

    5. Female Pelvic anatomy

    6. Anatomy Pelvic brim (The inlet of the pelvis): - Transverse diameter of inlet: 13.5 cm - AP diameter of inlet: 11 cm - Angle of inlet is 60° to the horizontal in erect position.

    7. Anatomy Pelvic mid cavity: It is almost round, having similar AP and transverse diameters (12 cm). The pelvic axis describes the imaginary curved line which shows the path that the center of fetal head takes during its passage through the pelvis.

    8. Anatomy Pelvic outlet: Transverse Diameter: 11 cm. AP diameter: 13.5 cm. Inlet: Transverse diameter is wider. Outlet: AP diameter is wider.

    9. Anatomy The pelvic floor is formed by the two levator ani muscles which forms, along with its fascia, a gutter during the second stage of labor.

    10. Pelvic Types Gynecoid (Classic type): - Found in 50% of women. - It has a cylindrical shape. - Is most favorable. - Fetal head usually assumes an occipito- anterior position in this type. 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-curved sacrum Spacious subpubic arch, with an angle of approximately 90 degrees

    11. Pelvic Types Android: - Typical male pelvis. - 30% of women. - limited space at inlet and gets narrower as you go down the pelvis (funneling). - Fetal head is forced to be in occipito-anterior position. - The angle of the pubic arch is less than 90 degrees. Deep transverse arrest of descent is common at midpelvis.

    12. Pelvic Types Anthropoid: - Resembles that of the anthropoid Ape. - 20% of women. - Fetal head engages in the AP diameter of pelvis (which is longer than transverse at inlet in this case). - Persistent occipito-posterior ` position.

    13. Pelvic Types Platypelloid: - A flattened gynecoid pelvis. - 3% of women. - Oval shaped inlet with wide transverse diameter. - A more gentle curve. - Fetal head has to engage in the transverse diameter. Risk of obstructed labor

    14. Pelvic Types Note that all pelvic measurements relates to bony pelvis. As the pelvic ligaments loosen in pregnancy. The pelvis is often more flexible than the measurements would suggest which is why the pelvic measurements may not be helpful.

    16. Passenger Fetal skull is the largest and the least compressible part, thus it is the most important part of delivery whatever the presentation is. The skull is made of: Vault, Face and Base. At the time of labor only unossified membranes at the sutures join the bones of the vault, unlike the face and the base which are firmly united.

    17. Passenger Between the bones there are four membranous sutures: Sagittal, Frontal, Coronal and Lambdoidal. Fontanels are the junction of the various sutures: Anterior fontanel (bregma) and Posterior fontanel. Vertex is the area of fetal skull bounded by two parietal eminences laterally and the Ant. and Pos. fontanels.

    18. Fetal Skull 1. Coronal Suture 2. Anterior Fontanel (Bregma) 3. Anterolateral Fontanel 4. Squamosal Suture 5. Posterolateral Fontanel 6. Lamdoidal Suture 7. External Acoustic Meatus 8. Sagittal Suture 9. Posterior Fontanel

    19. Diameters of the skull The longitudinal diameters that presents in a well-flexed head is the suboccipito-bregmatic diameter (9.5cm). The longitudinal diameters that presents in a less flexed head is the suboccipito-frontal diameter (10cm).

    20. Diameters of the skull With further extension of the head the occipito-frontal diameter present (11.5cm). The greatest longitudinal diameter that may present is the mento-vertical diameter (Brow presentation) (13cm). The extension of the fetal head beyond this point results in the submento-bregmatic diameters (9.5cm).

    22. Mechanism of Labor A series of changes in position and attitude the fetus undergoes during its passage through the birth canal. The following is a description for this mechanism in a vertex presenting fetus in a gynecoid pelvis.

    23. Movements Engagement. Descent. Flexion. Internal rotation. Extension Restitution. External rotation. Shoulders delivery. Delivery of the body.

    24. Mechanism of Labor Engagement: (Transverse Position) Engagement is said to have occurred when the widest part of the presenting part has passed successfully through the inlet.

    25. Engagement

    26. Mechanism of Labor Descent: during first stage and first phase of second stage of labor descent occurs secondary to uterine contractions. In the active phase of second stage it is helped by voluntary use of abdominal muscles and the Valsava maneuver (pushing).

    27. Descent

    28. Mechanism of Labor Flexion: it is a passive movement due to resistance from the cervix, pelvic walls, and pelvic floor. It minimizes the presenting diameter (from occipitofrontal to suboccipitobregmatic).

    29. Flexion

    30. Mechanism of Labor Internal rotation: the occiput rotates anteriorly, sagittal suture lies in AP diameter of pelvic outlet (widest diameter), this probably occurs as the fetal head meets the muscular sling of the pelvic floor.

    31. Internal rotation

    32. Mechanism of Labor Extension: occiput escapes from underneath the symphysis pubis and distends through the vulva. Episiotomy might be needed to reduce pernial resistance. Crowning: When the largest diameter of fetal head is encircled by the vulvar ring (vertex reached a +5 station). Further extension, using the symphysis pubis as a fulcrum, leads to appearance of the bregma, followed by the face and the chin.

    33. Extension

    34. Mechanism of Labor Restitution: As soon as head escapes from the vulva it aligns itself with the shoulders. The occiput rotates one eighth of a circle (neck untwists turning the head sideways). External rotation: Shoulders rotate to the AP plane. Occiput rotates a further one eighth of a circle to the transverse position.

    35. External rotation

    36. Mechanism of Labor Delivery of shoulders and body: Anterior shoulder delivers first followed by posterior shoulder. Rest of fetal body is normally delivered easily.

    38. Thank you

More Related