FEMALE PELVIS

FEMALE PELVIS IN RELATION TO CHILD BIRTH

1. FEMALE PELVIS IN RELATION TO CHILD BIRTH 9/25/2019 SUZAN GURTI 1 SESSION 3

2. Related tasks 9/25/2019 SUZAN GURTI 2 Describe the structure of the female pelvis( bones,ligaments,joints ) Identify types of pelvis Describe pelvis diameters and landmarks Draw and label female pelvis

3. THE FEMALE PELVIS 9/25/2019 SUZAN GURTI 3 The female pelvis is the bonny compartment which supports the vertebrae column, and its articulation with the lower limbs, it permits a person to sit and kneel. It forms a bonny passage through which the fetus passes during labour . It comprises of four bones Two innominate or unnamed bones One sacrum One coccyx

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7. INNOMINATE BONES 9/25/2019 SUZAN GURTI 7 Is made up of three bones: Illium , Ischium and the Pubis The illium Is the large flared-out part; when the hand is placed on the hip it rests on the iliac crest, which is the upper border. At the front of the iliac crest can be felt a bony prominence known as the anterior superior iliac spine.

8. 9/25/2019 SUZAN GURTI 8 Below is the anterior inferior iliac spine. There are two similar points at the other end of the crest, posterior superior and posterior inferior iliac spines. The ischium Is the thick lower part which has a large prominence known as the ischial tuberosity , on which the body rests when sitting. Behind and a little above the tuberosity is an inward projection known as, the ischial spine. During labor the station of the fetal head is estimated In relation to the ischial spines.

9. 9/25/2019 SUZAN GURTI 9 The pubic bone This bone forms the anterior part. It has a body and two oar-like projections, the superior ramus and the inferior ramus . The two pubic bones meet at the symphisis pubis and the two inferior rami form the pubic arch, merging into a similar ramus on the ischium . The space enclosed by the body of the pubic bone, the rami and the ischium is called the obturator foramen.

10. 9/25/2019 SUZAN GURTI 10 The ischium contains a deep cup to receive the head of femur, called acetabulum . On the lower boarder of the innominate bone are found two curves. One extends from the posterior inferior iliac spine up to the ischial spine and is called greater sciatic notch. The other lies between the ischial spine and ischial tuberosity and is the lesser sciatic notch.

11. THE SACRUM 9/25/2019 SUZAN GURTI 11 The sacrum is a wedge-shaped bone consisting of five fused vertebrae. The upper border of the first sacral vertebra juts forward and is known as sacral promontory. The anterior surface of the sacrum is concave and is referred to as the hollow of the sacrum. Laterally the sacrum extends into a wing or ala. Four pairs of holes or foramina pierce the sacrum and, through these, nerves from the cauda equina emerge to supply the pelvic organs. The posterior surface is roughened to receive attachment of muscles

12. THE COCCYX 9/25/2019 SUZAN GURTI 12 Is a vestigial tail which consist of four fussed vertebral forming a small triangular bone. The coccyx articulates with the fifth sacral vertebra to form the sacrococcygeal joint. During birth the coccyx is usually forced backwards to allow more room for the fetus to pass.

13. 9/25/2019 SUZAN GURTI 13 Pelvic joints There are four pelvic joints; One symphisis pubis Two sacro iliac joints One sacrococcygeal joint . The pelvic joints are not very mobile in non pregnant woman, but during pregnancy the endocrine activity causes the ligaments of the joints to soften which allows the joints to soften and stretch during labour

14. 9/25/2019 SUZAN GURTI 14 The symphisis pubis It is formed at the junction of the two pubic bones, which are united by a pad of cartilage. It widens during the last months of pregnancy and, because of its increased mobility may cause the pregnant woman pain as she walks.

15. 9/25/2019 SUZAN GURTI 15 Sacroiliac joints These are the strongest joint in the body. They join the sacrum to the ilium and thus connect the spine to the pelvis. During pregnancy much stress is placed on these joints and multipara often complain of backache during pregnancy and for few weeks following delivery.

16. 9/25/2019 SUZAN GURTI 16 Sacrococcygeal joint This joint is formed where the base of the coccyx articulates with the tip of the sacrum. The joint allows the coccyx to move backwards during birth, thus widening the outlet of the pelvis.

17. 9/25/2019 SUZAN GURTI 17 pelvic ligaments Each of the pelvic joints is held together by ligaments; Interpubic ligaments at the symphysis pubis Sacroiliac ligament, Sacrococcygeal ligaments.

18. 9/25/2019 SUZAN GURTI 18 The other two ligaments important in midwifery are:- Sacrotuberous ligaments :- from the sacrum to the ischial tuberosity Sacrospinous ligament: - from the sacrum to the ischial spine.

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20. 9/25/2019 SUZAN GURTI 20 The pelvic floor The pelvic floor is formed by the soft tissues that fill the outlet of the pelvis. Functions The pelvic floor supports the weight of the abdominal and pelvic organs. Its muscles are responsible for the voluntary control of micturation and defecation and play an important role in sexual intercourse. During child birth it allows the passive movements of the fetus through the birth canal

21. 9/25/2019 SUZAN GURTI 21 Muscle layers The superficial layer which is composed of five muscles:- The external anal sphincter encircles the anus and is attached behind by a few fibers to the coccyx The transverse perineal muscles pass from the ischial tuberosity to the centre of the perineum.

22. 9/25/2019 SUZAN GURTI 22 The bulbocavernosus muscles pass from the perineum forward around the vagina to the copra cavernosa of the clitoris just under the pubic arch. The ischial cavernosa muscles pass from the ischial tuberosities along the pubic arch to the copra cavernosa . The membranous sphincter of the urethra is composed of muscle fibres passing above and below the urethra and attached to the pubic bone.

23. 9/25/2019 SUZAN GURTI 23 The deep layer This layer is composed of three pairs of muscles which together re known as levator ani muscles. Each levator ani muscle (left and right) consist of the following: The pubococcygeus muscle from the pubis to the coccyx The iliococcygeal muscle from the fascia covering the obturator intenus muscle to the coccyx The ischiococcygeus muscle from the ischial spine to the coccyx

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25. DIAMETERS OF PELVIS 9/25/2019 SUZAN GURTI 25 The true pelvis It is the bonny canal through which the fetus must pass during birth. It has a brim, cavity and outlet The pelvic brim The brim is round except where the sacral promontory projects into it. The promontory and wings of sacrum form its posterior boarder, the iliac bones its lateral boarders and the pubic bone its anterior boarder

26. 9/25/2019 SUZAN GURTI 26 The land marks of the brim are: Sacral promontory Sacral ala or wing Sacro iliac joint Iliopectineal line Iliopectineal eminence

27. 9/25/2019 SUZAN GURTI 27 Superior ramus of the pubic bone Upper inner boarder of the body of pubic bone Upper inner boarder of the symphysis pubis Diameters of the brim Three diameters are measured

28. 9/25/2019 SUZAN GURTI 28 The anteroposterior diameter It is a line from the sacral promontory to the upper boarder of the symphysis pubis. When the line is taken to the upper boarder of the symphysis pubis it is called the anatomical conjugate and is measured 12 cm; When it is taken to the posterior boarder of the upper surface 1.25 cm lower is called obstetrical conjugate and measures 11 cm, it represent the available space for the passage of the fetus.

29. 9/25/2019 SUZAN GURTI 29 The diagonal conjugate is measured from the lower boarder of the symphysis pubis to the sacral promontory it may be estimated on vaginal examination as part of pelvic assessment and should measure 12-13 cm.

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31. 9/25/2019 SUZAN GURTI 31 The Oblique diameter It is a line from one sacroiliac joint to the iliopectineal eminence on the opposite side and measures 12 cm. There are two diameters left and right oblique diameters each takes its name from the sacroiliac joint from which it arises.

32. 9/25/2019 SUZAN GURTI 32 The transverse diameter It is a line between the points further apart on the iliopectineal line and measures 13 cm. Another diameter is measured, the sacrocotyloid diameter from the sacral promontory to the iliopectineal eminence on each side and measures 9-9.5 cm. It is only important in posterior positions of the occiput .

33. 9/25/2019 SUZAN GURTI 33 The pelvic cavity The cavity extends from the brim above to the cavity below. The anterior wall is formed by the pubic bone and the symphysis pubis and is 4 cm long. The posterior wall is formed by the curve of sacrum and is 12 cm long. Its lateral walls are the sides of the pelvis The cavity is circular in shape its diameters cannot be measured but are considered to be 12 cm.

34. 9/25/2019 SUZAN GURTI 34 The outlet Two outlets are described, the anatomical and obstetrical . The anatomical outlet is formed by the lower border of the pelvic bones and the sacrotuberous ligaments. The obstetrical outlet is the space between the narrow pelvic strait and the anatomical outlet. The narrow pelvis strait lies between the sacrococcygeal joint, the two ischial spines and the lower boarder of symphysis pubis. There are three diameters;-

35. 9/25/2019 SUZAN GURTI 35 The anteroposterior diameter It is a line from the lower boarder of the symphysis pubis to the sacrococcygeal joint. It measures 13 cm. the coccyx may be deflected backwards during labour . The dimeter indicates the space available during delivery. The oblique diameter Between the obturator foramen and the sacrospinous ligaments there are no fixed points the measurement is taken to be 12 cm.

36. 9/25/2019 SUZAN GURTI 36 The transverse diameter This is a line between the two ischial spines and measuers 10-11 cm it is the narrowest diameter in the pelvis.

37. 9/25/2019 SUZAN GURTI 37 The false pelvis The false pelvis is the part situated above the brim. It is formed by the upper flared-out part of the iliac bones and protects the abdominal organs.

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39. TYPES OF PELVIS 9/25/2019 SUZAN GURTI 39 There are four types of pelvis Pelvises are classified according to shape of the brim. Much important is the individual woman’s pelvic capacity and whether it is adequate for the passage of the child she is carrying.

40. 9/25/2019 SUZAN GURTI 40 Gynaecoid pelvis It is the ideal pelvis for child bearing Its main features are rounded brim, straight side walls, and shallow cavity with broad well curved sacrum, blunt ischial spines, wide sciatic notch and a pubic arch of 90 degrees. It is found in women with average size and height with shoe size of 4 or larger.

41. 9/25/2019 SUZAN GURTI 41 All diameters are reduced but are in proportion. It is normally found in women of small stature less than 1.5 m in height with small hands and feet.

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43. 9/25/2019 SUZAN GURTI 43 The android pelvis It resembles the male pelvis. Its brim is heart shaped with a narrow fore pelvis. It is a funnel shape with a deep cavity and straight sacrum. The ischial spines are prominent and the sciatic notch is straight. The sub pubic angle is less than 90 degrees, it is found in heavily built women The heart shaped brim favors posterior position of the occiput and is the least suited for child bearing.

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45. 9/25/2019 SUZAN GURTI 45 The anthropoid pelvis It has a long oval brim in which the anteroposterior diameter is long than the transverse. The sacrum is long and deeply concave. The ischial spines are not prominent, the sciatic notch and sub pubic angle are very wide. It is found in women who are tall with narrow shoulders. Labour does not usually present any difficulties.

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47. 9/25/2019 SUZAN GURTI 47 The Platypeloid Pelvis This flat pelvis has a kidney-shaped brim in which anteroposterior diameter is reduced and the transverse increased. The sacrum is straight and the cavity is shallow. The ischial spines are blunt and the sciatic notch and sub pubic angle are wide. The head must engage with the sagittal suture in the transverse diameter but usually descends without difficulty

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