Advanced Reproductive Dynamics Study Guide Worksheet PDF

1 Advanced Reproductive Dynamics ANW8000 Study Guide Worksheet Module 1 1.​ Label the pelvic structures in the following illustration. Amber (Coad et al., 2020) Anatomy & Physiology for Midwives, 4th...

1 Advanced Reproductive Dynamics ANW8000 Study Guide Worksheet Module 1 1.​ Label the pelvic structures in the following illustration. Amber (Coad et al., 2020) Anatomy & Physiology for Midwives, 4th ed., Ch. 2 pg. 55 a. Iliac crest b. Posterior superior iliac spine c. Sacrospinous ligament d. Ischial spine e. Sacrotuberous ligament 2.​ List the pelvic bones (bony pelvis). Amber (Pascali D.U., 2023). Oxorn-Foote Human Labor & Birth, 7th ed., Ch 1 pg 1 a. Innominate (there are two of this one) b. Sacrum c. Coccyx  2 3. Each innominate bone is formed by the fusion of the ileum, ischium and pubis around the acetabulum. Amber (Pascali D.U., 2023). Oxorn-Foote Human Labor & Birth, 7th ed., Ch 1 pg 1 4. List the landmarks on the Innominate bone below: Amber (Coad et al., 2020) Anatomy & Physiology for Midwives, 4th ed., Ch. 2 pg. 55 a. Anterior superior iliac spine g. Greater sciatic notch b. Symphysis pubis h. Ischial spine c. Obturator foramen i. Lesser sciatic notch d. Inferior ramus of pubic bone j. Ischial tuberosity e. Posterior superior iliac spine k. Inferior ramus of ischium f. Posterior inferior iliac spine  3 5. Name the following joints linking the bones of the pelvis. Describe each. Amber (Pascali D.U., 2023). Oxorn-Foote Human Labor & Birth, 7th ed., Ch 1 pg 3-4 a.​ Sacroiliac Joint - Lies between the articular surfaces of the sacrum and the ileum. The weight of the body is transmitted through it to the pelvis and then to the lower limbs. It is a synovial joint that permits a small degree of movement. b.​ Sacrococcygeal Joint - A synovial hinge joint between the fifth sacral and the first coccygeal vertebrae that allows both flexion and extension. Extension, by increasing the AP diameter of the outlet of the pelvis, plays an important role in parturition. c.​ Symphysis Pubis - A cartilaginous joint with no capsule and no synovial membrane. Normally, there is little movement. The posterior and superior ligaments are weak. The strong anterior ligaments are reinforced by the tendons of the rectus abdominis and the external oblique muscles. The strong inferior ligaments in the pubic arch are known as the arcuate pubic ligament. 6. Identify the superficial pelvic floor muscles in the image below: Amber (Coad et al., 2020) Anatomy & Physiology for Midwives, 4th ed., Ch. 2 pg. 54  4 a. Ischial tuberosity h. Levator ani b. Gluteus maximus i. Obdurator internus (cut) c. Coccyx j. Piriformis (cut and reflected) d. Bulbospongiosus k. Sacrotuberous ligament e. Ischiocavernosus l. Sacrospinous ligament f. Deep transverse perineal m. Anococcygeal ligament g. Superficial transverse perineal 7. Identify the deep pelvic floor muscles: Amber (Coad et al., 2020) Anatomy & Physiology for Midwives, 4th ed., Ch. 2 pg. 55  5 a. Pubic symphysis j. Deep transverse perineal b. External urethral sphincter k. Perineal body c. Levator hiatus l. Superficial transverse perineal d. Anterior superior iliac spine (ASIS) m. Obdurator internus (cut) e. Levator ani n. Ischial spine f. Coccygeus o. Piriformis (cut and reflected) g. Anococcygeal ligament p. Sacrospinous ligament (cut) h. Coccyx q. Sacrotuberous i. Ischiocavernosus 8. The function of the bony pelvis is to: Amber (Coad et al., 2020) Anatomy & Physiology for Midwives, Ch. 2 pg. 52 1) Support and maintains the anatomical position of the internal female reproductive organs, the bladder and intestine ​ 2) Provides voluntary muscle control for micturition and defecation as well as contributes to maintaining optimal intra-abdominal pressure 3) Involved in gait and movement ​ 4) It has an essential role in delivery and facilitates birth by resisting the descent of the fetal head and shoulders, forcing the fetus to rotate forward in the presence of strong regular contractions. 9. The ischium has three important landmarks through which the fetus must navigate and can be assessed while in labor. These are the 1) Inlet [pelvic brim], 2) pelvic cavity and 3) pelvic outlet. (Posner et al., 2023). Gabrielle, Oxorn-Foote, Ch 5, pg 38 ​  6 10. Differentiate the true pelvis from the false pelvis. (Gabrielle, Oxorn-Foote, Ch 5, pg 38) ​ The false pelvis is above the true pelvis and its function is to support the pregnant uterus. It spans from the lumbar vertebrae posteriorly, to the iliac fossae laterally and to the anterior abdominal wall anteriorly. ​ The true pelvis is below the false pelvis and below the pelvic brim. It is the bony canal that the fetus passes through during birth–divided into the 3 parts mentioned above (Posner et al., 2023). (Posner et al., 2023) 11. List and name the 6 diameters of the pelvis. Amber (Posner, G.D., 2023). Oxorn-Foote Human Labor & Birth, 7th ed., Ch 5 pg 4 1. Anteroposterior diameter 4. Right oblique diameter 2. Transverse diameter 5. Posterior sagittal diameter 3. Left oblique diameter 6. Anterior sagittal diameter 12. The A-P diameter of the inlet that extends from the middle of the sacral promontory to the posterior superior margin of the pubic symphysis and is the most important AP diameter through which the fetus must pass is the obstetric conjugate and measures approximately 11 cm in length (Posner et al., 2023). (Gabrielle, Oxorn-Foote, ch 5, pg 41). 13. The A-P diameter that extends from the middle of the sacral promontory to the subpubic angle and can be manually measured is the __diagonal___ conjugate and it  7 measures approximately _12.5 cm___ in length. (Posner et al., 2023). (Gabrielle, Oxorn-Foote, ch 5, pg 41) 14. The plane of least dimensions is the most important plane of the pelvis because it has the least room and where arrest of progress most often takes place. Amber (Posner, G.D., 2022) Oxorn-Foote Human Labor & Birth, 7th ed., Ch 5 pg 7 15. The ____transverse___(distance between the ischial spines)_____ diameter is smallest diameter through which the fetus must pass is approximately ____10____cm (King et al., 2019. (Gabrielle, Varney’s Midwifery, ch 10, pg 342) 16. List the 5 most important measurements when assessing the obstetric capacity of the pelvis. 1. Obstetric conjugate of the inlet 4. Posterior sagittal diameters of the three planes 2. Distance between the ischial spines 5. Curve and length of the sacrum 3. Subpubic angle and bituberous (Posner et al., 2023) diameter (Gabrielle, Oxorn-Foote, ch 5, pg 46-47) 17. This structure divides the false pelvis from the true pelvis: Linea terminalis– runs along the pelvic brim from the superior part of the pubic symphysis to the sacral promontory (King et al., 2019). (Gabrielle, Varney’s Midwifery, ch 10, pg 341). 18. Describe the function of the false pelvis. What are the boundaries? ​ The false pelvis is above the true pelvis and its function is to support the pregnant uterus. It spans from the lumbar vertebrae posteriorly, to the iliac fossae laterally and to the anterior abdominal wall anteriorly (Posner et al., 2023). (Gabrielle, Oxorn-Foote, Ch 5, pg 38) 19. Describe the boundaries of the following components of the true pelvis: a. Pelvic inlet: anteriorly bound by the pubic crest and spine, laterally by the iliopectineal lines on the innominate bones and posteriorly by the anterior borders of the ala and the promontory of the sacrum  8 b. Pelvic cavity (midpelvis): a curved canal. The anterior wall is straight and shallow. The posterior wall is deep and concave. Laterally are the ischium and part of the bodies of the ilium. c. Pelvic outlet: Anteriorly bound by the arcuate pubic ligament and the pubic arch. Laterally bound by the ischial tuberosity and the sacrotuberous ligament. Posteriorly bound by the tip of the sacrum (Posner et al., 2023). (Gabrielle, Oxorn-Foote, ch 5, pg 38) 20. Provide the average dimensions and significance of the following diameters of the pelvis: a. anatomic conjugate: 11.5 cm– of no obstetric significance b. obstetric conjugate (what is the average minimum measurement in cm?): 11 cm– most important anteroposterior diameter because fetus must pass through c. diagonal conjugate:12.5 cm– clinically significant because it is used to measure the obstetric conjugate (Posner et al., 2023). (Gabrielle, Oxorn-Foote, ch 5, pg 41) 21. Which is the most important AP conjugate in relation to obstetric outcome? How is it calculated? The obstetric conjugate is the most important anteroposterior diameter because it is the one through which the fetus must pass. The approximate length is calculated by subtracting 1.5 cm from the diagonal conjugate. (Posner et al., 2023). (Helen, Human Labor & Birth, Ch 5, pg 41) 22. Describe the boundaries of the “plane of least dimensions” and its significance in the birth process. The plane of least dimensions is the narrowest part of the pelvic outlet, and it is important in the birth process because it affects whether the baby can pass through the birth canal during delivery. Boundaries include: 1.​ Lower border of the pubic symphysis  9 2.​ White line on the fascia covering the obturator forminas 3.​ Ischial spines 4.​ Sacrospinous ligaments 5.​ Sacrum (Posner et al., 2023) (Helen, Human Labor & Birth, Ch 5, pg 43) 23. What is the narrowest transverse diameter of the pelvis that the fetal head must pass? The interspinous diameter is the narrowest diameter the fetal head negotiates, at 10 cm in diameter. Kasey. (Garcia, V.R., 2024). Varney’s Midwifery, 7th ed., Ch. 19, pg. 781. 24. Following is an illustration of the four basic pelvic types. Briefly describe each, if they are favorable for vaginal birth, and include their effect on labor.  10 a. Gynecoid: Sex type: normal females. Shape is round or transverse oval; transverse diameter is a little longer than the anteroposterior. Good uterine function; early and complete internal rotation; spontaneous delivery; wide public arch reduces perineal tears. Favorable for vaginal birth. b. Android: Sex type: males. Heart shaped or wedge shaped. Deep transverse arrest is common; arrest as occiput posterior position with failure of rotation; delivery is often by difficult forceps application, rotation, and extraction; the narrow pubic arch may lead to major perineal tears. Poor prognosis for vaginal birth. c. Anthropoid: Sextype: apelike. Shape is a long anteroposterior oval. Delivery and labor are usually easy; birth face to pubis is common. Favorable for vaginal birth. d. Platypelloid: Sex type: Flat female. Shape is transverse oval. Labor results in delay at inlet. Poor prognosis, due to disproportion; labor often results in a cesarean section. Unfavorable vaginal birth (Posner et al., 2023). (Helen, Human Labor & Birth, Ch 5, pgs 49-52) 25. Pelvis types are classified by the posterior component of the pelvic inlet. This is called the Caldwell Malloy Classification. It is important to note that there are rarely “pure” types, as any pelvis can have some characteristics of any type. Kasey. (Posner, G.D., 2023). Oxorn-Foote Human Labor & Birth, 7th ed., Ch. 5 pg. 47 26. The three functions of the pelvic floor are: Helps support the pelvic organs in humans, to generate effective intra abdominal pressure, the diaphragm, abdominal wall, and pelvic floor muscles must contract simultaneously, and during labor, the pelvic floor assists in anterior rotation of the presenting part and guides it forward/downward through the birth canal. Kasey. (Pascali, D.U., 2023). Oxorn-Foote Oxorn-Foote Human Labor & Birth, 7th ed. Ch. 2 pg. 22. 27. The major components of the pelvic floor and their functions are: 1) the endopelvic fascia: provides support to the vagina and the visceral organs 2) the pelvic diaphragm: separates the pelvic cavity from the perineal space. It supports the viscera, abdominal organs, and pelvic organs. 3)the perineal diaphragm: separates the internal levator muscles from the superficial perineal muscles  11 4) the superficial perineal muscle: muscles are involved in urethral support and sphincter mechanics (Phillippi et al., 2024). (Helen, Varney’s Midwifery, Ch 8, pgs 318-319) 28. The Pubococcygeus muscle of the pelvic floor lies in the midline and is perforated by the urethra, vagina, and rectum; It is the muscle that is torn with a second-degree laceration or in the case of an episiotomy cut through during birth. Kasey. (Pascali, D.U., 2023). Oxorn-Foote Oxorn-Foote Human Labor & Birth, 7th ed. Ch. 2 pg. 11. 29. Name the 3 muscles that compose the Levator ani? a. Pubococcygeus - it lies in the midline. It originates from the posterior side of the pubis and from the white line of the pelvic fascia anterior to the obturator canal. b. Iliococcygeus - muscles arise from the white line of the pelvic fascia posterior to the obturator canal. c. Ischioccygeus - originate from the ischial spines and insert into the lateral borders of the coccyx and the fifth sacral vertebra (Posner, et al., 2023). (Helen, Human Birth and Labor, Ch 2, pg 11-12) 30. This muscle’s primary function is to act as a sling for the vagina and is the primary support of the female pelvic organs: Pubovaginalis Muscle. Kasey. (Pascali, D.U., 2023). Oxorn-Foote Oxorn-Foote Human Labor & Birth, 7th ed. Ch. 2 pg. 11-12. 31. Describe the boundaries of the urogenital triangle. The urogenital triangle is bounded: 1.​ Anteriorly: by the subpubic angle 2.​ Laterally: by the ischiopubic rami and the ischial tuberosities 3.​ Posteriorly: by the transverse perineal muscle and the base of the urogenital diaphragm (Posner et al., 2023) (Helen, Human Birth & Labor, Ch 3, pgs 16- 17)  12 32. Discuss the components of urogenital triangle: It contains the following: 1.​ Opening of the vagina 2.​ Terminal part of the urethra 3.​ Crura of the clitoris with the ischiocavernosus muscles 4.​ Vestibular bulbs (erectile tissue) covered by the bulbocavernosus muscles 5.​ Bartholin’s glands and their ducts 6.​ Urogenital diaphragm 7.​ Muscles that constitute the central point of the perineum (perineal body) 8.​ Perineal pouches, superficial and deep 9.​ Blood vessels, nerves, and lymphatics (Posner, et al., 2023) (Helen, Human Birth & Labor, Ch 3, pg 17) 33. Describe the vestibule and what it contains The vestibule is the area between the labia minora that extends from the clitoris to the fourchette. It contains the openings of the urethra and vagina, as well as the openings of the greater vestibular glands and the paraurethral glands (Phillippi, et al., 2024). (Helen, Varney’s Midwifery, Ch 8, pg 322) 34. Describe the importance of the pubococcygeus muscle. Also known as the pubovisceral, the insertion of this muscle creates functional sphincters that contribute to fecal and urinary continence (Phillippi et al., 2024). (Helen, Varney’s Midwifery, Ch 8, pg 318) 35. Identify the muscles that form the perineal body and their obstetric significance. 1.​ Sphincter ani externus (external anal sphincter) 2.​ Two levator ani muscles 3.​ Superficial and deep transverse perineal muscles 4.​ Bulbocavernosus muscle (Posner et al., 2023). (Helen, Human Labor & Birth, Ch. 3, pg 20) Which muscles provide support to the perineum? The perineum is supported by several muscles, including the superficial transverse perineal muscle, the bulbocavernosus muscle, and the ischiocavernosus muscle (Phillippi et al., 2024).  13 (Helen, Varney’s Midwifery, Ch 8, pg 319) What muscles are involved in lacerations during childbirth? The muscles of the perineum, specifically the transverse perineal muscles, bulbocavernosus muscles, and depending on the severity of the tear, the external anal sphincter which controls the anus (Phillippi et al., 2024). (Helen, Varney’s Midwifery, Ch 8, pg 319) 36. The perineum, levator ani, rectal sphincter, skin of the vulva, urogenital diaphragm and lower portion of the birth canal is innervated by the pudendal nerve and its branches. This nerve originates from S2, S3, & S4 vertebrae. Kasey. (Garcia, V.R., 2024). Varney’s Midwifery, 7th ed., Ch. 8, pg. 321. 37. Blood vessels branching from the pudendal artery perfuse the perineum.Kasey. (Garcia, V.R., 2024). Varney’s Midwifery, 7th ed., Ch. 8, pg. 321. 38. Identify the bones that make up the fetal skull by completing the following diagram. Kasey. (King, T.L, & Danhausen, K.,, 2024). Varney’s Midwifery, 7th ed., Ch. 19, pg. 786-787. (Posner, G.D., 2023). Oxorn-Foote Oxorn-Foote Human Labor & Birth, 7th ed. Ch. 6 pg. 54-55. 1.​ Frontal Bone 2.​ Sagittal Suture 3.​ Parietal Bone 4.​ Posterior Fontanelle  14 5.​ Lambdoidal Suture 6.​ Occipital Bone 7.​ Temporal Bone 8.​ Coronal Suture 39. Identify sutures and fontanels of the fetal skull and their importance during birth Kasey. (Posner, G.D., 2023). Oxorn-Foote Oxorn-Foote Human Labor & Birth, 7th ed. Ch. 6 pg. 55-57. 1.​ Anterior Fontanel: Facilitates molding of the skull during birth, allowing it to pass through the birth canal more easily, Remains open well after birth, allowing for the rapid growth of the brain, Becomes ossified (closed) by around 18 months of age. 2.​ Sagittal Suture: Important for the flexibility of the skull during birth, allowing the bones to overlap and facilitate the passage through the birth canal. 3.​ Coronal Suture: Crucial for maintaining skull shape and accommodating changes during delivery and growth. 4.​ Frontal Suture: This suture also plays a role in skull flexibility during birth and accommodates the brain's early growth  15 5.​ Lambdoidal Suture: Like other sutures, they allow for cranial flexibility during childbirth. 40. Identify landmarks and diameters of the fetal skull. Label the diameters and the presentations that they correlate with (for example, label the suboccipitobregmatic diameter, which is seen in vertex presentation. What is the average length of this diameter? How does it impact vaginal birth?) Hannah (Posner, G. D., Black, A. Y., Jones, G. D., & El-Chaar, D., 2023 & Phillippi, J. & Kantrowitz-Gordon, I., 2024). Human Labor & Birth Ch. 6 pg. 58-59, Varney’s Midwifery 7th ed Ch. 19 pg. 789 Label and describe each one: 1 & A: Suboccipitobregmatic - Begins where the occipital bone meets the neck and extends to the center of the bregma. Seen when the head is well flexed. Approximately 9.5cm long. Ideal for vaginal delivery because this position allows the smallest cephalic diameter to pass through the maternal pelvis. 2 & D: Submentobregmatic - Begins at the junction of the neck/lower jaw and extends to the center of the bregma. Seen in face presentations. Approximately 9.5cm long. If there is adequate room in the maternal pelvis, the fetus can deliver this way. 3 & B: Occipitofrontal - Begins at the external occipital protuberance and extends to the glabella. Seen in military attitude. Approximately 11cm long. Considered similar clinically to a brow presentation as the diameter of this part of the head typically does not fit through the maternal pelvis. 4 & C: Verticomental - Begins at the chin and extends to the vertex of head. Seen in brow presentations. Approximately 13.5cm long. Vaginal delivery is not typically possible if brow presentation persists because this is the largest diameter of the fetal head and it typically does not fit in the maternal pelvis. 41. Why are these diameters important? Hannah (Posner, G. D., Black, A. Y., Jones, G. D., & El-Chaar, D., 2023 & Phillippi, J. & Kantrowitz-Gordon, I., 2024). Human Labor & Birth Ch. 6 pg. 59, Varney’s Midwifery 7th ed Ch. 19 pg. 789 Diameters are clinically significant for recognizing the attitude and presentation of the fetus to determine success for vaginal delivery.  16 42. Briefly define and give examples of the following: summarize lie, presentation, presenting part, attitude, denominator, and position (fetopelvic relationships). Hannah (Posner, G. D., Black, A. Y., Jones, G. D., & El-Chaar, D., 2023). Human Labor & Birth Ch. 7 pg. 66, 72 a. Lie – relationship of the long axis of the fetus to the long axis of the mother (simply put – how the baby is lying in the uterus). Two types: longitudinal lie (cephalic or breech) or transverse/oblique lie. b. Presentation – the part of the fetus that is over the inlet. Three main: cephalic (head first), breech (pelvis first), or shoulder. c. Presenting part – the part of the fetus that is nearest to the cervix and what the vaginal examiner touches first. d. Attitude – relationship of fetal parts to one another (i.e. flexion and extension) (Midwives Revision of Uganda. (2025). Fetal Attitudes. Kololo; Midwives Revision.) e. Denominator – description of the presenting part. Examples: occiput, forehead (frontum), chin (mentum), sacrum, or scapula. f. Position – relationship of denominator to the front/back/sides of maternal pelvis. An example is LOP (left occiput posterior) meaning the denominator is in the posterior segment of the pelvis and 45 degrees left of the midline. 43. What serves as a landmark for assessing descent of the fetal head? Hannah (Posner, G. D., Black, A. Y., Jones, G. D., & El-Chaar, D., 2023). Human Labor & Birth Ch. 6 pg. 56 Sutures of the skull provide landmarks to identify the position of the baby's head during vaginal examination. 44. What is the denominator for the following: Hannah (Posner, G. D., Black, A. Y., Jones, G. D., & El-Chaar, D., 2023). Human Labor & Birth Ch. 7 pg. 67 a. Cephalic presentation, flexed attitude, posterior vertex presenting part Occiput  17 b. Cephalic presentation, partial extension, brow presenting part Forehead (frontum) c. Cephalic presentation, complete extension, face presenting part Chin (mentum) d. Breech (complete) presentation, flexed hips and knees, buttocks presenting part. Sacrum 45. What is the largest transverse diameter of the fetal head? The largest AP diameter? The smallest AP diameter? Hannah (Posner, G. D., Black, A. Y., Jones, G. D., & El-Chaar, D., 2023). Human Labor & Birth Ch. 6 pg. 58-59 ​ a. What is the largest transverse diameter of the fetal head? Biparietal diameter ​ b. What is the largest anterior posterior (AP) diameter of the fetal skull? Verticomental diameter ​ c. What is the smallest diameter of the fetal skull? Bitemporal diameter is the smallest transverse diameter. The suboccipitobregmatic is the smallest AP diameter. 46. When a baby is in ROA position, what do each of these letters mean and how are they determined? Hannah (Posner, G. D., Black, A. Y., Jones, G. D., & El-Chaar, D., 2023). Human Labor & Birth Ch. 7 pg. 72 R= right (denominator is 45 degrees right of midline) O= occiput (back of the head is the denominator) A= anterior (denominator is in the anterior segment of the pelvis) 47. What would the denominator be for a breech baby? Hannah (Posner, G. D., Black, A. Y., Jones, G. D., & El-Chaar, D., 2023). Human Labor & Birth Ch. 7 pg. 67 Sacrum 48. Define the following terms: Hannah (Posner, G. D., Black, A. Y., Jones, G. D., & El-Chaar, D., 2023). Human Labor & Birth Ch. 6 pg. 57 a.​ Occiput – back of the head/occipital bone  18 b.​ Vertex – area between the two fontanelles on top of the skull c.​ Bregma – anterior fontanelle d.​ Lamda – posterior fontanelle e.​ Sinciput – aka brow; region between glabella and bregma f.​ Glabella – elevated area between orbital ridges aka brow bone area g.​ Nasion – root of the nose h.​ Parietal bosses – distance between each parietal bone; widest transverse diameter of the fetal head 49. Describe the size/shape of the fetal anterior and posterior fontanelles? Hannah (Posner, G. D., Black, A. Y., Jones, G. D., & El-Chaar, D., 2023). Human Labor & Birth Ch. 6 pg. 56-57​ Anterior fontanelle is approximately 3cm by 2cm and is diamond shaped. Posterior fontanelle is Y or triangular shaped and is much smaller than the anterior fontanelle (no size in either book that I could find).  19 References Coad, J., Dunstall, M., & Pedley, K. (2020). The reproductive and urinary systems. In Anatomy and physiology for midwives (4th ed., pp. 52–55). Elsevier. King, T. L., Brucker, M. C., Osborne, K., & Jevitt, C. (2019). Varney’s midwifery (6th ed.) Jones & Bartlett Learning. Midwives Revision of Uganda. (2025). Fetal Attitudes. Kololo; Midwives Revision. Pascali D.U. (2023). Pelvis: bones, joints, and ligaments. In Oxorn-Foote human labor & birth (7th ed., pp. 1-4). McGraw-Hill Education. Retrieved from https://obgyn-mhmedical- com.uc.idm.oclc.org/content.aspx?bookid=3238&sectionid=269576269 Phillippi, J. & Kantrowitz-Gordon, I. (2024). Varney’s midwifery (7th ed.). Jones & Bartlett Learning. Posner G.D. (2023). Obstetric pelvis. In Oxorn-Foote human labor & birth (7th ed., pp. 4-7). McGraw-Hill Education. Retrieved from https://obgyn-mhmedical-com.uc.idm.oclc.org /content.aspx?bookid=3238&sectionid=26957648 Posner, G. D., Black, A. Y., Jones, G. D., & El-Chaar, D. (2023). Oxorn-Foote human labor & birth (7th ed.) McGraw Hill.