Core Curriculum for Maternal- Newborn Nursing Fourth Edition Edited by: Susan Mattson, RNC-OB, CTN, PhD, FAAN

Core Curriculum for Maternal- Newborn Nursing This page intentionally left blank Core Curriculum for Maternal- Newborn Nursing Fourth Edition Edited by: Susan Mattson, RNC-OB, CTN, PhD, FAAN Professor Emerita College of Nursing and Healthcare Innovation Arizona State University Tempe, Arizona Judy E. Smith, PhD, RNC-WHNP Professor School of Nursing California State University—Long Beach Long Beach, California 3251 Riverport Lane Saint Louis, MO 63043 CORE CURRICULUM FOR MATERNAL-NEWBORN NURSING ISBN: 978-1-4377-1576-7 Copyright © 2011 by Association of Women’s Health, Obstetric and Neonatal Nurses. Published by Saunders, an imprint of Elsevier Inc. All rights reserved. Copyright © 2004, 2000, 1993 by Saunders, an imprint of Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permissions may be sought directly from Elsevier’s Rights Department: phone: (+1) (US) or (+44) (UK); fax: (+44) ; e-mail: . You may also complete your request on-line via the Elsevier website at Library of Congress Cataloging-in-Publication Data Core curriculum for maternal-newborn nursing/edited by Susan Mattson, Judy E. Smith. – 4th ed. p. ; cm. Includes bibliographical references and index. ISBN 978-1-4377-1576-7 (hardcover : alk. paper) 1. Maternity nursing—Outlines, syllabi, etc. 2. Nursing—Study and teaching—Outlines, syllabi, etc. I. Mattson, Susan. II. Smith, Judy E. [DNLM: 1. Maternal-Child Nursing—Outlines. 2. Curriculum—Outlines. WY 18.2 C7965 2011] RG951.N33 2011 618.2’0231—dc22 Executive Editor: Robin Carter Managing Editor: Laurie K. Gower Publishing Services Manager: Jeff Patterson Project Manager: Jeanne Genz Design Direction: Charlie Seibel Printed in the United States of America Last digit is the print number: 9 8 7 6 5 4 3 2 Linda Bond, PhD, RNC Professor Emerita, Kirkhof College of Nursing Grand Valley State University Allendale, Michigan Beverly Bowers, PhD, RN, CNS Associate Professor, College of Nursing University of Oklahoma Health Sciences Center Oklahoma City, Oklahoma Linda Callahan, CRNA, PhD Professor, School of Nursing California State University—Long Beach Long Beach, California Natalie Diane Cheffer, PhD, RN, CPNP Associate Professor, Department of Nursing California State University—Long Beach Long Beach, California Catherine R. Coverston, PhD, RNC Associate Professor, College of Nursing Brigham Young University Provo, Utah Dustine Dix, RN, MSN Clinical Assistant Professor, School of Nursing University of North Carolina—Chapel Hill Chapel Hill, North Carolina Makeba B. Felton, RN, MSN, FNPC, WHNP Clinical Assistant Professor College of Nursing and Healthcare Innovation Arizona State University Phoenix, Arizona S. Kim Genovese, PhD, MSN, MSA, RN-BC Executive Director, Nursing 2000 North, Inc. La Porte, Indiana Elizabeth Gilbert, RNC, MS, FNP-BC, CNS Director of Professional Practice Banner Thunderbird Medical Center Glendale, Arizona Whitney Hardy, RN, BS Staff Nurse, Neonatal Intensive Care Unit CJW Medical Center, Chippenham Campus Richmond, Virginia Denise G. Link, PhD, WHNP, CNE, FNAP Associate Dean, Clinical Practice and Community Partnerships College of Nursing and Healthcare Innovation Arizona State University Phoenix, Arizona Susan Mattson, RNC-OB, CTN, PhD, FAAN Professor Emerita College of Nursing and Healthcare Innovation Arizona State University Phoenix, Arizona Jacqueline M. McGrath, PhD, RN, FNAP, FAAN Associate Professor, School of Nursing Department of Family and Community Health Virginia Commonwealth University Richmond, Virginia v vi CONTRIBUTORS Barbara A. Moran, PhD, CNM, FACCE Assistant Professor, School of Nursing The Catholic University of America Washington, DC Susan Saffer Orr, PT, PCS, IBCLC Lactation Consultant Torrance Memorial Medical Center Torrance, California; Columbia Pediatrics Long Beach, California Debra Ann Rannalli, RN, MSN, CPNP Lecturer California State University—Long Beach Long Beach, California Children’s Hospital—Los Angeles Los Angeles, California Kathryn Records, PhD, RN Associate Professor Core Director, Research Mentoring and Collaboration College of Nursing and Healthcare Innovation Arizona State University Phoenix, Arizona Mary Ann Rhode, RN, MS, CNM Clinical Practice Coordinator Exempla Certified Nurse-Midwives Exempla Saint Joseph Hospital Denver, Colorado Charlotte Stephenson, RN, DSN, CLNC Clinical Professor, Nelda C. Stark College of Nursing Texas Woman’s University Houston, Texas Judy E. Smith, PhD, RNC-WHNP Professor, Department of Nursing California State University—Long Beach Long Beach, California Keiko L. Torgersen, BSN, MS, RNC Perinatal Educator MatSu Regional Medical Center Palmer, Alaska Gail M. Turley, MSN, RNC-OB, NEA-BC Administrative Director, Nursing Services Crozer-Chester Medical Center Upland, Pennsylvania Lucy R. Van Otterloo, RNC, MSN Assistant Professor, Department of Nursing California State University—Long Beach Long Beach, California Connie Sampson von Köhler, RNC-OB, MSN, C-EFM, CPHQ Clinical Nursing Instructor Long Beach Memorial Medical Center/ Miller Children’s Hospital Adjunct Faculty, School of Nursing California State University—Long Beach Long Beach, California Tamara Whitmer, MS, NPD, RN-BC Clinical Educator, Women’s Center Banner Desert Medical Center Mesa, Arizona Margaret Yancy, RN, MS, WHNP, ANP-C Clinical Associate Professor Advanced Practice Nursing of Adults in Primary Care College of Nursing and Healthcare Innovation Arizona State University Phoenix, Arizona Beverly Bowers, PhD, RN, CNS Associate Professor, College of Nursing University of Oklahoma Health Sciences Center Oklahoma City, Oklahoma Kathleen Haubrich, PhD, RN Associate Professor, Department of Nursing Miami University—Hamilton Campus Hamilton, Ohio Janet Massoglia, BSN, MSN, FNP Instructor, Department of Nursing Delta College University Center, Michigan Administrator, VA Health Care Saginaw, Michigan Barbara Pascoe, RN, BA, MA Director, The Family Place Concord Hospital Concord, New Hampshire Danielle Patrick, MSN, RN, WHCNP OB/GYN Nurse Practitioner Today’s Women’s Health Specialists Chandler, Arizona JoAnne M. Pearce, RNC, MS, FNP-C ADRN Instructor, College of Technology Idaho State University Pocatello, Idaho Elizabeth J.W. Scott, RN, MSN Lead Clinical Development Specialist Erlanger Health System Chattanooga, Tennessee Charlotte Stephenson, RN, DSN, CLNC Clinical Professor, Nelda C. Stark College of Nursing Texas Woman’s University Houston, Texas Sandra L. Walker, PhD, RN Instructor, ADN Program Southwest Georgia Technical College Thomasville, Georgia Sarah E. Whitaker, DNS, RN Program Director, Nursing Dona Ana Community College at New Mexico State University Las Cruces, New Mexico vii This book is intended to be used by practicing nurses for several purposes. First, it can be a study guide for those wishing to sit for certification examinations in maternal-newborn nursing. Basic and complex information is presented and accompanied by an extensive reference list to augment the knowledge base. Second, the text may be used by development personnel and educators as an orientation for new staff, a source of information for nurses entering or returning to maternal-newborn nursing, and a reference for nurses on those units. Third, this book can be a classroom text, particularly for students requiring a resource or reference. It is not designed to be a primary text for undergraduate students, but it could be a resource for those graduate students in women’s health nurse practitioner programs who want to review some of the material relating to pregnancy that will be needed for their practice. This edition has several significant changes that should make the book more usable for a wider audience yet keep the content directed toward the original audience. We carried forward the changes regarding complications of the newborn from the 3rd edition, in that most of the content is integrated into those chapters dealing with maternal complications, with reference to how the condition affects the fetus or neonate. This will make it easier for the maternal-newborn or LDR nurse to identify the high-risk infant and the care required until the baby stabilizes or can be transferred (if necessary). Theoretical information about the continued care of high- risk neonates with selected conditions has also been reconfigured into one chapter titled “The Newborn at Risk.” The information is included to provide a basis from which the maternal- newborn nurse may give answers to parents’ questions and provide anticipatory guidance to new parents of sick neonates. A change for the 4th edition has been the deletion of nursing diagnoses as a basis for interventions. It became apparent that using that approach led to repetitiveness in each chap- ter. Additionally, certain terminology fits more appropriately in some settings than in others and can be used to express the needs of a partic- ular client at that time. Core curriculum for acute care maternity nursing did not seem to be one of those settings in most cases. The new format of the book is one of assessment/clinical practice and interventions, with continued use of a sec- tion for health education, and the case studies and questions. We hope this text will be helpful to those of you using it for all purposes. Its editing contin- ues to be an educational and a character-building experience for us both. Susan Mattson Judy E. Smith viii We would like to acknowledge the contributors to the previous edition: Linda Bond, PhD, RNC Physiology of Pregnancy Linda Callahan, CRNA, PhD Genetics Fetal and Placental Development and Functioning Surgery in Pregnancy Natalie Diane Cheffer, RN, CPNP, PhD Adaptation to Extrauterine Life and Immediate Nursing Care Newborn Biologic/Behavioral Characteristics and Psychosocial Adaptations Diana E. Clokey, MS, RD, RPh, CDE Endocrine and Metabolic Disorders Catherine R. Coverston, PhD, RNC Psychology of Pregnancy Sandra L. Gardner, RN, MS, CNS, PNP Ethics Elizabeth Gilbert, RNC, MS, CFNP Labor and Delivery at Risk Starre Haney, RN, MS, TNCC-I, ENPC Trauma in Pregnancy Patricia Grant Higgins, PhD, RN, BSHEd, BSN, MN Postpartum Complications Marcia Liden Jasper, BSN, MS, RNC Antepartum Fetal Assessment Denise G. Link, RNC, DNSc Reproductive Anatomy, Physiology, and the Menstrual Cycle Family Planning Susan Mattson, PhD, RNC-OB, CTN, FAAN Ethnocultural Considerations in the Childbearing Period Intimate Partner Violence Jacqueline M. McGrath, PhD, RN, NNP, CCNS Identification of the Sick Newborn Barbara A. Moran, MS, MPH, CNM Maternal Infections Substance Abuse in Pregnancy Susan Saffer Orr, PT, CLC, IBCLC Breastfeeding Judith H. Poole, PhD, BSN, BA, MN Hypertensive Disorders in Pregnancy Hemorrhagic Disorders Margaret A. Putman, RN, MS, NNP Risks Associated with Gestational Age and Birth Weight Debra Ann Rannalli, RN, PNP, MSN Newborn Biologic/Behavioral Characteristics and Psychosocial Adaptations Janet Scoggin, PhD, CNM Physical and Psychologic Changes Judy E. Smith, PhD, RNC-WHNP Age-Related Changes Kathleen V. Smith, RNC, BSN, MSN Normal Childbirth ix x ACKNOWLEDGMENTS Keiko L. Torgersen, BSN, MS, RNC Intrapartum Fetal Assessment Gail M. Turley, RNC, MSN, CNAA Essential Forces and Factors in Labor Cheryl Wallerstedt, MS, RNC, IBLCE, FACCE Endocrine and Metabolic Disorders Roxena Wotring, RN, MS Environmental Hazards Margaret Yancy, RN, MS, WHNP, ANP-C Other Medical Complications SECTION ONE REPRODUCTION: FETAL AND PLACENTAL DEVELOPMENT, 1 1 Reproductive Anatomy, Physiology, and the Menstrual Cycle, 3 DENISE G. LINK 2 Genetics, 20 LINDA CALLAHAN 3 Fetal and Placental Development and Functioning, 35 LINDA CALLAHAN SECTION TWO NORMAL PREgNANCY, 59 4 Ethnocultural Considerations in the Childbearing Period, 61 SUSAN MATTSON Appendix 4-1 Quick Reference Guide to Ethnocultural Differences, 75 5 Physiology of Pregnancy, 80 LINDA BOND 6 Psychology of Pregnancy, 101 CATHERINE R. COVERSTON SECTION THREE 9 Environmental Hazards, 163 BEVERLY BOWERS SECTION FOUR INTRAPARTUM PERIOD, 189 10 Essential Forces and Factors in Labor, 191 GAIL M. TURLEY 11 Normal Childbirth, 225 MAKEBA B. FELTON 12 Intrapartum Fetal Assessment, 248 KEIKO L. TORGERSEN SECTION FIVE POsTPARTUM PERIOD, 299 13 Physical and Psychologic Changes, 301 TAMARA WHITMER 14 Breastfeeding, 315 SUSAN SAFFER ORR 15 Contraception, 335 DENISE G. LINK SECTION SIX THE NEWBORN, 343 JACQUELINE M. MCGRATH AND xii CONTENTS SECTION SEVEN COMPLICATIONs OF CHILDBEARINg, 415 18 Intimate Partner Violence, 417 KATHRYN RECORDS 19 Hypertensive Disorders in Pregnancy, 432 DUSTINE DIX 20 Maternal Infections, 449 BARBARA A. MORAN 21 Hemorrhagic Disorders, 478 S. KIM GENOVESE 22 Endocrine and Metabolic Disorders, 500 LUCY R. VAN OTTERLOO 23 Trauma in Pregnancy, 535 LUCY R. VAN OTTERLOO 24 Surgery in Pregnancy, 556 LINDA CALLAHAN 25 Substance Abuse in Pregnancy, 573 BARBARA A. MORAN 26 Other Medical Complications, 587 MARGARET YANCY 27 Labor and Delivery at Risk, 624 ELIZABETH GILBERT 28 Postpartum Complications, 650 MARY ANN RHODE SECTION EIGHT ETHICs AND IssUEs, 667 29 Ethics, 669 CHARLOTTE STEPHENSON Core Curriculum for Maternal- Newborn Nursing SECTION ONE REPRODUCTION: FETAL AND PLACENTAL DEVELOPMENT CHAPTER 1 Reproductive Anatomy, Physiology, and the Menstrual Cycle Denise G. Link OBJECTIVES 1. Identify and locate the female organs of reproduction. 2. Describe the physiologic functioning of the female reproductive system. 3. Identify the parameters of sexual maturation and menstruation, including cycle interval, duration of menstrual flow, and perimenopause. 4. Describe the physiologic changes in the ovaries, uterus, and cervix that occur during the menstrual cycle. 5. Explain the physiologic pathways of the hypothalamic-pituitary-ovarian axis and their relationship to the normal menstrual cycle. 6. Describe variations in anatomy that affect reproduction. 7. Describe variations in physiology that affect reproduction. 8. Identify the common variations in the menstrual cycle. 9. Analyze the data from a reproductive history and physical examination to determine overt and covert anatomic and physiologic factors that could affect pregnancy. 10. Prepare a set of nursing interventions for teaching pertinent concepts of anatomy and physiology to clients. INTRODUCTION Female Organs of Reproduction A. External genitalia: Vulva (Figure 1-1) 1. Mons pubis (or mons veneris) a. A rounded pad of subcutaneous fatty tissue over the symphysis pubis; covered with pubic hair b. Function is the protection of the symphysis pubis during intercourse. 2. Labia majora a. Two rounded folds of fatty and connective tissues, covered with pubic hair, that extend from the mons pubis to the perineum b. Function is the protection of the vaginal introitus. 3. Labia minora a. Narrow folds of hairless skin located within the labia majora; begin beneath the clitoris and extend to the fourchette. b. Highly vascular and rich in nerve supply; glands lubricate the vulva c. Function is erotic; swell in response to stimulation and are highly sensitive. 4. Prepuce of clitoris is a hoodlike covering over the clitoris. 5. Clitoris a. An erectile organ located beneath the pubic arch that consists of shaft and glans b. Secretes smegma, a pheromone (olfactory erotic stimulant) c. Extremely sensitive to touch, pressure, and temperature d. Function is sexual stimulation. 3 FIGURE 1-1 ■ Female external genitals. 6. Vestibule a. An oval-shaped area whose boundaries are the clitoris, fourchette, and labia minora; contains the following: (1) Urethral meatus (a) The terminal portion of the urethra, with puckered or slit appearance (b) Located 2.5 cm (1 inch) below the clitoris (2) Skene’s glands (a) Located inside the urethral meatus (b) Produce mucus for lubrication (3) Hymen (a) Tough, elastic, perforated, mucosa-covered tissue that forms a rim around the internal perimeter of the vaginal introitus (b) Hymenal opening might be absent or small, impeding menstrual flow and intercourse. (c) Characteristics of the hymen vary widely among women; the presence or absence of the hymen can neither confirm nor rule out sexual experience. (4) Bartholin’s glands (a) Located at the base of each of the labia minora, just inside the vaginal orifice (b) During coitus, secrete mucus that creates a favorable environment for sperm 7. Fourchette is a point located midline below the vaginal opening where the labia majora and labia minora merge. 8. Perineum a. Skin-covered muscular tissue located between the vaginal opening and the anus b. The area of a midline episiotomy c. Might be lacerated during childbirth. B. Internal organs (Figure 1-2) 1. Vagina a. A hollow tubular structure located behind the bladder and in front of the rectum; extends from the introitus to the cervix b. Thin-walled; composed of smooth muscle; capable of great distention as well as collapse c. Lined with a glandular mucous membrane that is arranged in folds called rugae Ovarian vessels Fallopian tube Ovarian ligament Fundus of uterus Fallopian tube Suspensory ligament Fimbria Ovarian ligament Ovary Uterine blood vessels Broad ligament Round ligament of uterus Vaginal fornix Vagina Body of uterus Isthmus Internal os Cervical canal External os Cervix Round ligament of uterus FIGURE 1-2 ■ Female reproductive organs. Front uterine wall has been removed so that the fallopian tube, uterus, cervical canal, and vagina are seen as a continuous channel. (From Langley, L.L., Telford, I.R., & Christensen, J.B. [1980]. Dynamic anatomy and physiology. New York: McGraw-Hill.) d. Highly vascular and relatively insensitive; adds little sensation for the female during coitus e. Functions as the outflow track for menstrual fluid and for vaginal and cervical secretions, the birth canal, and the organ for coitus 2. Uterus a. Located behind the symphysis pubis between the bladder and the rectum b. Muscular, hollow, smooth, mobile, nontender, firm, and symmetric c. In a woman who has not been pregnant, uterine size ranges from 5.5 to 8 cm (2.2 to 3.2 inches) long, 3.5 to 4 cm (1.4 to 1.6 inches) wide, and 2 to 2.5 cm (0.8 to 1 inch) deep; size increases after childbirth. d. Is similar in shape to a light bulb or pear e. Is a single organ composed of four distinct areas: (1) Fundus (a) The upper, rounded portion above the insertion of the fallopian tubes (b) Beginning at the 20th week of pregnancy, uterine size is measured in centimeters from the height of the fundus to the top of the symphysis pubis. (2) Corpus (or body) is the main portion of the uterus, located between the cervix and the fundus. (3) Isthmus (a) Also called the lower uterine segment during pregnancy (b) Joins the corpus to the cervix (4) Cervix (or opening of the uterus) (a) Divided into two portions: the portion above the site of attachment of the cervix to the vaginal vault is called the supravaginal portion; the portion below the attachment site that protrudes into the vagina is called the vaginal portion. (b) Composed of fibrous connective tissue (c) Diameter varies from 2 to 5 cm (0.8 to 2 inches), depending on childbearing history. (d) Length is usually 2.5 to 3 cm (1 to 1.2 inches) in a nonpregnant woman. (e) Vaginal portion is smooth, firm, and doughnut shaped, with visible central opening called the external os. (f) Internal os is the opening of the cervix inside the uterine cavity. (g) Cervical canal forms the passageway between the external os of the cervix and the uterine cavity; major feature is the ability to stretch to a diameter large enough to allow passage of an infant’s head and then to return to a closed position. (h) Produces mucus in response to cyclic hormones; thickened cervical mucus can impede the passage of sperm and bacteria; thin cervical mucus facilitates the movement of sperm and prolongs sperm life; observation of changes in cervical mucus is important in fertility awareness methods of family planning. (i) At maturity the cervical vaginal surface is covered with squamous epithelium; cervical canal is lined with columnar epithelium. [i] Area where two types of epithelium meet is called the squamocolumnar (SC) junction; also called the transformation zone or T-zone. [ii] Prior to puberty, the cervix is covered with columnar epithelium, and the SC junction is located on the outer surface of the cervix. [iii] Beginning at puberty, under the influence of estrogen, the SC junction gradually recedes back toward the external os, with squamous epithelium replacing the columnar epithelium. [iv] The SC junction is the most frequent site of changes associated with the devel- opment of cervical cancer; cells from the SC junction and other areas of the cervix are assessed via the Papanicolaou (Pap) test. f. Uterine position (Figure 1-3) (1) Five positions are possible (a) Anteflexed (b) Anterior (anteverted) (c) Midposition (d) Posterior (retroverted) (e) Retroflexed g. Uterine support (see Figure 1-2) (1) Anterior ligament extends from the anterior cervix to the bladder. (2) Cardinal (transverse) ligaments (a) Portion of the broad ligaments (b) Contain uterine blood vessels and ureters (c) Connected to the lateral margins of the uterus (3) Posterior ligament extends from the posterior cervix to the rectum. (4) Uterosacral ligaments (a) Extend from the cervix over the rectum to the sacral vertebrae (b) Maintain traction on the cervix to hold the uterus in position h. Uterine wall (1) Composed of three layers (a) Endometrium is a highly vascular mucous membrane that responds to hormone stimulation first by hypertrophy and then by secretion to prepare to receive the developing ovum; sloughs if pregnancy does not occur, resulting in menstruation; if pregnancy occurs, sloughs after delivery. (b) Myometrium is composed of smooth muscle in layers. FIGURE 1-3 ■ Uterine positions. [i] Outer layer is composed of longitudinal fibers, which predominate in the fundus and provide power to expel the fetus. [ii] Middle layer is composed of fibers interlaced with blood vessels in a figure- eight pattern; contraction following childbirth helps control blood loss. [iii] Inner layer is composed of circular fibers concentrated around the internal cervical os; provides sphincter action to help keep the cervix closed during pregnancy. (c) Parietal peritoneum covers most of the uterus, except for the cervix and a portion of the anterior corpus. 3. Fallopian tubes or oviducts (see Figure 1-2) a. Attached to the uterine fundus and curve around each ovary b. Provide a passageway for the ovum into the uterus c. 10 cm (4 inches) in length and 0.6 cm (0.25 inch) in diameter d. Composed of four parts (1) Infundibulum: the most distal portion; funnel-shaped; covered with fimbriae that guide the ovum into the tube by creating a wavelike motion (2) Ampulla: next most distal portion of the fallopian tube and site of fertilization (3) Isthmus: narrowed part of the fallopian tube; closest to the uterus (4) Interstitial: narrowest portion, which passes through the uterine myometrium and opens into the uterine cavity e. Functions (1) Capture of the ovum (2) Transport of the ovum into the uterus via peristaltic activity and wavelike motion of the cilia that line the fallopian tube (3) Secretion of nutrients to support the ovum during transport 4. Ovaries (female gonads) (see Figure 1-2) a. Comparable with the testes in the male b. Located on either side of the uterus, below and behind the fimbriated ends of the oviducts c. Supported by the ovarian ligaments and the mesovarian portion of the broad ligament d. Similar to shelled almonds in size and shape; smooth, mobile, slightly tender, and firm e. Functions include ovulation and production of hormones (estrogen, progesterone, and androgens). C. Support for organs of reproduction 1. Circulation a. Blood is supplied to the pelvis by arteries branching from the hypogastric artery (which branches from the iliac artery, a division of the aorta). b. Major pelvic arteries include the uterine, vaginal, pudendal, and perineal arteries. c. Ovarian arteries branch directly from the aorta. d. Lymphatic drainage is accomplished from the uterus, ovaries, and fallopian tubes to nodes around the aorta, with some use of the femoral, iliac, and hypogastric nodes. 2. Pelvic floor and perineum a. Functions (1) Support of the suspended internal organs of reproduction (2) Support for sphincter control, allowing for expansion of the vagina with expulsion of the fetus, and closure of the vagina after delivery b. Pelvic diaphragm (Figure 1-4) (1) Levator ani muscles (a) Puborectalis (b) Iliococcygeus (c) Pubococcygeus (2) Coccygeal muscles c. Urogenital diaphragm (see Figure 1-4): transverse perineal muscles d. Perineum (see Figure 1-4) (1) Bulbocavernosus muscle (2) Ischiocavernosus muscle (3) Anal sphincter muscle (4) Perineal strength can be increased through pelvic floor (Kegel) exercises.