OB Evals 2

1. MERCADO, EUNICE F. Preconceptional counseling should be sought by those: a. with pregestational diabetes mellitus b. contemplated to undergo assisted reproductive technology c. working as xerox operator d. all of the above e. A and B Answer: D. Rationale: Preconceptional counseling should address ALL RISK factors pertinent to both mother and fetus. General questions to be answered include how pregnancy will affect maternal health, and how a high-risk condition will affect the fetus. Almost any medical, obstetrical, or genetic condition warrants some consideration prior to pregnancy. Reference: Williams Obstetrics 22nd Edition p.114 2. Mendoza, Rigel Faye R. Preterm pregnancy is best defined as: A. Live birth less than 37 weeks age of gestation B. Live birth more than 20 weeks but less than 37 weeks AOG C. Delivery more than 20 weeks but less than 37 weeks AOG D. Delivery after 20 weeks AOG but before the expected date of confinement (EDC) E. Delivery after 20 weeks but before 42 weeks AOG Answer: B. Live Birth more than 20 weeks but less than 37 weeks AOG Rationale: Preterm Pregnancy is a viable pregnancy (greater than 20 weeks AOG). Preterm pregnancy runs from >20 weeks to Section II. Anatomy and Physiology > Chapter 2. Maternal Anatomy

71. Manalang, Capella The cardinal movements of labor occur continuously takes place until the completion of the second stage of labor? a) preparatory b) dilatational c) pelvic Answer: C Rationale: Downward movement of the biparietal diameter of the fetal head to within the pelvic diameter of the fetal head to within the pelvic inlet, full descent occurs and the fetal head extrudes beyond and touches the posterior vaginal wall Reference: Demelin L (1927) La Contraction Uterine et les Discinesies Correlative. Paris: Dupon 72. Patdu, Jacky A. Which of the following cardinal movements of labor continuously takes place until the completion of the second stage. a. Descent b. Flexion c. Internal rotation d. Extension Answer: A Rationale: In primiparous woman, engagement must be completed first before descent can occur. In multiparous woman, descent usually begins with engagement. Descent must then be said to be continuous until the end of labor because it is the descending action of the baby through the pelvic inlet. The completion of the second stage is defined as the expulsion of the baby. Descent is not complete until this stage because the baby is continuously descending towards being expulsed. References: William Edition 23, page 378-380, 389 77. PAO, CHRISTEL V. In occiput anterior presentation, which among the fetal part appears first during extension? a) brow b) nose c) mouth d) chin Answer: A Rationale: With progressive distension of the perineum and vaginal opening, an increasingly larger portion of the occiput gradually appears. The head is born as the occiput, bregma, forehead, nose, mouth, and finally the chin pass successively over the anterior margin of the perineum. Hence, among the choices above, the brow will appear first before the succeeding parts. Reference: Williams Obstetrics, 23rd edition, Chapter 23 74. Yaun, Pilipina Karla Mutya V. Expulsion is concerned with the delivery of what fetal part? a) head b) shoulder c) thorax

d) abdomen Answer: b. shoulder Rationale: Expulsion occurs almost immediately after external rotation, the anterior shoulder appears under the symphysis pubis, and the perineum soon becomes distended by the posterior shoulder. After delivery of the shoulder, the rest of the body quickly passes. The shoulder, since it the widest among the fetal parts that has to pass through, it is the most difficult part to be expelled. After expulsion of the shoulder, we can ensure that the rest of the body will quickly pass since they have smaller breadth. Source: William’s Obstetrics, 23rd edition: Normal Labor and Delivery, pages 59-61 and 380 75. MELISSA KATE D. MENDOZA As the fetal head engages, the sagittal suture commonly lies: a) Midway between the symphysis pubis and promontory b) Nearer the symphysis pubis c) Nearer the promontory d) Along the oblique diameter Answer: A. Midway between the symphysis pubis and promontory Rationale: Asynclitism- Although the fetal head tends to accommodate to the transverse axis of the pelvic inlet, the sagittal suture, while remaining parallel to that axis, may not lie exactly midway between the symphysis and the sacral promontory. The sagittal suture frequently is deflected either posteriorly toward the promontory or anteriorly toward the symphysis. Such lateral deflection to a more anterior or posterior position in the pelvis is called asynclitism. If the sagittal suture approaches the sacral promontory, more of the anterior parietal bone presents itself to the examining fingers, and the condition is called anterior asynclitism. If, however, the sagittal suture lies close to the symphysis, more of the posterior parietal bone will present, and the condition is called posterior asynclitism. With extreme posterior asynclitism, the posterior ear may be easily palpated. Moderate degrees of asynclitism are the rule in normal labor. However, if severe, the condition is a common reason for cephalopelvic disproportion even with an otherwise normal-sized pelvis. Successive shifting from posterior to anterior asynclitism aids descent. Reference: William’s Obstetrics, 23rd Edition, page 379 76. RAGASA, JOHN R. In determining the station of the fetal head, which of the following fetal and maternal landmark relationship is correct? a) biparietal diameter – ischial spines b) biparietal diameter – pelvic inlet c) presenting part – ischial spines d) presenting part – pelvic inlet Answer: C Rationale: The station of the presenting fetal part in the birth canal is describe in relationsip to the ischial spines, ahich are halfway between the pelvic inlet and the pelvic outlet. When the lowermost portion of the presenting fetal part is at the level of the spines, it is designated as being at 0 station. Each fifth represents a centimeter above or below the spines. (-) if towards the spines and (+) if it passes the spines. Reference: Williams Obstetrics 23rd Edition, p. 392. 77. MATABUENA, MAIKA ALMINA F. Which among the following cardinal movements of labor requires the resistance of the pelvic a. descent b. internal rotation c. extension d. expulsion Answer: C

Rationale: Because one of the two forces come into play during extension is the force supplied by the resistant pelvic floor that acts anteriorly, while the other one is the force exerted by the uterus which acts more posteriorly. Reference: Williams Obstetrics, 22nd ed.(2005) page 233 78. Rojas, Bianca B. Which of the following cardinal movements may take place even before the onset of labor in a primipara? a. engagement b. descent c. flexion d. internal rotaion Answer: ENGAGEMENT. Rationale: The mechanism by which the biparietal diameter, the greatest transverse diameter of the fetal head in occiput presentations, passes through the pelvic inlet is designated engagement. The fetal head may engage during the last few weeks of pregnancy or not until after the commencement of labor. In many multiparous and some nulliparous women, the fetal head is freely movable above the pelvic inlet at the onset of labor. In nulliparas, engagement may take place before the onset of labor, and further descent may not follow until the onset of the second stage. In multiparous women, descent usually begins with engagement. Reference: Williams, 22ndedition, SECTION IV - LABOR AND DELIVERY, Chapter 17 Normal Labor and Delivery, page 413 79. Sadang Ronaldo B. Restitution occurs during what cardinal movement of Labor a) Extention b) descent c) internal rotation d) EXTERNAL ROTATION ANSWER: D RATIONALE: External rotation OR restitution refers to return of the fetal head to the correct anatomic position in reference to the fetal torso. When the fetal head is free of resistance, it untwists about 45o left or right returning to its anatomic position Reference: Sumpaico, 3rd edition, page 400 80. ORPILLA, MARK JASON G. Engagement is determined by what Leopolds Maneuver? a) I b) II c) III d) IV Answer: D. IV Rationale: THIRD MANEUVER. Using the thumb and fingers of one hand, the lower portion of the maternal abdomen is grasped just above the symphysis pubis. If the presenting part is not engaged, a movable mass will be felt, usually the head. The differentiation between head and breech is made as in the first maneuver. If the presenting part is deeply engaged, however, the findings from this maneuver are simply indicative that the lower fetal pole is in the pelvis, and details are then defined by the last (fourth) maneuver. FOURTH MANEUVER. The examiner faces the mother's feet and, with the tips of the first three fingers of each hand, exerts deep pressure in the direction of the axis of the pelvic inlet. In many instances, when the head has descended into the pelvis, the anterior shoulder may be differentiated readily by the third maneuver. Reference: Williams 22nd Edition Page 231 via Ebook 81. NABONG, MARCO PAULO C.

The purpose of external rotation is to bring the _________ diameter of the fetus along the anteroposterior diameter of the pelvic outlet. a. bisacromial b. bitemporal c. biparietal d. mentooccipital Answer: A Rationale: External Rotation. The delivered head next undergoes restitution. Restitution of the head to the oblique position is followed by a completion of external rotation to the transverse position, a movement that corresponds to rotation of the fetal body, serving to bring its bisacromial diameter into relation with the anteroposterior diameter of the pelvic outlet. Reference: Williams Obstetrics 22nd edition. Chapter 17 Normal Labor and Delivery. pp417 82. Maebritt Wincent M. Tibubos When the cervix becomes fully dilated with the presenting part in LOT, station +2, what cardinal movement should take place next? a) Flexion b) Internal rotation c) Extension d) External rotation Answer: The most probable answer is letter C. extension. Rationalization: The end of internal rotation occurs when the sharply flexed head reaches the pelvic floor which is most likely in station +1 or +2. Therefore, the next cardinal movement is extension. Reference: Chapter 17. Normal Labor and Delivery. Section 4 page 380 William’s Obstetrics 23 rd Edition. 83. Desiree Joy Anne M. Timtiman A parturient arrives at the emergency room with a bulging perineum and anterior fontanel palpable over the posterior rim of the vaginal opening. What cardinal movement of the labor is taking place? a) Internal rotation b) Extension c) restitution d) expulsion Answer: b. extension. Rationale: Since in restitution and extension the fetus head is already out of the vagina then it is impossible to palpate for the anterior fontanel inside the vaginal opening. As define by Williams, internal rotation ends when the head reaches the pelvic floor and extension begins when the head reaches the vulva until the face of the fetus is seen. Hence the extension is most probably the cardinal movement taking place in this patient. Reference: Chapter 17. Normal Labor and Delivery section 4 page 380 William’s Obstetrics 23 rd Edition. 84. Villoso, Aaron Christian Earl I. The straightening and extension of the fetal body during a uterine contraction promotes which mechanism of labor? a. flexion c. descent b. internal rotation d. Extension – caused by force exerted by the uterus, which acts more posteriorly, and the second, supplied by the resistant pelvic floor and the symphysis, which acts more anteriorly. The resultant vector is in the direction of the vulvar opening, thereby causing head extension Answer: C. DESCENT Rationale: Descent is brought about by one or more of four forces: (1) pressure of the amnionic fluid, (2) direct pressure of the fundus upon the breech with contractions, (3) bearing-down efforts of maternal abdominal muscles, and (4) extension and straightening of the fetal body. Reference: Williams Obstetrics 23rd edition, page 380

85. TEE, JAN RAEMON The sagittal suture is noted to be deflected towards the symphysis pubis. What bone is palpable during vaginal examination? A. posterior parietal B. anterior parietal C. frontal D. Occipital ANSWER: A RATIONALE: "the sagittal suture lies close to the symphysis, more of the posterior parietal bone will present, and the condition is called posterior asynclitism" REFERENCE: William's 23rd edition, Chapter 17: Normal Labor and Delivery 86. YUSINGBO, Iami Rio Patricia A. During the second stage of labor, the presenting part is noted to be directly behind the symphysis pubis. What cardinal movement has taken place? a. Flexion b. Internal Rotation c. Descent d. Extension ANSWER: B. Internal Rotation Rationale: This movement consists of a turning of the head in such a manner that the occiput gradually moves toward the symphysis pubis anteriorly from its original position or less commonly, posteriorly toward the hollow of the sacrum. Internal rotation is essential for the completion of labor, except when the fetus is unusually small. Flexion - As soon as the descending head meets resistance, whether from the cervix, walls of the pelvis, or pelvic floor, then flexion of the head normally results. In this movement, the chin is brought into more intimate contact with the fetal thorax, and the appreciably shorter suboccipitobregmatic diameter is substituted for the longer occipitofrontal diameter. The suboccipitobregmatic diameter, the shortest anteroposterior diameter of the fetal head, is passing through the pelvic inlet in this cardinal movement. Descent - This movement is the first requisite for birth of the newborn. In nulliparas, engagement may take place before the onset of labor, and further descent may not follow until the onset of the second stage. In multiparous women, descent usually begins with engagement. Descent is brought about by one or more of four forces: (1) pressure of the amnionic fluid, (2) direct pressure of the fundus upon the breech with contractions, (3) bearingdown efforts of maternal abdominal muscles, and (4) extension and straightening of the fetal body. Extension - After internal rotation, the sharply flexed head reaches the vulva and undergoes extension. If the sharply flexed head, on reaching the pelvic floor, did not extend but was driven farther downward, it would impinge on the posterior portion of the perineum and would eventually be forced through the tissues of the perineum. When the head presses upon the pelvic floor, however, two forces come into play. The first force, exerted by the uterus, acts more posteriorly, and the second, supplied by the resistant pelvic floor and the symphysis, acts more anteriorly. The resultant vector is in the direction of the vulvar opening, thereby causing head extension. This brings the base of the occiput into direct contact with the inferior margin of the symphysis pubis. Reference: William’s Obstetrics. 23rd edition e-book. Chapter 17 - Normal Labor & Delivery. (No page number indicated in the ebook) 87. ROMERO, KRISTINE JOY V. A Primigravid is admitted on her 8 th hour of her labor with the following findings on vaginal examination: cervix is 4-5cms dilated both fontanels are palpated easily, station 0. Which of the cardinal movements of labor has taken place? a) Engagement b) Descent c) Flexion d) Internal Rotation

Answer: A Rationale: Because at Station 0 it means that the presenting part of the fetus is now in a level of below the pelvic inlet which means the pelvis inlet is adequate for the fetal head. Reference: Williams Obstetrics 22nd edition Section II Chapter 2 88. Pena, Abigail R. What is the significance of the findings on the station of the presenting part? a. fetal head is small b. pelvic inlet is adequate c. vaginal delivery is highly anticipated d. fetal membranes are likely to rupture early Answer: B Rationale: The mechanism by which the biparietal diameter- greatest transverse diameter in an occiput presentation passess through the pelvic inlet is designated engagement. In Station 0, fetal head is at the level of the ischial spine, therefore the head is engaged and pelvic inlet is adequate. Reference: Williams Obstetrics, 23rd edition page: 378 89. ORAA, MIKHAIL JOREX B. th On the 12 hour of labor, the cervix is dilated to 8-9 cms. The triangular fontanel is palpated easily but not the diamond shaped fontanel. What cardinal movement of labor has taken place? a. Descent b. Flexion c. Internal Rotation d. Extension Answer: B Rationale: Flexion. In this movement, the chin is brought into more intimate contact with the fetal thorax, and the appreciably shorter suboccipitobregmatic diameter is substituted for the longer occipitofrontal diameter. Triangular fontanel is synonymous to the posterior fontanel w/c is the presenting part after flexion has taken place in an occiput posterior position. nd Reference: Williams Obstetrics 22 edition. Chapter 17 Normal Labor and Delivery. page 417 90. OLIVA, MARK MOSES D. One hour after the cervix becomes fully dilated, the presenting part remains in LOT. What cardinal movement of labor failed to take place? a. descent c. internal rotation b. flexion d. extension Answer: C. internal rotation Rationale: In phase 3 of parturition where the cervix is fully dilated, of about 10 cm allows the passage of presenting fetal part and it marks the first stage of labor, the stage of cervical effacement and dilatation. In internal rotation which is essential in completion of labor, the fetus starts to descend in LOT, in some instances when the fetus is unusually small, the presenting part fails to express from Left Occiput Transverse(LOT) to Occiput Anterior(OA) thus Internal rotation doesn’t take place and the presenting fetal part remains in Left Occiput Transverse(LOT). Reference: Williams Obstetrics, Twenty-Third Edition (ebook), Chapter 6 and Chapter 17 http://www.brooksidepress.org/Products/Obstetric_and_Newborn_Care_1/lesson_10_Section_1A.htm 91. OMAPAS, SHEILA Animal studies have shown an adverse effect and there are no adequate and well controlled studies done on pregnant women. a. Category A

b. Category B c. Category C d. Category D e. Category X Answer: C Rationale: Explained almost verbatim in Williams Reference: Williams, 23rd edition, page 315, table 14-3. 92. Montillano, Ana Cristina N. Adequate and well controlled studies have not shown an increased risk of abnormalities Answer: Category A Rationale: According to the guidelines released by the US Food and Drug Administration, Category A drugs have not shown to increase the risk of abnormalities in all the trimesters of pregnancy. Source: William’s Obstetrics 23rd edition page 315 93. MACATANGAY, MIKHAILJON SAMUEL C. Studies that are adequate well controlled and observational in pregnant women or animals have shown fetal abnormalities a) Category A b) Category B c) Category C d) Category D e) Category X Answer: E Rationale: CATEGORY X - this medication is contraindicated who are or may become pregnant. It may cause fetal harm. If is drug is used during pregnancy or if a woman becomes pregnant while taking this medication, she should be appraised of potential hazard to the fetus. There are few medication in this medication in this category that have never been shown to cause fetal harm but should be avoided nonetheless such as the rubella vaccine. Reference: Williams 23rd Edition page 315 Table 14-3 94. Siocon, Mariel L. No adequate and well controlled studies have been conducted in pregnant women and animals. a. Category A b. Category B c. Category C d. Category D e. Category X Answer: C Rationale: Food and Drug Administration Categories for Drugs and Medications Category A: Studies in pregnant women have not shown an increased risk for fetal abnormalities if administered during. Category B: Animal reproduction studies have been performed and have revealed no evidence of impaired fertility or harm to the fetus. Animal studies have shown an adverse effect, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus during the first trimester of pregnancy, and there is no evidence of a risk in later trimesters. Category C: Animal reproduction studies have shown that this medication is teratogenic (or embryocidal or has other adverse effect), and there are no adequate and well-controlled studies in pregnant women There are no animal reproduction studies and no adequate and well-controlled studies in humans.

Category D: This medication can cause fetal harm when administered to a pregnant woman. If this drug is used during pregnancy or if a woman becomes pregnant while taking this medication, she should be apprised of the potential hazard to the fetus. This category also contains medications used to treat potentially life-threatening medical conditions. Category X: This medication is contraindicated in women who are or may become pregnant. It may cause fetal harm. Reference: Page 315, table 14-3, Williams Obstetrics 23rd edition. 95. MACALINTAL, KATRINA CYRIL M. Animal studies have shown an adverse effect, but adequate and controlled studies on pregnant women have not shown risk to the fetus. A. Category A B. Category B C. Category C D. Category D E. Category X Answer: B Rationale: Table 14-3. Food and Drug Administration Categories for Drugs and Medications Category A: Studies in pregnant women have not shown an increased risk for fetal abnormalities if administered during the first (second, third, or all) trimester(s) of pregnancy, and the possibility of fetal harm appears remote. Fewer than 1 percent of all medications are in this category. Examples include levothyroxine, potassium supplementation, and prenatal vitamins, when taken at recommended doses. Category B: Animal reproduction studies have been performed and have revealed no evidence of impaired fertility or harm to the fetus. Prescribing information should specify kind of animal and how dose compares with human dose. or Animal studies have shown an adverse effect, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus during the first trimester of pregnancy, and there is no evidence of a risk in later trimesters. Examples include many antibiotics, such as penicillins, macrolides, and most cephalosporins. Category C: Animal reproduction studies have shown that this medication is teratogenic (or embryocidal or has other adverse effect), and there are no adequate and well-controlled studies in pregnant women. Prescribing information should specify kind of animal and how dose compares with human dose. or There are no animal reproduction studies and no adequate and well-controlled studies in humans. Approximately two thirds of all medications are in this category. It contains medications commonly used to treat potentially life-threatening medical conditions, such as albuterol for asthma, zidovudine and lamivudine for human immunodeficiency viral infection, and many antihypertensives, including blockers and calcium-channel blockers. Category D: This medication can cause fetal harm when administered to a pregnant woman. If this drug is used during pregnancy or if a woman becomes pregnant while taking this medication, she should be apprised of the potential hazard to the fetus. This category also contains medications used to treat potentially life-threatening medical conditions, for example: systemic corticosteroids, azathioprine, phenytoin, carbamazepine, valproic acid, and lithium. Category X: This medication is contraindicated in women who are or may become pregnant. It may cause fetal harm. If this drug is used during pregnancy or if a woman becomes pregnant while taking this medication, she should be apprised of the potential hazard to the fetus. There are a few medications in this category that have never been shown to cause fetal harm but should be avoided nonetheless such as the rubella vaccine. Reference: Williams Obstetrics, 23rd edition, Table 14-3 96. PURIFICACION, ARMIN JR. O N.R had missed her period for the first time and she decided to seek consult with an OB-Gyn where an internal

examination revealed a soft and closed cervix A. Phase 1 (ANSWER) B. Phase 2 C. Phase 3 D. Phase 4 ANSWER: A RATIONALE: Phase 1 of Parturition is exemplified by Uterine Quiescene and Cervical Softening. According to William's, "Thus, the first stage of this remodeling—termed softening—is characterized by an increase in tissue compliance, yet the cervix remains firm and unyielding. Hegar (1895) first described palpable softening of the lower uterine segment at 4 to 6 weeks' gestation, and this sign was once used to diagnose pregnancy." Thus the cervix becomes softer than in the non-pregnant state, "In nonpregnant women, the cervix is closed and firm, and its consistency is similar to nasal cartilage.", however remains closed as the cervix is not yet ready to dilate. Reference: E-Book Version of Williams 23rd Edition Copyright © The McGraw-Hill Companies. All rights reserved. Williams Obstetrics, 23e > Chapter 6. Parturition > 97. Reyes, Christian Lawrence L. A.B. experienced labor pains of eight hours duration. She consulted at the ER and examination revealed a five cm cervical dilatation fully effaced, cephalic presentation and intact membranes. i. Phase I - period of uterine quiescence and cervical softening j. Phase 2 – uterine awekening and activation, cervical ripening k. Phase 3 – progressive dilation and effacement of the cervix to delivery of the fetus l. Phase 4 - involution and repair of the uterus Answer: C Rationale: Reference:

98. Noche, Rizza Joyce C. What is the significance of the findings on the station of the presenting part? a) The fetal head is small b) The pelvic inlet is adequate c) Vaginal delivery is highly anticipated d) Fetal membranes are likely to rupture early Answer: b. the pelvic inlet is adequate. Rationale: The level or station is the relationship of the fetal presenting part to the ischial spines, halfway between the pelvic inlet and outlet. When the lowermost portion of the presenting part is at the level of the ischial spines, it is designated as 0. If presenting part is at station 0 or below, it is most often considered as engaged because the biparietal plane has passed through the pelvic inlet. The significance of the findings is the Bishop scoring. Assessed and tabulated are the 5 characteristics namely: Cervical dilatation, Effacement, Consistency, Position & Fetal station, used to predict labor induction outcome. American College of Obstetrics and Gynecology classification of stations dividing the pelvis above and below the spines into fifths with intervals of approximately 1 cm. From the pelvic inlet toward the ischial spines, designated as -5 to -1 then below the spines, +1 to +5, corresponding to its visibility at the introitus. (Williams, p.392) *Bishop Scoring System for Assessment of Inducibility (Williams, p. 502) Score Dilatation Effacement Station Cervical Cervical position consistency 0 Closed 0 – 30 % -3 Firm Posterior 1 1 to 2 cm 40 – 50 % -2 Medium Midposition 2 3 to 4 cm 60 – 70 % -1 Soft Anterior 3 ≥ 5 cm ≥ 80 % + 1, + 2 ----Reference: (Williams, p.392)

99. ROY, JAMES MAXIMILLIAN V D.W. is currently breastfeeding and is seeking opinion regarding family planning. a. Phase 1 b. Phase 2 c. Phase 3 d. Phase 4 Answer: D Rationale: Phase 4 of parturition includes the parturient’s recovery, uterine involution, cervical repair and breastfeeding which occurs after the delivery of conceptus and before the restoration of the woman’s fertility. rd Reference: Williams 23 Edition (E-Book), Chapter 6, Phases of Parturition, Figure 6-1 100. VILLASENOR, MARICE V L.L. is at the Labor Room she has reached full cervical dilatation and the nurse is preparing her for vaginal delivery a. Phase 1 b. Phase 2 c. Phase 3 d. Phase 4 Answer: C Rationale: Phase 3 is summarized in 3 clinical stages. The first stage begins when widely spaced uterine contractions of sufficient frequency, intensity, and duration are attained to bring about cervical thinning, termed effacement. This labor stage ends when the cervix is fully dilated—about 10 cm—to allow passage of the fetal head. The first stage of labor, therefore, is the stage of cervical effacement and dilatation The second stage begins when cervical dilatation is complete, and ends with delivery. Thus, the second stage of labor is the stage of fetal expulsion The third stage begins immediately after delivery of the fetus and ends with the delivery of the placenta. Thus, the third stage of labor is the stage of placental separation and expulsion. rd Reference: Williams 23 Edition (E-Book), Chapter 6, Phases of Parturition, Figure 6-1