A. Obstetric

1. What is the job of the false pelvis?

The false pelvis lies superior to the true pelvis and linea terminalis. It is a larger and wider basin that supports the enlarged during pregnancy, as well as the intestines.

2. Name the 3 parts of the true pelvis.

The three parts of the true pelvis are the inlet, the , and the .

3. What are the 4 classifications of the pelvis?

The four classifications of the pelvis are the gynecoid, the android, the anthropoid, and the platypelloid.

4. Concerning the above types of , what effect does each have on: labor, engagement of the fetal head, and overall birth prognosis?

The gynecoid pelvis during labor reduces perineal tears during labor, and contributes to spontaneous delivery. The uterus functions well, reducing in size when it’s supposed to. The fetus also successfully rotates throughout the birth canal early, and completely. The fetal head will engage in the transverse or oblique diameter, meaning the back of the head will face the lateral or diagonal sides of the pelvis such as the pectineal or arcuate line. With the head engaged in these starting positions, the fetus will also be in a slight asynclitism, meaning the fetus’ head will be tipped towards one shoulder, with its body and head not going in a completely straight line downwards. The fetus has good flexion, with his chin tucked in his chest and is in the common occiput anterior position, where the back of his head is facing down and toward the pubic symphysis. The gynecoid often results in a good prognosis.

Android pelvises result in a poor overall birth prognosis. During labor there’s an increase in major perineal tears. Most commonly, the fetus will engage in a deep transverse arrest, or in an occiput posterior position with no continued rotation. The back of the fetal head will face the in this position. It is a difficult delivery with the use of forceps to rotate and extract the baby. The fetal head is in a transverse or posterior diameter in asynclitism as well. There is extreme modeling done on the head.

The anthropoid pelvis during labor and delivery is usually easy, with the fetal face commonly facing the . The fetus engages in an anteroposterior or oblique position, which explains the occiput posterior position during delivery. This pelvis has a good overall prognosis.

Finally, the platypelloid has a very poor overall birth prognosis, which is usually ending in cesarean section. During labor there is a delay at the inlet of the pelvis, which is just the start. The fetus also engages in a transverse diameter with marked asynclitism.

5. What are the reasons for these differences? Explain for each type of pelvis why there are differences in labor, engagement, and prognosis for birth.

The gynecoid pelvis is a normal female pelvis, which is 50% of women have. There is a smaller amount of perineal tears due to the wide in the gynecoid pelvis, allowing for a wider area already “stretched” that prevents tearing. Due to its round and wide false pelvis, the uterus is heavily supported during its largest moment to perform good uterine function during birth. The inlet of the pelvis, has a well rounded forepelvis in the anterior segment, and a broad, deep and roomy posterior segment. These two segments allow for a large, roomy space to have good initial engagement at the inlet. The sacrum having a deep curve, short length, and sloping backwards helps the fetus internally rotate midway through the pelvis, due to the larger amount of space. The ischial spines are not prominent, and the sidewalls of the pelvis are parallel and straight which allow for an easy descent with no parts too narrow to get stuck in. The iliopectineal line of the pelvis is average, reducing the amount of passage the fetus needs to travel. Finally, the outlet has a short inferior pubic rami, adequate capacity, and a long anteroposterior diameter which will give more space for the fetal head to birth in an occiput posterior or anterior (more common) position, compared to transverse.

The android pelvis on the other hand is shaped more like a males pelvis. It is in the shape of a heart of wedge, with a very short and inadequate posterior sagittal diameter at the inlet. The posterior segment also is shallow, and the sacral promontory indents protrude into the inlet, reducing the space. Also, the anterior segment and forepelvis is narrow, and sharply angulated. Because of this, the fetal head engages transversely or posteriorly, ending with a deep transverse arrest. In the midpelvis, all the diameters are reduced, decreasing the movement capability of the fetus. This makes it very difficult for the fetus to rotate internally, causing the use of forceps. The sacrum is flat, inclined forward, long, narrow, and heavy. The sidewalls are convergent and are the shape of a funnel, while the ischial spines are prominent. The depth of the pelvis is long. All of these factors in the midpelvis reduce the capacity, and make it uncomfortable for both the mother and the baby during labor. The sacrum and sidewalls with these features especially will inhibit the descent of the baby. At the outlet, the narrow and deep pubic arch will increase major perineal tears. The transverse diameter at the outlet is narrow while the anteroposterior diameter is very short, continuing to reduce the birth canal making it harder for the birth of the fetus, This is when forceps would be used.

The anthropoid pelvis is very apelike and resembles the gynecoid pelvis the most. Starting at the inlet, it’s an oval shape, so it has a long anteroposterior, anterior sagittal, and posterior sagittal diameter. Most of the pelvis is longer and deeper than the gynecoid, but not wide. Due to this, the fetus engages in the anteroposterior or oblique position but not transverse because it is not wide enough. The midpelvis becomes more adequate like the gynecoid, with a long anteroposterior diameter. It has a narrow, long, and backwardly inclined sacrum. The sidewalls are straight, the depth is long, with an adequate capacity. The outlet of the pelvis again has a long anteroposterior diameter, normal transverse diameter, and normal or a bit narrow of a pubic arch. I believe the fetus’s face to pubis is due to the longer anteroposterior diameters throughout the entire pelvis, allowing for a roomier place for the fetus’s head/face to guide through. The prognosis is good like the gynecoid pelvis because of its oval shape allowing the fetus to engage the occiput anterior or posterior position.

The platypelloid is very rare, and the most complicated pelvis during birth. It is considered to have a transverse oral shape and the inlet of the pelvis contains a short anteroposterior diameter, while having a long transverse diameter. The posterior sagittal diameter is very short like the android pelvis, as well as the anterior sagittal diameter, unlike the android. Which I believe is what makes engagement more difficult to achieve than the android pelvis. In the midpelvis, the anteroposterior diameter is shortened, making a tighter space for the fetal head to stay engaged or to rotate and engage into an occiput anterior or posterior position. Instead, the transverse diameter is wider, allowing more room and comfort for the fetus to position itself transversely, but even then, there is delay at the inlet already before this point. The inlet of the platypelloid is shaped like a kidney and makes it extremely difficult to engage the fetal head. Although, the outlet is more favorable for birth, and if the fetal head were to engage, there could be a possibility of the fetus passing the rest of the birth canal smoothly.

B. The Fetus

1. What are fetal sutures? List the main fetal sutures.

Fetal sutures are the spaces between the of the skull that are made up of membranes. They are soft fibrous tissues that link the bones. The main fetal sutures are: sagittal suture, lambdoidal sutures (“last” sutures), coronal sutures (“cornea” sutures in the front like the eyes), frontal sutures.

2. Name the two important aspects of the sutures.

The two most important aspects of the fetal sutures are that they enable molding of the fetal head, and they are used to identify fetal positioning. During labor, fetal molding allows the bones to overlap under pressure while the fetal head is being compressed throughout the pelvis. It also allows for the brain to expand and grow as the baby develops. During a vaginal exam, understanding the fetal sutures will help the midwife diagnose the fetal head position within the pelvis.

3. What are fontanelles?

Fontanelles are soft membrane-filled spaces that are seperated from the bones by the fetal sutures. They are covered with a tough, fibrous membrane.

4. What are the two main purposes of the fontanelles?

Like the fetal sutures, the fontanelles also contribute to diagnosing the position of the fetus in the pelvis. On the other hand, the anterior fontanelle bregma is evaluated to determine the condition of the baby after birth. For instance, if the baby is dehydrated, the anterior fontanelle will be depressed and sinking below the surface of the skull. If the fontanelle is bulging, tense, and raised above the level of the skull, this means there is an increase in intracranial pressure.

5. Name the two fontanelles.

The two fontanelles are the anterior fontanelle, and the posterior fontanelle.

6. What are the 8 landmarks of the fetal skull?

The 8 landmarks of the fetal skull from back to front are: the occiput, the posterior fontanelle, the vertex, the anterior fontanelle, the sinciput, the glabella, the nasion, and the parietal bosses.

The occiput is the occipital in the back of the head where the occipital lobe resides. It is inferior and posterior to the posterior fontanelle and lambdoid sutures.

The vertex is the top and middle of the skull where the parietal bones and sagittal sutures are. It is the area between the two main fontanelles, and is bounded laterally by the parietal bosses. Sinciput (brow) is the area surrounded by the anterior fontanelle and coronal sutures superiorly. The glabella and orbital ridges are below this. It is basically the anterior region of the skull.

The glabella is the area a bit over the orbital ridges, and the nasion is the root of the nose. The parietal bosses are the sides of the parietal bones and the distance between them make up the widest transverse diameter of the fetal head.

7. Define “molding” of the fetal skull.

Molding is the ability of the fetal skull bones to maneuver over, under, or past each other in order for the fetal head to change shape and easily travel through the pelvis and birth canal. This is a very ingenious design and is capable due to the softness of the bones. The space between the edges of the bones exist to allow the movement needed as pressure is exerted on the head by the pelvis. The fetal bones are loosely joined by membranes and can move apart or come closer together. The actual volume of the skull is not reduced, because compression in one direction leads to the expansion of another. The presenting diameter of the head is what will alter in shape.

8. What is Caput Succedaneum? How does it occur?

Caput succedaneum is an area of localized swelling and serosanguineous fluid (bloody-watery fluid) collection on the head of the newborn baby during a vaginal birth. Specifically located in the connective tissues right inferior to the scalp, and superior to the periosteum. It is caused by compression and pressure exerted on the fetus’s scalp as it passes through the cervix. The cervical ring applies pressure to the fetal head, obstructing the fetal veins and preventing blood from returning to the body which swells the portion of the scalp within the cervix.

9. What is a cephalohematoma? What are some of the main reasons this occurs?

A cephalohematoma is a hemorrhage under the periosteum (deep blanket of tissue that covers the skull). It is a more traumatic injury and is caused by multiple things such as damage from the use of forceps or vacuum, prolonged pressure of the head against the cervix, manual rotation of the head, and rapid compression and relaxation of the forces/contractions on the fetal head. During a normal spontaneous delivery, this may also occur.

10. Compare and contrast the differences between a cephalohematoma and caput.

The caput succedaneum is a collection of fluid and is generally at the vertex of the head. It is not associated with further complications and is more superficial than the cephalohematoma. Generally, the swelling will reduce and go away on its own within 1-2 days, but in other rare cases it can lead to bruising of the skin over the swollen area, resulting in scarring or hair loss. The caput also can cross over the suture lines. It is largest at birth and will immediately begin to shrink until it disappears a few hours or days later.

Unlike the caput succedaneum, the cephalohematoma can continue to grow after birth and take a much longer amount of time to resolve. It is a collection of blood, not fluid. It can take days to even months before healing, and they most commonly occur on the parietal bones. Due to cephalohematoma being deeper in the fetal head, they most likely are due to a greater trauma, and result is further complications. For instance, about 5% of them lead to skull fracture, anemia, and infection. Cephalohematomas can not cross suture lines due to it being under the periosteum. The blood clots are at the edges, while the center contains fluid. The hemorrhage may not appear for several hours after the birth. It grows larger over time and is fixed in a certain site of the skull.

11. How are the two issues above different from a Subgaleal Hematoma?

A subgaleal hematoma is a much more severe and extensive injury that is more commonly seen as a result of the traction due to a vacuum-assisted vaginal delivery. Instead, it bleeds deeper between the galea aponeurosis of the scalp and the periosteum of the skull. This will also result in a skull fracture or intracranial hemorrhage, at a much higher rate than 5% of the cephalohematoma and should be evaluated for. It will develop 12 to 72 hours after delivery. It is diagnosed by superficial skin bruising and a boggy visible mass over the scalp. Subgaleal hematomas can spread across the entire head, crossing suture lines. A lot of blood can accumulate in this hematoma, and if it does, there is a visible fluid wave that can be seen, and the baby may need a blood transfusion. The baby requires close observation, and will be monitored for hyperbilirubinemia.

12. What is a meningocele? What should you look for in diagnosing this?

A meningocele is a hernia that protrudes from the meninges. A hernia is an abnormal exit of tissue or organs, and the meninges are the three membranes that envelope the brain and spinal cord. This is a serious congenital deformity. When diagnosing this, it should be assessed to see if it lies over a suture or fontanelle. If so, it is a meningocele. Also, it will become tense when the baby cries.

C. Fetopelvic Relationships

1. When determining where the fetus is in relationship to the pelvis different words are used. One of these is “Lie”. What is Lie and what are the two markers of Lie? How can you tell which it is?

Lie refers to the relationship of the long axis (length) of the fetus to the long axis of the mother. There are two lies: longitudinal, and transverse or oblique. A longitudinal lie is when the long axis of the fetus and mother are parallel, while the transverse is when the long axis of the fetus is perpendicular to the mother, basically lying sideways or horizontal. Oblique is when the long axis of the fetus is oblique or diagonal to the long axis of the mother. The mother in the standing position is the base used to refer to the directional terms. Anterior, posterior, left and right are the mother’s front, back, left and right side.

2. Presentation is another marker of the fetal/pelvic relationship. What is a cephalic presentation?

Cephalic presentation is when the presenting part of the fetus is the fetal head and it is considered “head first.” It is preferred over the breech or transverse presentation. The fetus begins to get into this position between the 32nd and 36th weeks.

3. What are the four major cephalic presentations (also called “attitude”)? Describe each.

An attitude represents the relationship of fetal parts to each other. There are two basic attitudes: flexion and extension. When the chin is near the chest, this is flexion. When the occiput is closer and closer towards the back of the baby, this is called extension. The most common fetal attitude is flexion, with the arms and legs folded and tucked in front of the body, and the back slightly curved forward. The four major cephalic presentations are: flexion (vertex), military (median vertex), brow, and face.

Flexion (vertex) is the most desirable cephalic presentation of all. It is when the baby’s chin is tucked in his chest. The posterior portion of the vertex, or back of the head, is the presenting part of the baby.

Military or median vertex, is when the two main fontanelles, the anterior and posterior, are the presenting part of the baby. The baby is seen as facing straight ahead, with neither flexion or extension.

The brow presentation is a halfway extension, and the forehead or brow bone is the presenting part of the baby. Finally, the face or extension is when the face is presenting.

4. When speaking of breech presentations, what are the different types?

There are four different types of breech presentations. They are a complete breech, frank breech, footling breech, and kneeling breech. Complete breech is when the bum is the presenting part of the baby, and there is flexion at both the hips and knees. Frank breech is when the baby's legs are extended straight up and are parallel to his body with his hips flexed. Here, the bum also is presenting. Footling breech is when one leg is flexed, and one leg is extended straight down, with this leg being the presenting part, called a single footling. Sometimes both feet are extended downward and this makes it a double. Kneeling breech is when the hips and knees are both extended, with the knees facing downwards being the presenting part of the baby. It can be a single or double kneeling breech.

5. What does it mean to have a transverse or oblique lie?

When the long axis of the fetus is perpendicular or oblique to the long axis of the mother, this represents the transverse and oblique lie. Transverse basically means the fetus is lying horizontally in the womb, while oblique means lying diagonally.

6. When the vertex is the presenting part, what are the 8 possible positions?

The eight possible positions when the vertex is the presenting part are:

1. Occiput Anterior (OA) 2. Left Occiput Anterior (LOA) 3. Left Occiput Transverse (LOT) 4. Left Occiput Posterior (LOP) 5. Occiput Posterior (OP) 6. Right Occiput Posterior (ROP) 7. Right Occiput Transverse (ROT) 8. Right Occiput Anterior (ROA)

7. What is lightning? What are the symptoms?

Lightening is the feeling a woman experiences towards the end of pregnancy, when the baby engages in the pelvis before birth. It is called lightening because as the baby descends from under the mother’s rib cage, she can more easily expand her ribs to draw deeper breaths and eat heavier amounts. This brings the mother a sense of relief. In 65 % first time mothers, lightening occurs two weeks before labor. The fetus will drop into the lower part of the uterus. One other good symptom is decreased epigastric pressure. This can bring some uncomfortable symptoms along with the sense of relief such as: increased pressure in the pelvis, lower backache, frequent urination, constipation, hemorrhoids, swelling of the legs and feet, feeling like the child is lower or is about to fall out, and difficulty walking.

8. What does the word “gravidity” mean/ What are the possible types and what do they stand for?

Gravidity is the state or condition of pregnancy. A gravida is known as a pregnant woman. When describing a woman’s gravidity, we mention her total number of pregnancies regardless of their duration. There are three types of gravidas: primigravida, secundigravida, and multigravida. Primigravida is a woman's first pregnancy. Secundigravida is a woman's second pregnancy. Multigravida is a woman who's been pregnant several times. This can also be interchangeably used at times to describe a woman who has given birth at least one time.

9. What does “parity” mean? What are some words used to describe parity along with their meaning?

Parity refers to the amount of past viable pregnancies that have been delivered. This number does not increase due to the amount of children born. One successful pregnancy and delivery of twins is still one parity. A para refers to past viable and successful pregnancies. There are four types of para’s: nullipara, primipara, multipara, and parturient. Nullipara is who has never been pregnant or has been pregnant but never delivered a baby who reached viability. A primipara is a woman who is pregnant with her first baby, but it also refers to a woman who's birthed one pregnancy, whether the baby was alive or dead. A multipara is often described as a woman who is delivering her second child. A parturient is a woman in labor.

10. Explain the GTPAL system and give a few examples.

GTPAL stands for gravidity, term deliveries, preterm deliveries, abortions, and living children. It is an acronym that describes the mothers obstetrical situation, and pregnancy outcomes.

Gravidity is the number of times a woman has been pregnant. Term deliveries is the number of babies in those pregnancies that were born (alive or stillborn) at 37 weeks gestation and onward (multiples are counted as one). Preterm deliveries is the number of babies in those pregnancies that were born (alive or stillborn) between 20 and 37 weeks (multiples are counted one). Abortion is the number of babys in those pregnancies who were terminated or miscarried before 20 weeks. Living children is the number of children living (multiples are counted individually) A few examples are:

1. A 34 year old patient is currently pregnant. She has three other children with two of them being a set of twins. She has also had one abortion. Her GTPAL is G=4, T=2, P-0, A=1, L=3. 2. A 24 year old female had a miscarriage at 9 weeks gestation. She is currently pregnant with triplets. She also has a 4 year old son who was born at 35 weeks gestation, and a 2 year old daughter who was born at 39 weeks gestation. G=4 T=1 P=1 A=1 L=2 3. A 38 year old female is currently pregnant with twins. She has had 3 miscarriages, one at 8 weeks, one at 13 weeks, and another at 7 weeks. She has one daughter who is 6 years old and was born at 31 weeks gestation. She also had a stillborn baby at 25 weeks gestation. G=6 T=0 P=2 A=3 L=1

D. Engagement, Synclitism, and Asynclitism

1. Define Engagement. What is dipping?

Engagement is the act of the widest part of the fetal head (biparietal diameter) or bum (intertrochanteric diameter) descending through and past the inlet and officially engaging in the pelvis. Dipping is when the presenting part of the fetus (head or buttocks) passed through the inlet, but did not yet engage.

2. Define Station. How is Station measured?

Between the ischial spines there is an imaginary line drawn to represent the relationship between it and the presenting part of the fetus, a measurement known as the station of the fetus. It measures how far the baby has descended in the pelvis. The indicators for the station are measured as 5 centimeters above the line, and 5 centimeters below it. The location of the ischial spines indicates a station of 0. So, when the bony part of the presenting skull in a cephalic presentation, or the buttocks in a breech is at the ischial spines, it is at a 0, which is exactly in the middle of the range. Above the spines is a station of -1 or -2, all the way up to a -5. The more negative the number, the higher up towards the inlet of the pelvis the baby is. A -5 indicates the baby is at the inlet. Below the spines commences positive numbers, hence +1, +2, etc. until around +5 which is near the ischial tuberosities and the baby is at the outlet of the pelvis.

3. Define Synclitism and Asynclitism. What are the two types of Asynclitism?

Synclitism is when the widest part of the fetal head (biparietal diameter) is parallel to the planes of the pelvis. On the other hand, asynclitism is when the biparietal diameter is not parallel to the planes, but oblique to the inlet instead. There are two types of asynclitism: posterior and anterior asynclitism.

Posterior asynclitism is when the sagittal suture lies closer to the pubic symphysis than the sacrum. The posterior parietal bone will be the presenting part during a vaginal examination, being lower than the anterior parietal bone. Of course, the parietal bones are not posterior or anterior to each other, they are the side bones of the skulls. But, when speaking anatomically with respect to the mother, the lower bone presenting is towards the back being posterior. The baby's face is facing towards the sacrum. Posterior synclitism is a more common mechanism than synclitism and anterior asynclitism in normal women. Anterior asynclitism is when the anterior parietal bone presents, and the sagittal suture is closer to the sacrum. The baby's face is facing towards the pubis.

4. When does engagement typically occur?

In primigravidas, engagement usually occurs 2-3 weeks before labor begins. In multiparas, engagement may occur during any point of labor, before or after it has begun. It occurs when the sagittal suture of the fetal head is in the transverse diameter of the maternal pelvis, resulting in a cephalic transverse presentation. This is the most common position at engagement, specifically the left occiput transverse. Engagement is when the biparietal diameter has passed the inlet. ​ ​ 5. If you were charting a mother’s progress in labor you would list engagement, synclitic or asynclitic factors, and the station. Give two examples of how this would be written.

1. Vaginal exam determines fetal biparietal diameter is past the resulting in engagement, and vertex of the fetal head is at station 0. Also reveals a posterior asynclitic position after feeling the presenting posterior parietal bone, and the sagittal suture closer to the pubic symphysis. 2. Vaginal exam determines the absence of engagement, and the fetus is dipping. The anterior parietal bone was felt as the presenting part, and the sagittal suture line is closer to the sacrum. The fetus is at a -2 station.