OBGYN 1 Final Review

What are the different cysts that appear on an ovary throughout the menstrual cycle? (Be able to identify them on a sonogram or diagram)

*Nabothian cysts:* cervical cysts that are dilated retention cysts from intermittent blockage of an endocervical gland (usually regarded as simply physiological/normal)

What is pathogomonic?

A sign or symptom that is so characteristic of a disease that it can be used to make a diagnosis. For example, Koplik spots in the mouth opposite the first and second upper molars are pathognomonic of measles.

Femur length

Femur length Measure along the osseous portion of the shaft. measure only the diaphysis (bony portion)

Fetal head (head cirfumerence)

Fetal head (at the same level as the BPD) Head Circumference- measurement is taken at the same level as the BPD. HC = BPD + OFD divided by 2, times Pi (3.14) or HC = BPD + OFD times 1.57

What is fimbrae and villi? How are they different?

Fimbrae finger-like projections that accept the egg from the ovary to the fallopian tubes Villi hair-like or thread-like projections of trophoblastic cells and fetal blood vessels)

Basic ovarian phases:

Follicular stage: days 1-14; occurs BEFORE ovulation; its the production and release of estrogen by developing follicles that causes endometrium lining to regenerate Luteal stage: day 14-28; occurs AFTER ovulation, corpus luteum develops and progesterone is produced

1. What is HCG? 2. What are the values for visualization sonographically of an early gestation? 3. How do the values relate to pregnancy?

HCG is a hormone which is detectable in the maternal serum or urine approximately 8-10 days after ovulation and is indicative of pregnancy. Evidence of an intrauterine pregnancy in the form of a gestational sac should be sonographically visualized transabdominally when the serum HCG level reaches **1800 mIU/ml (Second International Standard {2nd IS}), or 3,600 mIU/ml First International Reference Preparation or Third International Reference Preparation. With transvaginal scanning, the discriminatory zone is about 800 to 1000 mIU (2nd IS) or 1000 to *2000 (IRP), when a 2 to 3 mm gestational sac; For the first 8 weeks HCG levels should DOUBLE every 2 days.

Which muscles form the floor of the pelvis?

The levator ani muscles, the coccygeus, and the perineum make up the pelvic floor.

What are OOD and IOD? (Be able to identify them on a sonogram.)

The outer orbital distance (OOD) or binocular distance includes both of the fetal orbits at the same time, the interorbital distance (IOD) or interocular distanc emeasures the distance between the two orbits. The outer orbital distance or binocular distance is taken from outer border to outer border (the transverse distance between the lateral walls of the orbits).

What is the double bleb sign?

The sonographic presentation of the amnion and yolk sac.

1. How are the lateral ventricles measured and where are they located? 2. What is their relation to the choroid plexus?

The widest diameter of the atrium is measured through the choroid plexus, and normal measurement should not exceed 10 mm. (usually measures around 6.5 mm). In addition, the distance between the medial wall of the lateral ventricle and the medial margin of the choroid plexus should be less than 5 mm at the level of the atrium.

What is tubovarian complex and tubovarian abscess?

Tubo-ovarian abscess (TOA): If the pus spills out from the fimbriated opening of the tube, it may involve the ovary (oophoritis) as well as the tube, and may create an abscess called a tubo-ovarian abscess. When the pus gets into the peritoneal cavity, a pelvic peritonitis develops. Abscess formation in the peritoneum may cause adhesions to form between the uterus, bladder, adnexa and bowel, "fixing" these structures to each other (the ovaries and tubes are difficult to distinguish sonographically.) *Tubo-ovarian complex is an infection where the ovaries and tubes are involved, but the tube and ovary can still be distinguished. *

Piriformis muscle ultrasound

(*Remember, this is the muscle most often mistaken for ovaries. The way to check is to turn on it and see if it extends like a muscle.) Sonographically, this muscle mass is identified best on transverse scans. It returns a low-level reflection.

retroflexed ultrasound image

(the uterus is folded on itself backwards)

How are the uterus, vagina, and tubes formed?

*The Mullerian Duct System is a pair of embryonic ducts that develop into the upper portion of the vagina uterus, and uterine tubes in the female*. *The lower part develops from the urogenital sinus*

1. What is a zygote and how is it formed? 2. What does a zygote become?

1. (also called fecundated ovum) when the oocyte and spermatozoon fuse. A zygote is the single cell that forms after sperm fertilizes an egg cell. A zygote is a diploid cell, formed from the union of two haploid cells. 2. becomes blastomeres --> morula (solid)--> blastocyst (hollow) (which has an inner and outer cell mass; inncer cell mass becomes embryo, cord, amnion, and secondary yolk sac, yolk sac; outer cell mass becomes trophpblasts --> then eventually becomes the embryo

1. When does ovulation occur? 2. How does it occur?

1. occurs on approx. day 14 (in the middle of the cycle, the end of ovulation if the beginning of the menstrual phase) 2. the pituitary gland releases luteinizing hormone (LH), which causes estrogen levels to rise, LH & FSH are released which triggers the release of the egg.

1. What is a corpus luteum cyst? 2. What is its function?

1. the crater left by the ruptured follicle; it is fatty, yellowish cells 2. The corpus luteum manufactures and secretes progesterone to prepare the uterus for a possible pregnancy. (a corpus lutuem cyst, when ruptured during ovulation, can appear as free fluid in the posterior cul de sac)

What is a fecundated ovum?

A fecundated egg is an ovum after impregnation by spermatozoa (a fertilized egg)

Know the cul-de-sacs, names, and locations.

The Pouch of Douglas, posterior cul-de-sac, or recto-uterine pouch: A sac or recess formed by a fold of the peritoneum dipping down between the rectum and the uterus Anterior cul-de-sac A similar fold of peritoneum, smaller, and located between the bladder and uterus.Also called the utero-vesical pouch or vesico-uterine pouch. (Space of Retzius is found on males between pubic bone and prostate)

Ligaments that hold the ovaries in place:

The anterior surface of the ovary is connected by the mesovarian to the broad ligament. mesovarian. The mesovarian is a short suspensory type of ligament, formed byperitoneum, which provides the primary route of access for vessels to and fromthe ovary. *The ovaries are attached to the posterior surface, therefore are confined in their movement to the posterior compartment.* The ovary's inferior extremity is connected to the uterus by the ligament of ovary or ovarian ligament -- a fibromuscular band extending from the uterine cornu.

What is mittleschmertz?

pain in the middle of the cycle when ovulation occurs

What is menarche?

The first menstrual period.

What is a zygote?

When the oocyte and the spermatozoon fuse they form the zygote. It consists of a segmentation nucleus, cytoplasm and an enveloping membrane. The fecundated ovum is now called a zygote. The zygote consists of a segmentation nucleus, cytoplasm and an enveloping membrane. (Segmentation: The process of becoming divided into similar parts. Cleavage.) (Cytoplasm: The protoplasm or substance of a cell surrounding the nucleus, carrying structures within which most of the life processes of the cell take place.) Immediately after fertilization (within a day), the zygote undergoes rapid cell division and then develops into the morula.

What is the most common reason to have an amniocentesis?

is to determine whether a baby has certain genetic disorders or a chromosomal abnormality, such as Down syndrome; can also predict fetal lung maturity, which is inversely correlated to the risk of infant respiratory distress syndrome.

How should a normal post-menopausal patient's uterus and ovaries look?

is usually atrophic and appears as sort of a smaller version of the premenopausal uterus - the corpus and fundus in particular may become reduced in size relative to the cervix. The average dimensions of the postmenopausal uterus ranges from 3.5 to 6.5 cm in length, about 2 cm wide, and is 1.2 to 1.8 cm thick. The postmenopausal endometrium usually presents a thin bright line. The endometrium is usually less than 3 - 5 mm thick, OVARIES may not be identified due to atrophic condition

Know the different types of uterine congenital malformations and anomalies. (Be able to identify them on a sonogram.)

-uterus didelphys, or uterus duplex separatus: A female with this duplication would have two vaginas, two cervices, and two uteri.-uterus duplex bicornisis, again, two uteri, but they are conjoined and share the same medial wall (also called bicornis bicollis)-uterus bicornis unicollis is the anomaly of two uteri which share the same cervix. This is the most common of the developmental anomalies encountered inthe female.Both uterus duplex bicornis (bicornis-bicollis) and uterus bicornis unicollis are usually referred to in the clinical setting and in much of the literature as "bicornuate uterus". It is also called "bicornate"-When a uterinecavity is entirely separated by a septum, the anomaly is called (uterus septus a septated uterus)-Uterine subseptus describes an anomaly in which the uterine body has a partial septum.-Uterus arcuatus exists as a minor anomaly where the endometriumis slightly indented at the fundus- Uterine unicornis is the formation of half of a uterus with only one fallopian tube attachment.- uterine aplasia or agenesis is the descriptive term for a condition that exists when the fallopian tubes come to a blind end.

1. What are transvaginal, transabdominal, and transperineal scanning? 2. What are the advantages and disadvantages of each?

1. Transvaginal (AKA: endovaginal): done inside the vagina, patient does not need a full bladder Transabdominal: scanned through the abdomen; patient must have a full bladder. Bladder is used as an acoustic window and also pushes the uterus in a more "open" position. Translabial: done through the lips of the vagina, typically done for pediatric patients who are not sexually active Transperineal: done noninvasively through the perineum

1. What hormones are involved in the menstrual cycle? 2. How are they related to each other? 3. What organ(s) is/are responsible for secreting these hormones?

1. gonadotropin hormones; FSH (responsible for ripening of the graaphian follicle), LH (induces ovulation and the lutenization changes in the ovary) and prolactin (capable of initiating and sustaining lactation with estrogen, progesterone and oxytocin present). 3. anterior pituitary gland: FSH and LH, but the hypothalamus (FSHRF, LHRF, and PIF) and the ovaries (estrogen and progesterone through the corpus luteum) are also a part of the negative feedback system 1. Luteinizing hormone (LH) (associated with luteal phase/corpus luteurn) and follicle-stimulating hormone(FSH) (stimulates formation of graafian follicle) promote ovulation and stimulate the ovaries to produce estrogen and progesterone. Estrogen develops and maintains reproductive structures and progesterone prepares uterus (and mammaries) for implantation; stimulate the uterus and breasts to prepare for possible fertilization.2. ovulation is controlled by hypothalamus, and through release of LH & FSH by pituitary gland, ovaries produce estrogen & progesterone

1. How is the gestational sac measured? 2. When is it used?

1. two methods are used to measure the gestational sac: gestational sac volume or by mean sac diameter. Most use the MSD. Gestational sac volume formula: (L x W x H / 2 or more exactly L x W x H x .523 Mean sac diameter (MSD) formula: L+W+H / 3 2. It is used before the fetal pole can be seen. The *earliest* sonographic dating of a pregnancy is done by measuring the *gestational sac*

Know when different fetal organs and structures should be visualized.

4 - 6 wks- gestational sac; 6 - 7 wks-Embryonic pole; 5-5.5 wks yolk sac, TV; 5.5 - 6.5 wks Fetal heart motion, one week sooner TV; 6-7 wks yolk sac, TA; 7 wks Fetal heart motion reliably; 7 - 8 wks first signs of the spine; 7 - 9 wks Placenta location; After 8 weeks Differentiation of the head from the trunk and recognition of the extremitybuds; 8 -12 wks some of the fetal gut can be seen external to the fetus and herniated within the umbilical cord.**Only if there is still herniation into the cord after 12 weeks (usually at 14 weeks) can an abdominal wall defect be diagnosed; 6 - 12 wks Fetal crown-rump length; 8 - 10 wks Fetal body motion first; 10 weeks echogenic choroid plexus; 10 wks Fetal spine can be well visualized, theumbilical cord can be seen inserting into the fetal abdomen; 10 wks gestation ceases to be an embryo and becomes a fetus; 10 -12 wks BPD first measureable; 10 -12 wks Femur length first measureable; 12 - 20 wks Most accurate BPD measureable; 13 - 20 wks MOST accurate femur length; 15 - 16 wks Kidneys first seen; 16 wks Bladder and stomach visualized; 18 wks Bladder MUST be seen; 12 - 27 wks Placental growth maximal

Abdominal Circumference

Abdominal Circumference- is taken at the level of the umbilical vein where it branches into the left portal sinus. AC = D1 +D 2 divided by 2, times pi (3.14) or AC = D1 + D2 times 1.57

Know the location of the fetal organs and what portion of the abdomen they fill.

Abdominal Circumference- is taken at the level of the umbilical vein where it branches into the left portal sinus. AC = D1 +D 2 divided by 2, times pi (3.14) or AC = D1 + D2 times 1.57 *The normal kidneys should be about 30% to 1/3 of the abdominal diameter.*

Know the terms anteflexed, anteverted, retroflexed, and retroverted. (Be able to identify them on a sonogram or diagram.)

Anteflexoion: signifies the forward displacement of the body on the cervix Retroflexion: backward displacement of the body on the cervix at the level of the internal os Normal uterine position: anterverted Most common displacement: retroverted

What is an amniocentesis?

Aspiration of the amniotic fluid. A medical procedure used in prenatal diagnosis of chromosomal abnormalities and fetal infections, and also used for sex determination in which a small amount of amniotic fluid, which contains fetal tissues, is sampled from the amniotic sac surrounding a developing fetus, and the fetal DNA is examined for genetic abnormalities.

BPD (biparietal diameter)

BPD: The BPD should be taken in the transaxial (transverse) plane with the margins of the calvaria symmetrical and which demonstrates the thalami and third ventricle in a true central position between the parietal bones or skull walls. (Leading edge to leading edge)

What is the relationship of BPD's in twin pregnancies?

Differences between BPD's of 5 mm or greater or of HC's of greater than 5% isconsidered significant, especially if seen before 30 weeks. Head discordancyafter 30 weeks may carry a better prognosis than if it is found before 30 weeks,since some individual variations can be found in size and weight (although itshould still raise enough suspicion to measure other parameters).

Know what IUD's are and their purpose.

LIPPES LOOP: was at one time the most common type of IUD used in routine practice and is the easiest to recognize with ultrasound scanning. This is very often a double parallel line of interrupted echoes. This pattern is due to "entrance-exit" reflections. the DALKON SHIELD was discontinued in the 1970's, there are a few women still using it and it is still rarely encountered in practice. (Less and less frequently now - there have been numerous lawsuits filed and won because of the very serious complications resulting from its use). It is the smallest of the once more commonly used IUD's and is shaped something like a bug with numerous legs or hooks. The SAF-T-COIL (seldom seen anymore in this country) consists of a double coil with a central arm. For this reason, it can manifest in several ways on ultrasound studies

What are the maternal and fetal parts of the placenta?

Maternal = decidua basalis (formed by portion of the endometrium of the mother)- decidua parietalis: (or decidua vera) The portion of the modified endometrium that lines the entire pregnant uterusexcept where the placenta (chorionic vesicle) is forming.- decidua capsularis: The portion that overlies the conceptus (or chorionic vesicle), and which faces the uterine cavity.- decidua basalis --> becomes maternal part of the placentaFetal = chorion becomes fetal contribution to the placenta- trophoblast: the outer layer of flattened cells forming wall of blastocyst- cytotrophoblast: inner --> forms chorion- syncytotrophoblast: outer layer of placenta

What is monozygotic, dizygotic, dichorionic, monochorionic and other terms that refer to these types of twin gestations?

Monochorionic- twins sharing a single placenta; Dichorionic- each twin has a separate placenta; Dizygotic (Fraternal twins)(Binovular twins)- two (or more) ova shed by the mother in a single ovulatory cycle, which are separately fertilized and implanted. Monozygotic (Identical twins)(Uniovular twins)- a single conceptus into two (or more) individuals. Monoamniotic- twins sharing an amnion; Diamniotic- each twin has a separate amnion

1. What is a morula and blastocyst? 2. What is their relationship?

Morula: A solid ball of cells that makes up an embryo; in humans, this stage occurs within four days of fertilization. (occurs before the blastocyst stage and implantation) Blastocyst: a hollow ball of cells; the inner cell mass is destined to develop into the embryo, cord, amnion, and secondary yolk sac. The outer cell mass will become the trophoblasts.

Know the structures of the brain and be able to identify them on a sonogram.

Occipital horn can be seen below the level of the thalamus inline with the peduncles and falx Interhemispheric fissure deep groove or indentation separating the right and left cerebral hemispheres, contains the fall cerebri choroid plexus highly vascular portion of the lining of the ventricles in the brain that secretes cerebrospinal fluid (CSF) which cushions brain and spinal cord. Lateral ventricles contain the choroid plexus Cerebellar vermis Structure located between two lobes of cerebellum; median part of the cerebellum What are the landmarks used for measuring the BPD? level of the thalamus, third ventricle and cavum septum pellicidum What are the normal cisterna magna measurements? from 3 - 11 mm, with an average size of 5 - 6 mm; obtained by measuring from the vermis to the inner skull table of the occipital bone

1. What is PID? 2. What causes it and what is the treatment?

PID is the most common pelvic pathology seen in women of ages 15 - 25. The vast majority of cases of PID are caused by more than one organism. Up until recently (and still in many textbooks), the gonococcus organism and chlamydia - two sexually transmitted diseases (STD's) - were said to cause most PID. They probably do initiate the process by being the first organism to penetrate the cervical barrier. Then other organisms travel into the genital tract and cause the infection process to continue. But something has to start the process, and the fact is that the majority of patients with PID have or have had gonorrhea or chlamydia, and this is the initial cause of the infection.PID due to gonorrhea or chlamydia spreads along the mucous membranes and travels from the external genitalia or cervix to the adnexa and/or the peritoneum. The vast majority of PID cases are ascending infections Elevated WBC count' With early PID, the endometrium may appear prominent and hyperechoic and may be surrounded by a hypoechoic ring. The uterine cavity may contain a fluid collection as a result of the inflammatory process (pyometrium). The uterus texture may show a loss of echogenicity (look more hypoechoic) due to edema Pyogenic PID can result in a gas containing abscess in the endometrial cavity which may present with an acoustic shadow behind the gas. The edematous pelvic structures may exhibit fuzzy or indistinct borders. There is often fluid in the cul-de-sac which may have echoes in it if it contains blood or pus. Endometriosis and PID are easily confused. PID can be cured with several types of antibiotics. A health care provider will determine and prescribe the best therapy. However, antibiotic treatment does not reverse any damage that has already occurred to the reproductive organs. If a woman has pelvic pain and other symptoms of PID, it is critical that she seek care immediately

Obturator Internus Ultrasound

Sonographically, the muscle mass is considered to be a low-level reflector seen laterally on transverse scans.

What are the adnexal structures?

Structures outside of the uterus: ovaries, fallopian tubes, muscles, ligaments

What structures make up the placenta?

The *fetal placenta (Chorion frondosum),* which develops from the same blastocyst that forms the fetus, and the *maternal placenta (Decidua basalis)*, which develops from the maternal uterine tissue fuse together to form the placenta

1. How is the placenta measured? 2. What are the normal limits?

The average thickness is **3 cm but it is markedly thinner toward the edges. It can be up to 5 cm thick, although some authors say over 4 cm is abnormal. (I consider 4 cm ok unless other reasons to suspect pathology are present) **Anything greater than 5 cm thick should be considered abnormal. Also, after around 23 - 24 weeks, if it is less than 1.5 cm thick at its center, it is considered abnormal.

Ligaments that hold the uterus in place:

The broad and cardinal ligaments provide the uterus with lateral and superior stability (mostly the cardinal ligament; the broad ligament may help a little, but to a much lesser extent.) The *paired broad or lateral ligaments: are winglike double folds of parietal peritoneum which extend from the sides of the uterus to the lateral walls of the pelvis.* These lateral ligaments form a septum across the pelvis which in completely divides the true pelvis into anterior and posterior compartments. The two *sacro-uterine or utero-sacral ligaments* are the condensation of the cardinal ligaments. These are located on either side of the rectum. They attach the lateral margins of the uterus at the level of the isthmus to the second and third sacral bones. The pair of *round ligaments* extend anterior to the fallopian tubes in the broad ligament anterolaterally, and insert into the fascia of the external genitalia (labia majora). The round ligaments maintain the corpus and fundus of the uterus in its normal anteverted, slightly anteflexed position The *cardinal ligaments aka lateral cervical ligaments,* are extensions below the base of the broad ligament between the pelvic wall, the cervix and the vagina. They serve as the *CHIEF ligaments* supporting the uterus. They keep it superiorly attached and prevent it from dropping into the vagina, and help maintain it's side-to-side position.

1. What is the double decidual sac sign? (Be able to identify it on a sonogram or diagram)

The chorionic villi (trophoblasts) and the decidual reaction appear as the echogenic partially double ring

What are the DFE and the PTE?

The distal femoral epiphyseal ossification (DFE) and the proximal tibial epiphyseal ossification (PTE) have been correlated with advanced gestational age. The DFE and PTE appear as a high amplitude echo that is separate but adjacent to the femur or tibia.It is thought that the DFE can be identified in gestations greater than 33 weeks and the PTE is identified in gestations greater than 35 weeks.

Know how the fetal heart is situated in the thorax.

The fetal heart fills approximately 1/3 of the thorax and lies at an angle of about45 degrees from a line drawn from the spine to the anterior midline of the body. The left atrium is the most posteriorly situated chamber; the right ventricle is the most anterior.

How does a fetus receive its oxygen and nutrient?

The fetus receives its nutrition from the mother through the placenta and the umbilical cord. The umbilical cord serves as the lifeline for the fetus. The two arteries carry deoxygenated blood pumped from the left ventricle of the fetal heart to the placenta, The vein returns the OXYGENATED blood from the placenta back to the right atrium of the fetal heart.

1. What are gonadotropin hormones? 2. What is their function?

The gonadotropic principles of gonadotropin hormones are *FSH (responsible for ripening of the graaphian follicle), LH (induces ovulation and the lutenization changes in the ovary) and prolactin (capable of initiating and sustaining lactation with estrogen, progesterone and oxytocin present).*

1. What are trophoblasts? 2. What terms are used to describe them>

The layer of tissue that forms the wall of the blastocyst; It functions in the implantation of the blastocyst in the uterine wall and in supplying nutrients to the embryo. the cells then differentiate into two layers, *the inner cytotrophoblast, which forms the chorion, and the syncytiotrophoblast, which develops into the outer layer of the placenta.* An important role of the trophoblasts is to secrete HCG (human chorionic gonadotropin hormone), which maintains the corpus luteum and is the basis of pregnancy tests.

Know the location of the uterus, bladder, vagina, ovaries, ureter, fallopian tubes, and illiac vessels and their relation to each other in the pevlis.

Uterus location and size The upper end or base is projected upward (superior) and forward (anterior). The lower end or apex projects downward (inferior) and backward (posterior). 7 - 8 cm. in length,4 - 6 cm. in width, 2 - 4 cm. in the (AP) Ovaries location and size they are located in the posterior of the broad ligament, posterior and distal to the fallopian tube; 3 cm in length, 2 cm in width, and 1 cm in AP Ureter location can be distinguished from the internal iliacvessels by their more medial location and the lack of branching caudal to the ovary and by their more echogenic wall. They enter the bladder lateral and anterior to the cervix on each side of the urethra. Fallopian tube location on either side at the junction of the fundus with the body or corpus of the uterus. This area is called the cornua. cornu = horn or horn shaped cornua = pleural of cornu Iliac vessel location: EXTERNAL iliacs remain intimately related to the *medial aspect of the iliopsoas muscle.* They can be visualized in transverse and oblique longitudinal planes at the medial margin of the iliopsoas muscle. *INTERNAL iliacs* pass into the true pelvis and are not often seen on transverse TA scans. On longitudinal scans angled toward the pelvic sidewall, the *internal iliac veins and arteries can be imaged posterior and lateral to the ovary.* *The internal iliac (AKA: HYPOGASTRIC) artery is the principle source of pelvic vasculature.* *It follows a more posterior course than the external iliac and enters the true pelvis at about the level of the sacral prominence.*

(Fallopian tube anatomy/function)

function: - transport the fecundated ovum to the uterus by means of peristaltic contractions and the action of the cilia of the mucosal lining cornua --> interstitial --> isthmus --> ampulla --> infindibulum --> (fimbriae)3 coats: 1. The external or serous coat (serosa) is peritoneum 2. The middle layer is a muscular 3. The internal or mucous coat is continuous with the mucous lining of the uterus at the interstitial portion.

Which muscles can be identified on a sonogram? (Be able to describe them and identify them on a sonogram.)

illiopsoas --> Sonographically, it is identified superolaterally (anterolaterally too) and is considered a low-level reflector with a high-level central reflective area.

What are the fetal and maternal complications with a twin pregnancy?

intrauterine growth retardation (restriction), fetal distress and premature labor; and delivery with all the complications for the fetus that accompany prematurity (e.g. lung maturity, chronic lung disease, intracranial hemorrhage, bowel infarctions as in necrotizing enterocolitis,etc.). Premature birth is the most frequent complication. In addition, there is an increased incidence of the following complications with multiple gestations:Increased maternal and fetal morbidity and mortality to include:abnormal presentations anemia preeclampsia and eclampsia antepartum and postpartum hemorrhage (ante = before, in time or in place) abruptio placenta prolapsed umbilical cord premature rupture of membranes cesarean section placenta previa congenital malformations (higher incidence with monozygotic than dizygotic and includes neural tube defects, heart defects, hydrocephalus, hip dislocations, club foot,others)uterine dysfunction intrauterine infection Other problems, including maternal hepatic cholestasis orpyelonephritisThe risks of prematurity, growth restriction, and accelerated onset of post mature placental insufficiency affect all multiple gestations. It is clear, however, that the more fetuses, the higher the risk, and that monochorionic twins suffer disproportionately more than dichorionic twins from these problems. The perinatal mortality rate for monozygotic twins is approximately three times that fordi zygotic twins. Monochorionic twins are also at specific additional risk from twin transfusion syndrome, twin embolization syndrome, conjoined twins, and acardiac parabiotic twin syndrome. Monochorionic monoamniotic twins are most at risk. These have about a 50%mortality rate.

What are the layers that comprise each of the following: the ovary, uterus, and fallopian tubes.

layers of the ovaries: outer layer-germinal epithelium of Waldeyer; just beneath is tunica albuginea; substance of ovary is cortex; inner area is medulla or stroma layers of the uterus: outer layer-serous coat, the serosa; myometrium is the muscular middle layer; internal layer-endometrium layers of the fallopian tubes: external or serous coat; middle layer is a muscular coat; internal or mucous coat is continuous with the mucous lining of theuterus at the interstitial portion.

How does the infantile uterus differ from the adult uterus?

long axis is parallel to the long axis of the body. It is situated in the pelvic cavity between the bladder and the rectum. The cervix makes up about one-half, or even up to two-thirds, of the uterus; As the female matures, the uterus becomes pear-shaped and more flattened. The corpus (or body) becomes larger than the cervix. This increased growth of the corpus to where it becomes approximately two-thirds of the uterus occurs sometime around menarche.

1. What is crown-rump length? 2. When is it used?

measurement of fetus from top of the head to bottom of bum excluding the yolk sac How is the CRL taken? from the top of the fetal head to the outer rump, excluding the limbs or yolk sac When is the CRL measurement used? 6-12 weeks; less reliable after that The CRL is the most accurate measurement of all but is not available after 13-14 weeks and is less accurate after 12 weeks due to the curvature of the fetus.

Know the phases of the endometrium and be able to identify them on a sonogram.

menstrual phase (early proliferative) has a thin and broken/patchy-looking endometrium; proliferative phase has 5 layers; secretory phase has the thickest and most echogenic endometrium 1. menstrual phase endometrium: Thin stripe (mucosal lining); can be broken or patchy; may see anechoic center rep blood between layers of mucosa (early proliferative in the image) 2. proliferative phase endometrium: early: thin echogenic stripe (not as bright as secretory phase) late(periov): endo appears multilayered 3. secretory phase endometrium: thickest and most echogenic

What is the zona pellucida?

middle layer which covers the ovum. It is a transparent noncellular membrane that encloses the ovum. It is secreted by the ovum during development in the ovary, is penetrated by the fertilizing sperm cell, and is retained until near the time of implantation.

Know the fetal circulation from the mother to the fetus. 2. Know what each vessel(s) is/are responsible for.

oxygenated, nutrient-rich blood from placenta carried to fetus via umbilical vein → half enters Ductus venosus (allows blood to bypass the liver) →carried to inferior vena cava → RA → RV → Ductus arteriosus (conducts some blood from the pulmonary artery to the aorta [bypassing the lungs/fetal pulmonary circulation]) → aorta. Other half enters liver/portal vein → RA → Foramen ovale (allows blood to bypass pulmonary circulation by entering the left atria directly from the right atria since there is no gas exchange in fetal lung) → LA → LV → aorta.

What is a cerclage?

suturing the cervix closed with a nonabsorbable suture material.

What is macerated?

the degenerative changes and eventual disintegration of a fetus retained in the uterus after its death.