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45 Cards in this Set
- Front
- Back
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Measurements for Dating
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Sac volume 5 weeks
CRL 6.5 weeks BPD 12 weeks Femur Length 12 weeks Cerebellar width 15-16 weeks |
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US Features of a Normal Intrauterine Pregnancy
5 weeks |
Gestional sac visible at the fundus
The gestational sac is surrounded by an echodense ring Assymetry of this ring is apparent |
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US Features of a Normal Intrauterine Pregnancy
6 weeks |
embryonic structures apparent
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US Features of a Normal Intrauterine Pregnancy
6.5 weeks |
cardiac movement identifiable within the fetus CRL approx. 5mm
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Indications for US Scanning inthe First Trimester
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Threatened miscarriage
Pelvic pain Suspected Ectopic Uncertain LMP Evaluation of retained products |
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Threatened Miscarriage
Definition: Blood per vagina with a closed cervical os |
Incidence 25% of all pregnancies-50% go on to abort
Demonstration of a living fetus 90-97% favorable outcome. |
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Anembryonic Pregnancy (Blighted Ovum)
Definition: A fertized ovum in which development has been arrested. The majority have chromosomal abnormalities. |
No fetal parts seen within a sac diameter > 30mm
No yolk sac seen within the gestational sac > 20mm Irregular sac contour Abnormal implantation site |
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Ectopic Pregnancy
Risk factors |
previous ectopic
IUCD in situ Hx of PID Previous tubal surgery Assisted conception IVF |
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Ectopic Pregnancy
US Findings |
US evidence of intrauterine pregnancy excludes ectopic (1/30000 heterotopic pregnancy
Endometrial thichening (pseudogestational sac) Adnexal mass Demonstration of a living fetus outside of the Uterus 1/7000 IVF) |
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Absent Intrauterine Pregnancy with a Positive Pregnancy Test
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Ectopic
Early intrauterine pregnancy , 5 weeks recent complete/incomplete abortion |
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Routine Anomaly Screening
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measure bpd, head cicumference and femur length
head shape and internal structures cavum septum pellucidum, cerebellum, ventricular size at the atrium < 10mm Spine Longitudinal and transverse Abdominal shape and contents at the level of the stomach Abdominal shape and contents at the level of the kidneys and umbilicus Renal pelvis , 5mm Longitudinal Axis thoracic abdominal appearance (diaphragm/bladder) Thorax at the level of the 4 chamber view Arms 3 bones Legs 3 bones Cardiac outflows face and lips |
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Liquor volume
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Increases until approximately 34 weeks then decreases to term
(at 20 weeks it maesures 400ml) AFI 4 lateral quadrants |
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Liquor volume
DD of Abnormal Liquor volume |
Severe oligohydranious
i)renal agenesis/bilaterally non-functioning kidneys ii)premature rupture of membranes iii)severe growth restriction Moderate Oligohydramnious i) real anomalies ii) premature rupture of membranes iii) Growth restriction Polyhydramnious Diabetes Maternal Fetal anomalies (fetus hydropic, cardiovascular anomalies, obstructive malformation of the GIT (eg tracheoesophageal fistula, duodenal stenosis) space occupying lesion in the thorax resulting in disordered swallowing, rarer cusess bone dysplasias, neuromuscular disorders) |
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Fetal Hydrops
Definition: skine edema and at least one of the following, ascites, pleural or pericardial effusion |
IMMUNE HYDROPS
Rhesus incompatibility Other blood groop incompatibility NON IMMUNE HYDROPS Cardiovascular (arythmias, anatomical defects, cardiomyopathies) Chromosomal (Turner's Treisomies, Triploidy) Infections (CMV, Toxo, Rubella, Syphilis) Twin Pregnancies (twin to twin transfusion) Hematological (alpha thalasemia, large AV shunt) Thoracic mass lesions (hiatis hernia, CCAM, Pulmonary lymphangectasia) Gastronitestinal (atresia, volvulus, perforation) Umbilicus/Pacenta (choriangioma, fetomaternal transfusion) Urinary (congenital nephrosis) Misc (skeletal dysplasia, fetal tumors) |
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Raised Serum Alpha-Fetoprotein
Protein produced by the fetus and crosses the placenta to enter the maternal blood. The level rises during normal pregnancy. For abnormality screening best tested 16-18 weeks. |
Wrong dates
Twins Missed Abortion CNS abnormalities (anen cephaly, spina bifida, encephalocele) Renal anomalies (renal agenesis, multicystic dysplasia, hydronephrosis) Anterior Wall Defects (omphalocele, gastroschisis) |
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Ultarsound Signs suggesting a Chromasomal Abnormality at 11-13 weeks
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nuchal translucency related to gestation and maternal age)
Cystic hygroma Hydrops |
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Ultarsound Signs suggesting a Chromasomal Abnormality at the 20 week Anomaly scan
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Cystic Hygroma
Hydrops Hydrocephalus Omphalocele Gross Renal Anomalies Major Structural Cardiac Defects (cushion defects) Symmetrical growth restriction Severe growth reytardation Duodenal stenosis/atresia Single umbilical vein (associated with any structural anomaly) Abnormal placenta (cystic and thickened) Nuchal Membrane > 6mm in 2nd Trimester |
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Soft Markers of Chromosomal Disorders
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Choroid plexus cyst
Mild ventriculomegaly Echogenic Focus in the cardiac ventricles Pyelectasis Echogenic bowel |
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Cystic Structure Seen in the Fetal Abdomen
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Renal (multicystic dysplasia, hydronephrosis, bladder in outflow obstruction)
Gut obstruction ( duodenal (double bubble) jejunal (multiple filled loops - both with polyhydramnious) Ovarian cyst (simple, complex associated with torsion) Mesewnteric Cyst Reduplication Cyst Hepatic cysts Pancreatic cysts Lymphangioma |
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Major Structural Abnormalities Diagnosable Antenatally
Renal |
Hydronephrosi
Multicystic dysplastic Kidney Autosomal Reccesive polycystic disease Autosomal Dominant dominant polcystic disease |
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Abnormalities Diagnosable Antenatally
CNS |
Anencephaly
Spina Bifida |
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Abnormalities Diagnosable Antenatally
Anterior Abdominal Wall Defects |
Gastroschisis (a defect seperate to the cord insertion through which small and large bowel herniates. No covering membrane. Umbilical vessels not involved. Long term prognosis good. not associated with other defects)
Omphalocele (abodominal wall defect resulting from failure of small bowel to re-enter abdomen. Membrane (amnion) covers the eventrated viscera (small bowel +/- liver) Umbilical veis pass through the defect. High incidence .30% of chromosomal abnormalities. Poor Prognosis) |
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Abnormalities Diagnosable Antenatally
Congenital Diaphragmatic Hernia |
Incidence 1/2000 - 1/5000
High association with other anomalies Motality 80% US displaced heart with bowel within the thorax polyhydramnious may occur late in pregnancy |
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Abnormalities Diagnosable Antenatally
Cardiac Anomalies |
Normal exan requires the visualization of
4 chmbers with an intact ventricular septum Normal AV valvles Normal Srmilunar Valves Normal Connections of the Great Vessels Complete heart block is associted withmaternal SLE and positive Rho and anti cardiolipin antibodies |
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Abnormalities Diagnosable Antenatally
Skeletal Anomalies |
Lethal
Achodrogenesis Thanatophoric Dwarfism Somrtimes Lethal Chondroectodermal dysplasia Chondroplasia punctata Not Usually lethal Achondroplasia Lethal with a narrow thorax Thanatropic dysplasia achondroplasia asphyxiating thoracic dysplasia |
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Fetal Growth
Fetal measuremeents of growth |
abdominal circumferencew
head circumference |
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Types of Growth Restriction
Type 1 |
Time of onset 2nd trimester. Form is symmetrical with the whole of the body being affected.
Causes: genetic (low growth potential) chromosomal Malformations intauterine infections severe placental insufficiency drugd (alcohol, smoking) |
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Types of Growth Restriction
Type 2 |
Time of onset 3rd trimester.
Form is assymetric, the trunk is more affected that the head. Causes: hypertension maternal renal or vascular disease placental insufficiency idiopathic |
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Abnormalities of the Placenta Praevia
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Definition part of the placenta covers the cervical os.
20% at 20 weeks (low lying) 0.5% at term Incidence increases with: maternal age multiparity previous uterine surgery |
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Abnormalities of the Placenta Praevia
Classification |
symmetrical complete
assymetrical complete marginal praevia low lying placenta |
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preterm delivery
increased perinatal mortality Associations |
maternal hemorrhage
preterm delivery increased perinatal mortality intaruterine growth (last three related to detachment of the placenta)retardation |
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Placental Hemorrhage
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Retroplacental
Marginal Preplacental Intervillous thrombis (DD maternal venous lakes) |
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Placental Abruption
Definition: premature separation of normally sited placenta Maternal Risk factors |
hypertension
vascular disease smoking Drug abuse cocaine fibrois trauma |
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Gestational Trophoblastic Disease
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Definition: Proliferative disease of the trophoblast
Classification hydatidiform mole invasive mole choriocarcinoma Risk factors Inceasing maternal age previous mole Incidence Geographic Variation 1/2000 USA 1/100 Indonesia US Appearance. large echogenic mass occupying the uterine cavity qith multiple fluid levels Raised B-HCG in 100% of cases Association Theca Lutein Cysts (multiseptate in 20-50% of patients |
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Normal Uterus
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Nulliparous postpubertal 7X4X5
Multiparity increases the uterine size 1 cm in all directions Postmenopausal Size of the Uterus progressively reduces folowing the menopause |
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Endometrial Thickness
Normal |
prolipherative phase 3-5mm
Secretory phase 5-6mm Postmenopausal <4mm |
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Endometrial Thickness
Increased |
Early intrauterine pregnancy
ectopic pregnancy estrogen excess Endometrial hyperpalsia/carcinoma (> 4mm abnormal for post menopausal women) Endometrial Polyp |
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Enlarged Uterus
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Pregnancy
Leyomyoma Carcinoma endometrial sarcoma (rare) Congenital uterine anomaly (uterus didelphys) |
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The Normmal Ovary
lenght X width X depth X 0.5223 |
Child 1 ml
Normal post pubertal state 5.3-7.6 my (excludes a dominant follicle Normal post menopausal state 4.3 ml (range 1.5-10.3) |
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Ultarsound Signs of Ovulation
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Collapse of Follicle
Free fluid in the pouch of Douglas Echo free zone aroud the endometrium-myometrial edema |
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Definition of simple cystic structures in the Ovary
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Developing Follicle 0.4-1.4 cm
Mature Follicle 1.5-2.9 cm Follicular Cyst > 3cm |
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Ovarian Mass
Simple cystic structures |
follicular cyst (may be functioning ie hormone secreting
Cystadenoma polycystic ovaries |
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Ovarian Mass
Complex (mainly cystic) |
cystadenocarcinoma
dermoid abcess endometriosis ectopic pregnancy |
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Ovarian Mass
Complex (mainly solid) |
cystadenocarcinoma
dermoid granulosa cell tumor ectopic pregnancy |
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Ovarian Mass
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Mets
Adenocarcinoma Solid teratoma fibroma lymphoma arrhenoblastoma (arrhenoblastoma is a rare ovarian stromal neoplasm that secretes testosterone) |
