Chapter 57 power point Amniotic Fluid

Question 1

Allows fetus to move freely within amniotic cavity

Maintains intrauterine temperature

Protects developing fetus from injury

Answer 1

Role of Amniotic Fluid

Question 2

Interfere with normal fetal development 
Cause structural abnormalities 
Be an indirect sign of an underlying anomaly 
Neural tube defect 
Gastrointestinal disorder

Answer 2

Abnormalities of the fluid

Question 3

Amniotic cavity forms early in fetal life and is filled with amniotic fluid (AF)
Fluid completely surrounds and protects embryo and fetus
AF is produced by umbilical cord, membranes, lungs, skin, and kidneys
Amount of AF reflects balance between AF production and removal

Answer 3

Amniotic Fluid production

Question 4

As fetus and placenta mature, AF production and consumption change

includes:
Movement of fluid across chorion frondosum and fetal skin
Fetal urine output and fetal swallowing
Gastrointestinal (GI) absorption

Answer 4

Changes in Amniotic Fluid

Question 5

Portion of chorion that develops into fetal portion of placenta
Site where water exchanged freely between fetal blood and AF across amnion

Answer 5

Chorion frondosum

Question 6

Fetal production of urine and ability to swallow begins between 8 and 11 weeks of gestation

Amount of urine produced is most significant at approximately 18 to 20 weeks’ gestation
Fetal urination into sac accounts for nearly total volume of AF by second half of pregnancy

Quantity of fluid directly related to kidney function

Fetus with malformed kidneys or renal agenesis results in little or no AF

Answer 6

Fetal Amniotic Fluid exchange

Question 7

Amount of AF regulated by:
Production of fluid 
Removal of fluid by swallowing
Fluid exchange within lungs
Membranes and cord

Answer 7

Quantity of Fluid

Question 8

Normal lung development depends on exchange of AF within lungs

Inadequate lung development may occur when amount of AF severely low
This places the fetus at high risk for developing small, or hypoplastic, lungs

Answer 8

Amniotic fluid influence on lung developement

Question 9

By 20 weeks’ gestation, AF volume increases by 10 ml/day

Fluid produced by fetal urination slightly exceeds amount removed by fetal swallowing

Answer 9

Highest level of Amniotic fluid

Question 10

Uterine cavity divided into four equal quadrants by two imaginary lines running perpendicular to each other

Largest vertical pocket of AF, excluding fetal limbs or umbilical cord loops, is measured

Answer 10

Amniotic Fluid Index (AFI)

Question 11

AFI of 10 to 20 cm

Answer 11

Normal AF

Question 12

AFI Values of 5 to 10 cm

Answer 12

indicate low fluid

Question 13

AFI values of 20 to 24 cm

Answer 13

indicate high fluid

Question 14

(fluid should measure >1 cm “rule”) assessment of AF done by identifying largest pocket of AF

Pocket of fluid should be clear of fetal components and umbilical cord

Answer 14

Maximum vertical pocket

Question 15

Defined as AF volume of >2000 ml

Associated with increased perinatal mortality and morbidity and maternal complications

Patient will present with clinical finding of uterus greater than dates

Sonography ordered to rule out multiple gestation, molar pregnancy, or fetal size greater than dates

Answer 15

Polyhydramnios

Question 16

associated with central nervous system (CNS) disorders and/or gastrointestinal (GI) problems

CNS disorders cause depressed swallowing.

GI abnormalities result in ineffective swallowing that are often caused by a blockage (atresia) of the esophagus, stomach, duodenum, or small bowel.

Answer 16

Polyhydramnios complications

Question 17

Diabetes mellitus
Obesity
Rh incompatibility
Anemia
Congestive cardiac failure

Answer 17

Maternal conditions associated with polyhydramnios

Question 18

Overall reduction in amount of AF resulting in fetal crowding and decreased fetal movement

Estimated incidence between 0.5% and 5.5% of all pregnancies

Estimates depend on:
Population tested
Criteria used for diagnosis

Answer 18

Oligoyhydramnios

Question 19

Congenital anomalies 
IUGR
Postterm pregnancies
Rupture of membranes (ROM)
Iatrogenesis

Answer 19

1st trimester oligohydramnios

Question 20

often has poor prognosis, especially if maternal serum alpha-fetoprotein level also elevated

Answer 20

Second trimester oligohydramnios

Question 21

Hypertension 
Preeclampsia 
Chronic cardiac or renal disease
Connective tissue disorders 
Patients receiving indomethacin

Answer 21

Maternal conditions associated with oligiohydramnios

Question 22

Fetal hypoxemia may produce growth restriction and oligohydramnios.

Four-fold increased risk of growth delay when oligohydramnios present

Doppler evaluation of growth-restricted fetus shows abnormal umbilical flow in patients with oligohydramnios

Answer 22

Clinical Findings oligohydramnios

Question 23

_____________ insufficiency may cause IUGR associated with ___________

Answer 23

placental

oligohydramnios

Question 24

Medications
Insensible fluid loss
Maternal intravascular fluid depletion
Prior procedures such as CVS

Answer 24

Iatrogenic causes of oligohydramnios

Question 25

Nonsteroidal antiinflammatory drugs Angiotensin-converting enzyme inhibitors Calcium channel blockers Nitrous oxide

Answer 25

Medications associated with oligohydramnios

Question 26

IUGR Premature rupture of membranes Postdate pregnancy (42 weeks) Chorionic villus sampling

Answer 26

Causes of Oligohydramnios | Nonanomalous Conditions

Question 27

``` Infantile polycystic kidney disease Renal agenesis Posterior urethral valve syndrome Dysplastic kidneys Chromosomal abnormalities ```

Answer 27

Causes of Oligohydramnios | Fetal Anomalous Conditions

Question 28

Tissue makeup of chorioamniotic membrane composed of several types of cells Integrity and makeup of cells aid in determination of strength of membrane Under normal conditions, chorioamniotic membranes rupture due to normal cell death activation of enzymes and mechanical forces

Answer 28

Ruptured Fetal Membranes

Question 29

Premature rupture of membranes

Answer 29

PROM

Question 30

spontaneous rupture of membranes

Answer 30

SPROM

Question 31

Patients suspected to have ROM present clinically with sudden gush or leaking of fluid. test used as screening test to determine presence of AF in vaginal secretions Patient is checked for cervical dilatation and for leaking of fluid with coughing or fundal pressure

Answer 31

Nitrazine test

Question 32

``` Preterm delivery Fetal and neonatal death Neonatal respiratory distress Prolapsed umbilical cord Chorioamnionitis Placental abruption ```

Answer 32

Abnormal ROM associated

Question 33

depends on fetal GA, fetal status, and ability to control uterine contractions

Answer 33

Prognosis with ROM

Question 34

Is associated with abnormality in fetal membranes Is a common, non-recurrent cause of various fetal malformations involving limbs, craniofacial region, trunk

Answer 34

Amniotic Band Syndrome

Question 35

amniotic deformities, adhesion, mutilation

Answer 35

ADAM complex

Question 36

ADAM complex Amniotic band sequence Aberrant tissue bands Congenital constricting bands

Answer 36

Synonyms used to describe disruption of fetal tissue due to the presence of amniotic bands

Question 37

Most widely accepted is rupture of amnion during early pregnancy development leads to subsequent entanglement of various embryonic or fetal parts by fibrous mesodermic bands, which emanate from chorionic side of amnion Entrapment of fetal parts by bands may cause lymphedema, amputations, slash defects in nonembryologic distributions

Answer 37

Amniotic Band Theory

Question 38

Facial clefts, asymmetric encephaloceles, constriction or amputation defects of extremities, clubfoot deformities

Answer 38

Amniotic band Common findings

Question 39

identified as echogenic, nonfloating bands crossing through amniotic cavity Are thicker than bands associated with amniotic band syndrome Do not cause fetal malformations Most likely signify uterine synechiae

Answer 39

Amniotic Sheets, shelves or folds

Question 40

Uterine scars from previous instrumentation used in uterus Cesarean section Episodes of endometritis

Answer 40

amniotic sheets caused by:

Question 41

Patients with history of endometrial D&C, intrauterine infections, endometritis, removal of fibroids or endometrial polyps, or prior cesarean section are at risk for developing uterine scars. Synechiae associated with infertility and miscarriages Patients who present with uterine synechiae and infertility often diagnosed with

Answer 41

Asherman’s syndrome

Question 42

Disparity between amounts of serous fluid being produced and absorbed

Answer 42

Hydrops

Question 43

``` Pleural effusions Ascites Cardiac effusion Skin edema Anasarca ```

Answer 43

Hydrops indications

Question 44

``` Enlarged umbilical cord Polyhydramnios Placental edema Enlarged liver and spleen In many cases, highly associated with mortality ```

Answer 44

Hydrops fetal findings

Question 45

Hydrops is identified on ultrasound by presence of abnormal collections of fluid Ascites can be seen as anechoic fluid surrounding abdomina, pelvic organs, and umbilical cord Do not to mistake normal hypoechoic abdominal musculature for ascites (pseudoascites).

Answer 45

Hydrops sonographically

Question 46

can be seen as increased skin thickening around the skull, neck, extremities, or abdomen. Measurement of >5 - 6 mm for soft tissue thickness is used for diagnosis in some reports

Answer 46

Hydrops skin edema

Question 47

When skin edema is massive, encasing the majority of the body,

Answer 47

anasarca

Question 48

can be identified as a thickened placenta measuring >4 - 4.5 cm in true anterior-posterior diameter

Answer 48

placental edema w/hydrops

Question 49

Is associated with alloimmune hemolytic disease (erythroblastosis fetalis) or rhesus (Rh) isoimmunization Maternal blood sampling and history of previously affected fetus extremely important for pregnancy management

Answer 49

Immune Hydrops

Question 50

Nonimmune hydrops fetalis (NIHF): Presence of abnormal accumulations of fluid in fetal body and/or skin Is associated with numerous conditions and causes

Answer 50

Nonimmune Hydrops

Question 51

May be sporadic condition or associated with numerous other causes Cardiac insufficiency one of the most common causes Cardiac insufficiency can result from cardiac anomalies (tumors) or arrhythmias (tachycardia)

Answer 51

Nonimmune Hydrops causes

Question 52

All abnormal fluid collections should be documented and measured. Fetus should be thoroughly evaluated for anomalies that may be associated with NIHF.

Answer 52

Nonimmune Hydrops sonographically

Question 53

Fetal tumors (heart or liver) Cardiac anomalies Cystic adenomatoid malformation of lung Chorioangioma of placenta

Answer 53

Nonimmune Hydrops anomalies

Question 54

Trisomy 21 45X Fetal infections (TORCH)

Answer 54

NIHF, sonographic findings associations documentation