Fetal complications Flashcards
Defined as a fetus weighing below the 10th percentile for gestational age
Intrauterine growth retardation IUGR/ Fetal growth restrictions
The most accurate dating of a pregnancy is by the first trimester ________ _________ _______or a firmly known _______ _______ __________ ___________
Crown rump length, or a firmly known last menstrual period date
There are many causes of IUGR with most of them relating to conditions related to the __________, _________, and ________ __________ _________
Uterus, placenta, and placental transfer rate
A decreasing uterine plasma volume is thought to be a ________ physiologic factor in IUGR
Major
What will happen to the developing fetus when it does not receive enough nutrition to provide for normal metabolic needs?
It won’t grow
Maternal conditions which may affect uterine plasma volume
Poor nutritional status Smoking, drug or alcohol abuse Multiple gestation severe anemia Diabetes Torch infection Chronic renal disease Severe chronic asthma RH sensitization Extremes of age under 17 or over 35 High altitude Heart disease
Placental conditions which may affect uterine plasma volume
Placental infarcts and hamangiomas/ chorioangiomas Small placenta Single umbilical artery Abruption Placental insufficiency
Fetal conditions which may affect uterine plasma volume
Chromosomal or genetic abnormalities
Intrauterime infection
Growth restricted fetuses are born with diminished stores of fat and glycogen and therefore, likely to be _________
Hypoglycemic
Nutritional support is needed until the infant ____________ it’s glycogen and fat deposits
increases
Clinical signs or IDGR include?
Uterus measuring small for dates
History of maternal condition which is associated with IUGR
IUGR can be ___________ or __________
Symmetric or asymmetric
Accounts for 25% Less common Affects the entire fetus Etiology is often genetic or due to maternal infection Onset may be earlier in gestation
Symmetric IUGR
Sono findings for Symmetric IUGR
All measurements are more than two wks below expected in the 2nd trimester or below three wks in the 3rd trimester
(remember the 1, 2, 3 rule about size in 1st, 2nd, and 3rd trimester)
Oligohydramnios
Low biophysical profile score
What are the two things that all measurements are based on?
either a firm LMP date or on a first trimester ultrasound
The __________ ___________ is usually consistent with dates when the other parameters are less than expected
transcerebellar diameter
Accounts for 75% or the vast majority of intrauterine growth retardation
Occurs usually in the last 8-10 wks of pregnancy
Asymmetric IUGR- brain sparing IUGR
____________ patterns in the fetus attempt to protect the fetal brain so it receives most of the nutrient rich blood first, and as a result, there is __________ between the head size and the abdominal size
Hemodynamic, Asymmetry
Ultrasound findings for Asymmetric IUGR
- The head to body ratio for HC/ AC ratio is greater than two standard deviations above normal
- The abdominal circumference measures greater than two weeks behind the head circumference
- Oligohydramnios
- *The head is of normal size and the abdomen is smaller
What Doppler technique has been proven as diagnostic for IUGR?
There is no single Doppler technique that has been proven as a diagnostic for IUGR
The predictive value of Doppler in IUGR has been shown to be, ?
low, 20-40%
Measurements of _________ ____________ resistance are the most widely accepted
Umbilical artery
Normally, there is a progressive decrease in the resistance in the umbilical artery during the course of
Pregnancy
Why is the umbilical artery low during pregnancy?
to make it easy for the fetus to get rid of wastes back to the placenta
Resistive index should be
less than 0.8
Systolic/ diastolic ratio greater than ______is considered abnormal after _______ wks
3.0, 30
Ratios can be higher if measured closer to the fetal cord insertion so they should be taken closer to the
Placental cord insertion
Absent or reverse flow in the umbilical artery is an
ominous sign
What is the proper technique to measure the resistance and the systolic/ diastolic ratio
have an angle of insonation as close to zero with respect to the umbilical artery (as parallel as possible to the artery)
Destruction of fetal red blood cells by antibodies with subsequent fetal or neonatal complications
Erythoblastosis fetalis
What are the causes of Erythroblastosis fetalis
RH incompatibility
ABQ incompatibility
Iso immune disease
other minor blood group incompatibilities
What are the clinical manifestations for erythroblastosis fetalis?
Congestive heart failure
Fetal death
Hydrops fetalis
An excessive accumulation of fluid in fetal tissues and body cavities. Interstitial edema, plural and pericardial effusion’s and ascites
Hydrops fetalis
Name the two types of hydrops
Immune hydrops
Nonimmune hydrops
- Secondary to Rh incompatibility (Rh isoimmunization)
- Occurs when Rh negative mother and an Rh positive father have a baby
- The fetus is Rh positive
- Maternal antibodies recognize Rh antigens on fetal blood cells as foreign
Immune hydrops
The maternal antibodies attack and destroy __________
Red blood cells
What does the destruction of red blood cells result in?
Erythroblastocysts fetalis
Fetal anemia, which results in hydrops
Fetal red blood cells generally do not cross the placenta so exposure of fetal cell to maternal circulation occurs at
Delivery,
abortion,
placental abruption,
hemorrhage, amniocentesis
During which pregnancy does the most trouble occur, due to maternal antibodies?
In the second pregnancy due to prior blood mixing after delivery of the first baby
What is given to the mother after each pregnancy and also after amniocentesis to prevent antibodies from forming, and to protect future pregnancies?
RhoGAM or Rh isoimmunization
Middle cerebral artery Doppler can help determine the likelyhood of ?
Fetal anemia
The MCA (middle cerebral artery) is examined close to its origin from the ?
Internal carotid artery
When measuring the MCA Doppler at what angle of the ultrasound beam and the direction of blood flow be?
0 degrees
The risk of anemia is highest in fetuses with a pre-transfusion peak systolic velocity of _______ times the median or higher
1.5
True or False
The fetal heart is pumping with a higher velocity and often, a higher rate in an effort to get oxygen to the tissues. Because the number of red blood cells is low, due to destruction the body compensates by doing this.
True
Red blood cell destruction
Hemolysis
A byproduct of the destruction of red blood cells
Bilirubin
The patient may need serial amniocentesis to determine if ____________ is occurring by testing the bilirubin levels in the amniotic fluid.
Hemolysis
What is more accurate for fetal anemia to determine if hemolysis is occurring?
Cordocentesis or percutaneous blood sampling (PUBS)
Intrauterine transfusions using ultrasound guidance can be performed to treat ___________, ideally after the onset of anemia but before the onset of fetal hydrops
anemia
Hydrops due to any other cause besides Rh sensitization
Non-immune hydrops
What are the causes of Non-immune hydrops?
Cardiac anomalies/ arrhythmia Infections like torch and fifths disease Chromosomal abnormalities Congenital blood disorders Twin/twin transfusion syndrome Abdominal or pulmonary masses which lead to venous obstruction
What are the Ultrasound findings in hydrops?
Pericardial effusion (earliest sign) Ascites Fetal skin thickening/edema/anasarca Placental thickening >5cm in AP dimensions Pleural effusions Hepatosplenomegally Polyhydramnios Enlarged umbilical vein, >1cm
Occurs during the second or third trimester,
Fetal demise
What does the sonographic appearance of fetal demise depend on?
It depends on when after the demise the fetus is examined`
What are the ultrasound findings of fetal demise?
Absent cardiac activity Exaggerated fetal position, flexion Roberts sign Spaulding sign Fetal maceration Duels sign/halo sign
Echogenic foci which represents gas in pulmonary vessels or in the abdomen, this is a delayed finding, occuring after a wk after demise
Roberts sign
Overlapping skull bones, also a delayed finding seen about a wk after demise
Spaulding sign
A halo seen radiographically secondary to subcutaneous scalp edema
Duels sign/ Halo sign
Oligohydramnios
Low biophysical profile score
