PBL 2 Flashcards
Symphysis-fundal height Definition
distance between the pubic symphysis and the fundus
when is a baby deemed to be small
A baby is deemed to be “small-for-gestational age” at birth if it weighs less than the tenth percentile for the appropriate gestation
what are the causes of intrauterine growth restriction
In most cases the cause is unknown, and may simply represent the lower end of the normal range.
Specific Causes
• Pre-eclampsia.
• Congenital or chromosomal abnormalities.
• Infections (e.g. rubella, cytomegalovirus, toxoplasmosis, syphilis)
• “Placental insufficiency”.
o Minor disturbance of placentation in early pregnancy.
what are the risk factors in the mother that can lead to intrauterine growth restriction
- Alcohol abuse.
- Clotting disorders
- Drug Addiction
- High Blood Pressure or Heart Disease
- Kidney Disease
- Poor Nutrition.
what does intrauterine growth restriction increase the risk of
- Intrapartum fetal distress.
- Intrapartum asphyxia (hypoxia)
- Postnatal hypoglycaemia.
- Impaired neurodevelopment.
- Intrauterine death.
- (Possible) type 2 diabetes and hypertension in adult life.
How do you assess the fundal height
• Distance from the pubic bone (symphysis pubis) to the top of the uterus (fundus) (+- 2m).
o Symphysio-fundal height.
what does the fundal heigh correspond to
corresponds to gestational age in weeks
what is the negative of a fundal height
• Directly not an accurate measure of fetal growth.
o Gives a crude estimate only in serial measurements.
what does ultrasound measure
• Estimates of fetal weight in utero (and therefore production in birth weight)
what measurements is the fetal weight in ultrasound derived from
o Biparietal diameter (BPD)
o Head circumference (HC)
o Trans-abdominal circumference (AC).
o Femur Length (FL).
what is the percentage error in ultrasound measurements and assessment of fundal height
• The error of each of these estimates is 16% (2SD) if gestation is known.
what are estimates of sensitivity of ultrasound
• Estimates of sensitivity (ability to determine case directly) of ultrasound in respect to growth retardation (birthweight less than 10th percentile) range from 40% to 80%.
o There is a high incidence of false positive results.
what are the two types of intrauterine growth restriction for BPD
Sudden Deviation from previously normal pattern.
Parallel but Lower: growth at lower range than value
what is a better measurement than BPD
A better index is the HC and AC.
what are the two types of intrauterine growth restriction using HC and AC
Symmetrical IGUR
Asymmetrical IGUR
describe symmetrical IUGR
Symmetrical IUGR: where both the HC and AC.
• Maintaining a ratio HC: AC of 1.
what are the causes of symmetrical IUGR
- Racial programming
- Congenital abnormalities such as karyotype problems
- Early pregnancy damage (due to infections/toxins).
describe asymmetrical IUGR
- Brain growth (HC) is preserved at the expense of the liver (AC).
- Ratio HC:AC less or equal to one.
What are the causes of asymmetrical IUGR
• Placental Insufficiency chronic hypoxia.
o Pre-eclampsia
o Smokers
o Diabetes
what are the other tests that you can carry out
- Fetal movements.
- Antepartum cardiotocogarphy (CTG)
- Measurement of amniotic fluid volume.
- Measurement of fetal breathing movements.
- Doppler blood-flow studies of umbilical and fetal cerebral arteries.
How do you manage a growth restricted baby
• Intensification of existing antenatal care (including serial repetition of various tests).
- can early deliver in serious cases
How is early delivery done
- Done through induction or C-section.
* Course of glucocorticoid injections given to mother at least 24 hours before delivery.
what is the benefits of early delivery
o Improves fetal outcome/reduce perinatal complications of prematurity.
o Enhances fetal lung maturity (stimulates surfactant production)
o Protects fetus from intracranial haemorrhages
o Protects from necrotizing enterocolitis.
what happens in an extremely low birth weight
Extremely low birth weight = high risk of perinatal mortality and neonatal morbidity.
• Possible increased CAD, hypertension and type 2 diabetes later in life (Barker Hypothesis).
