Placenta And Intra-uterine Growth Restriction Flashcards
What is foetal growth restriction?
- failure of the foetus to achieve its predetermined growth potential
Foetal growth restriction (FGR) is the failure of the foetus to achieve its predetermined growth potential. What is the primary reason for this?
- placenta dysfunction
What is small for gestational age (SGA)?
- term used to describe a baby who is smaller than the usual amount for the number of weeks of pregnancy
- BUT not foetal growth restriction
Small for gestational age (SGA) is a term used to describe a baby who is smaller than the usual amount for the number of weeks of pregnancy, generally those in the <10 centile. What are the 2 methods commonly used to assess if the baby is SGA?
- estimated foetal weight
- abdominal circumference
Foetal growth restriction (FGR) is the failure of the foetus to achieve its predetermined growth potential, which is primarily caused by placenta dysfunction. What are the 2 types of FGR?
1 - symmetrical
2 - asymmetrical
Foetal growth restriction (FGR) is the failure of the foetus to achieve its predetermined growth potential, which is primarily caused by placenta dysfunction. There are 2 types of FGR, symmetrical and asymmetrical. What is symmetrical and asymmetrical FGR?
- symmetrical = small head and small abdomen (BUT everything is symmetrical)
- asymmetrical = normal head and small abdomen (NOT symmetrical)
What 3 measures are used to determine if foetal growth restriction (FGR) is present?
1 - size
2 - growth
3 - type
Assessing the size of the baby in pregnancy is crucial to assess if the baby has a small gestational age (SGA). What is the definition from the WHO on if a baby is SGA?
- <2500 grams or 2.5kg at birth
When assessing the growth of a foetus during pregnancy, why is it important to perform multiple observations?
- a dynamic and changing process
Foetal growth restriction (FGR) is the failure of the foetus to achieve its predetermined growth potential, which is primarily caused by placenta dysfunction. There are 2 types of FGR, symmetrical and asymmetrical:
- symmetrical = small head and small abdomen (BUT everything is symmetrical)
- asymmetrical = normal head and small abdomen (NOT symmetrical)
What are the 3 most common causes for symmetrical FGR?
1 - congenital/chromosomal abnormalities
2 - intrauterine infections
3 - environmental factors
Foetal growth restriction (FGR) is the failure of the foetus to achieve its predetermined growth potential, which is primarily caused by placenta dysfunction. There are 2 types of FGR, symmetrical and asymmetrical:
- symmetrical = small head and small abdomen (BUT everything is symmetrical)
- asymmetrical = normal head and small abdomen (NOT symmetrical)
What is common causes for asymmetrical FGR?
- pathology associated with pregnancy (delayed onset)
- pre-eclampsia (high BP and coagulation issues), essential hypertension
What are some of the risk factors associated with an increased risk of small gestational age?
- asian/Indian ethnicity
- low BMI and maternal weight gain
- nulliparity (1st pregnancy)
- daily vigorous exercise
- maternal exposure to caffeine
- one baby at one time
A woman attends her GP for pre-conception counselling because the first child was born small for gestational age (SGA). What intervention is significant in reducing risk of SGA foetus in those with risk factors?
1 - Progesterone 2 - Dietary modification 3 - Calcium supplements 4 - Smoking cessation 5 - Anti platelets
4 - Smoking cessation
In non-pregnant women there are a number of different blood vessels that supply the uterus. However, once the placenta has formed, angiogenesis begins and 3 types of arteries develop within the placenta. What are these 3 blood vessels called?
1 - arcuate arteries
2 - uterine arteries
3 - spiral arteries
What cell that is derived from the blastocyst forms the placenta?
- trophoblasts
What is the most common finding in stillborn babies?
- foetal growth restriction
If a baby is born and has foetal growth restrictions what are some of the acute conditions they may develop?
- necrotising enterocolitis
- low apgar scores (score based on vitals)
- hypoxic brain injury
- respiratory support
- chronic lung disease
- retinopathy
- prolonged neonatal intensive care unit
If a baby is born and has foetal growth restrictions what are some of the chronic conditions they may develop?
- metabolic electrolyte imbalance
- failure to thrive
- learning difficulties
- short stature
- cerebral palsy
- mental handicap
What condition is evident from the data in the figure below?
- baby with foetal growth restriction (FGR)
The data in the figure below demonstrates a baby with foetal growth restriction (FGR). What imaging would have provided the measurements presented here?
- serial ultrasound scans
What is the gold standard for antenatal care that is used to identify foetal growth restriction?
- serial ultrasound with doppler scans
Abdominal palpation can be used to identify the foetal size to identify if the foetus is at risk of foetal growth restriction. What is the detection rate of this method?
- 30%
- can be difficult in early and late pregnancy
A measurement from the symphysis to the fundus, provides fundal height with abdominal girth. What are the detection rates for this in detecting foetal growth restriction?
- 20-80% detection rate
- does not improve perinatal outcome
What imaging modalities are currently used to try and detect foetal growth restriction?
- serial ultrasound (amniotic fluid volume) (poor predictive value)
- serial ultrasound with doppler imaging (gold standard)
- umbilical dopplers (poor predictive value)
Cardiotocography (CTG) is a technique that can be used to detect if a foetus is at risk of foetal growth restriction. What is CTG?
- instrument that can detect foetal HR and uterine contractions
When assessing foetal well being, in addition to imaging modalities, we can determine the foetus biophysical profile. What 5 measurements are included in this profile?
- cardiotocography (HR and uterine contractions)
- foetal breathing movements (ultrasound)
- foetal body movements (ultrasound)
- liquor volume (amniotic fluid volume)
- foetal growth
When assessing foetal well being, in addition to imaging modalities, we can determine the foetus biophysical profile. The following 5 measurements are included in this profile:
- cardiotocography (HR and uterine contractions)
- foetal breathing movements (ultrasound)
- foetal body movements (ultrasound)
- liquor volume (amniotic fluid volume)
- foetal growth
What is the purpose of utilising the biophysical profile in relation to foetal growth restriction (FGR)?
- identify foetus at risk of FGR and therefore hypoxia
- rule out just small babies without FGR
How can the diagnosis of a foetus that is at risk of foetal growth restriction be optimised?
- use customised foetal growth charts
- use 2 measures of abdominal circumference and estimated foetal weight at least 3 weeks apart
In a normal pregnancy, does the blood flowing from the mother through the umbilical cord blood vessels (umbiliical artery and vein) have any resistance?
- no
- placenta acts as a sponge, from there it delivers oxygenated blood to the foetus
What is placenta infarction?
- interruption of blood supply to a part of the placenta
- normally in the umbilical artery
- lack of blood causes hypoxia and ischaemia
- cells of the placenta can die
In a pregnancy where there is placenta infarction, which is interruption of blood supply to a part of the placenta, causing its cells to die, is there a resistance to blood flow to the foetus?
- placenta acts as a wall
- blood is unable to reach the foetus and reflects back along the umbilical artery
What method can be used to detect blood flow velocity in foetal and placenta vessels?
- ultrasound doppler
When detecting blood flow velocity in foetal and placenta vessels using ultrasound doppler, what would a reduced end diastolic flow suggest?
- placenta has high resistance and is failing
- baby can become hypoxic
Does the growth chart show foetal growth restriction or small gestational age?
- small gestational age
- plot is consistent and does not move between deciles
Does the growth chart show foetal restriction growth or small gestational age?
- foetal growth restriction
- begins in 9th percentile, but drop between deciles
In the growth chart below, we can see that the top figure demonstrates a small gestational baby and the bottom chart shows a foetal growth restriction. Of the 2 which baby may need to be delivered prematurely?
- foetal growth restriction
- the placenta may be failing the baby is malnourished and/or hypoxic
In asymmetrical foetal growth restriction there is generally a larger head and/or organs compared to the abdomen, as seen in the image below. Why do some organs develop more than others?
- the body adapts to lack of nutrient and hypoxia
- for example the brain sparing effect as the foetus redistributes blood to the more critical tissues (liver, kidneys etc…)
In the brain sparing effect that we observe in the asymmetrical foetal growth restriction, is the head circumference (HC) or abdomen circumference (AC) normally bigger?
- normally head is bigger
- AC < HC
What is Pregnancy Associated Plasma Protein-A (PAPP-A)?
- a hormone that made by the placenta (afterbirth) in pregnancy
- secreted by the placenta to maintain placenta development
Pregnancy Associated Plasma Protein-A (PAPP-A) is a hormone that made by the placenta (afterbirth) in pregnancy secreted by the placenta to maintain placenta development. What can low levels of this indicate?
- foetal growth restriction
What do the uterine and spiral arteries provide a blood supply to?
- uterine arteries = uterine
- spiral arteries = endometrium (generally lost during periods)
What is the Barkers hypothesis?
- adverse nutrition in early life including foetal growth restriction can increase risk of metabolic syndrome (obesity, diabetes, insulin insensitivity, hypertension, hyperlipidemia, coronary heart disease)
If a baby is detected as having an abnormal blood flow to the placenta using ultrasound doppler, how many weeks should the baby be delivered?
- <32 weeks
- better to be in NICU than in a uterus with restricted blood flow to the placenta
You are counselling a 16 week gestation primiparous woman regarding her results which suggest a low PAPP-A level.Which is the only form of surveillance that, when used alone, has been shown to reduce perinatal morbidity and mortality in a high-risk population?
1 - Foetal movement monitoring 2 - USS assessment of liquor volume 3 - CTG cardiotocography 4 - Biophysical profile scoring 5 - Umbilical artery doppler
5 - Umbilical artery doppler
