Foetal Growth Restriction Flashcards
Define Fatal growth restriction (FGR)
Failure of the fetus to achieve its predetermined growth potential for various reasons
Define small gestational age (SGA)
Birth weight <10th centile
Describe low birthweight babies
Most LBW neonates are NOT growth restricted
Many FGR babies are delivered prematurely
3-10 fold increase in perinatal morbidity and mortality
LBW, FGR and preterm delivery have closely associated pathologies
Which centile is the most sensitive
10th is the most sensitive
The tenth centile will capture all babies with FGR, but will also include those babies that are just small for gestational age, i.e. you get a number of false positives.
Which centile is the most specific
3rd is the most specific
All babies recorded using the third centile will have FGR, but some FGR babies may be missed, i.e you get a number of false negatives.
What is the difference between gestational age and foetal age
GA is 2 weeks greater than FA. FA starts post fertilisation
What is the most common factor identified in stillborn babies
Intrauterine growth restriction (IUGR)
What are the consequences of Intrauterine growth restriction (IUGR)
it has serious consequences for babies who survive.
There is an increased risk of IUGR and intrauterine death (IUD) in mother’s subsequent pregnancy.
What are the short term problems of LBW/FGR
Respiratory distress Intraventricular haemorrhage Sepsis Hypoglycaemia Necrotising enterocolitis Jaundice Electrolyte imbalance
What are the medium term problems of LBW/FGR
Respiratory problems
Developmental delay
Special needs schooling
What are the long term problems of LBW/FGR
Foetal programming
What are the maternal causative factors of FGR
Smoking Diabetes Anaemia <16 >25
What are the foetal causative factors of FGR
Multiple pregnancy
Chromosome abnormality
Inborn errors of metabolism
Which weeks are the period of placentation
10-12 weeks
Describe the placenta as an endocrine organ
Produces protein-peptides and steroid hormones and functions as a “transient hypothalamo-pituitary-gonadal axis”
What are the functions of the placenta
Maintains immunological distance between mother and fetus
Responsible for exchange of nutrients, gases + metabolic waste products between maternal and fetal circulation
Define pre-eclampsia
Multisystem disease that usually manifests as hypertension and proteinuria
BP > 140/90mmHg
Proteinuria > 0.3g/24hour (PCR>30)
Describe the development of the placenta
- Cytotrophoblast (CTB) invade syncytial (STB) and form villi which attach to the endometrium
- The CTB continues to grow forming a CTB shell which forms the placenta. 3. The villi grow deeper into the myometrium until they come into contact with maternal spiral arteries
- Spiral artery remodelling: CTB invade these arteries and cause them to become wider.
How does pre-eclampsia lead to IUGR
Normal exchange of nutrients is not possible
Due to inappropriate spiral artery remodelling
Which foetuses need growth monitoring
bad maternal obstetric history
Concerns in index pregnancy
What may constitute a bad obstetric history
Previous maternal hypertension
Previous FGR
Stillbirth
Placental Abruption
What may cause concern in index pregnancy
Abnormal serum biochemistry (PAPP-A < 0.3)
Reduced symphysis fundal height
Maternal systemic disease e.g. hypertension, renal, coagulation
Antepartum haemorrhage
When is screening of “at risk” pregnancies carried out
24 weeks
What is screened for in “at risk” pregnancies
PAPP-A < 0.3 MoM
POHxPET/FGR
Maternal systemic disease e.g. HT< renal, sickle
Uterine artery Doppler in 1st/2nd trimester (blood flow in uterine arteries -> find high resistance flow)
When is delivery aimed for
≥28 weeks
and / or ≥500g
Describe the delivery in pregnancies complicated by FGR
Timing delivery in these pregnancies depends on balancing the risks to the fetus if it remains in utero and the hazards from the prematurity, which decrease as the gestation advances
What is required if the baby is born less than 36 weeks
Corticosteroids
Is late IUGR or early IUGR easier to manage
Late
Early IUGR: 1%, usually linked to maternal disease e.g. PEC, difficult to manage because of risk of prematurity
Late IUGR: 5-7%, rarely linked to PEC, difficult to differentiate from SGA, easily managed by delivery
Describe the growth of the baby if a dating problem is the cause of SGA
Consistent growth
Normal dopplers and fluid
Describe normal growth
Growth may reduce in 2 weeks
Normal dopplers and fluid
Describe the growth of the baby if SGA is caused by a foetal problem
Fetal abnormality
Describe the growth of the baby if placental insufficiency is caused by a foetal problem
Reduction in AC/FL
Reduced liquor
Deranged doppler
