Fetal growth and size at birth Flashcards
> 4000g
macrosomic
2500g - 4000g
normal birth weight
1500g- 24999g
low birth weight (LBW)
1000g- 1499g
very low birth weight (VLBW)
<1000g
Extremely
Low Birth
Weight
(ELBW)
four categories that affect birth weight
genetics
gestational age
fetal nutrition and placental function
environmental factors
genetics
Some infants are constitutionally destined to be larger than others
gestational age
Fetuses normally grow with age
environmental factors
alcohol
chronic infections
if an infant has a low birth weight they may be
- Constitutionally small.
- Preterm.
- Suffering from poor fetal nutrition.
- Damaged by environmental factors.
One can describe the weight with respect to the gestational age in terms of whether
the child is:
- Large (overweight) for Gestational Age (LGA): >90th centile on Intergrowth charts.
- Appropriate for Gestational Age (AGA) (10th to 90th centile).
- Small (underweight)for Gestational Age (SGA) <10th centile.
What does the term IUGR describe in relation to a fetus?
The term Intra-Uterine Growth Restriction (IUGR) describes a fetus who grows slower than normal, often from early pregnancy.
Aetiology of underweight for gestational age: Maternal
. Maternal
* Teenager/Advanced Maternal Age.
* Short birth interval.
* Maternal undernutrition.
* Maternal diseases including hypertension, diabetes, cardiac and renal disease,
malaria, TB and advanced HIV.
Aetiology of underweight for gestational age: Uterovascular inadequacy
- Abruption.
- Pre-eclampsia.
- Multiple Pregnancy.
Aetiology of underweight for gestational age: Environmental
- Cigarettes.
- Alcohol.
- Illicit drugs.
- Licit drugs
Aetiology of underweight for gestational age: Fetal
- Chromosomal abnormalities.
- Genetic diseases.
- Intrauterine infections (TORCH).
- Inborn errors of Metabolism (IEM).
- Twin to twin transfusion.
What is Intra-Uterine Growth Restriction (IUGR)?
IUGR describes a fetus who grows slower than normal, often from early pregnancy.
What is the characteristic growth pattern of infants affected by a late insult, such as pre-eclampsia?
Infants affected by a late insult experience acute starvation, leading to wasting and a small abdominal circumference.
What is the term used for a fetus who has been growing well but suffers a late insult, like pre-eclampsia?
Such fetuses are termed acutely starved and may exhibit asymmetrical growth patterns.
What happens to infants affected by a late insult, resembling those with Severe Acute Malnutrition (SAM)?
They become wasted with a small abdominal circumference due to depleted fat and glycogen stores.
Why do these infants appear asymmetrical at birth?
Their head and length remain appropriate, but their body appears relatively smaller due to wasting.
What is the potential outcome for these infants if fed appropriately after delivery?
They may experience good “catch-up growth” after birth.
What characterizes infants affected by growth restriction that starts early in fetal life?
They exhibit symmetrical growth restriction, affecting all organs, and are typically small at birth.
What distinguishes these infants from constitutionally small infants?
They may have severe concomitant pathology, such as chromosomal abnormalities or intra-uterine infections.
What is the long-term prognosis for infants affected by early fetal growth restriction?
They do not typically experience good catch-up growth and tend to have worse long-term outcomes compared to constitutionally small infants.
Complications of being underweight for gestational age
Some of the problems these infants face include:
* Hypoxic Ishaemic Encephalopathy.
* Meconium aspiration.
* Persistent Pulmonary Hypertension of the Newborn.
* Hypothermia.
* Hypoglycaemia.
* NEC
* Polycythaemia and jaundice.
* Cerebral Palsy, IVH and adverse neuro-developmental outcomes.
What is the Barker’s hypothesis, also known as the Fetal Origins Hypothesis?
It suggests that being growth restricted as an infant has lifelong effects on health.
What are some of the long-term health risks associated with being growth restricted as a fetus?
Growth-restricted fetuses have an increased risk of hypertension, diabetes, dyslipidemia, obesity, and ischemic heart disease when they reach adulthood.
