small and large for gestational age Flashcards
what is small for gestational age?
fetes that measures below the 10th centile for their GA
measured using:
estimated fatal weight (EFW)
fetal abdominal circumference (AC)
customised growth charts are used based on mom’s ethnic group, weight, height and parity
low birth weight <2500g
severe SGA <3rd centile
what are the causes of SGA?
- constitutionally small (appropriately matched mom and family)
- fatal growth restriction (intrauterine growth restriction) pathology / nutrients / oxygen
fatal growth restriction causes
- placenta mediated growth restriction
2. non-placenta mediated growth restriction
examples of placenta mediated growth restriction
conditions that affect the transfer of nutrients across the placenta
Idiopathic Pre-eclampsia Maternal smoking Maternal alcohol Anaemia Malnutrition Infection Maternal health conditions
non placenta mediated growth restriction
pathology of the fetus
Genetic abnormalities
Structural abnormalities
Fetal infection
Errors of metabolism
signs of fatal growth restriction
SGA Reduced amniotic fluid volume Abnormal Doppler studies Reduced fetal movements Abnormal CTGs
long term risk of SGA
Cardiovascular disease, particularly hypertension
Type 2 diabetes
Obesity
Mood and behavioural problems
risk factors of SGA
Previous SGA baby Obesity Smoking Diabetes Existing hypertension Pre-eclampsia Older mother (over 35 years) Multiple pregnancy Low pregnancy‑associated plasma protein‑A (PAPPA) Antepartum haemorrhage Antiphospholipid syndrome
how to monitor SGA
RCOG green top guidelines
low risk- monitor symphysis fundal heigh at every antenatal appointment from 24 weeks onwards to identify potential SGA. plot on growth chart
if <10th
Three or more minor risk factors
One or more major risk factors
Issues with measuring the symphysis fundal height (e.g. large fibroids or BMI > 35)
book for serial growth scans and umbilical artery doppler. the serial ultrasound scans will measure the EFW, abdominal circumference, umbilical arterial pulsatility index and amniotic fluid volume
management of SGA
aspirin if risk of pre-eclampsia
treat modifiable risks (stop smoking)
serial growth scans
early delivery where growth is static
BP, uterine artery doppler scanning, detail fetal anatomy, karyotyping, test for infections
early delivery
corticosteroids
large for gestational age
macrosomia
weight of newborn 4.5kg at birth
estimated fetal weight >90th centile
causes: Constitutional Maternal diabetes Previous macrosomia Maternal obesity or rapid weight gain Overdue Male baby
risk of LGA to mom and baby
mom: Shoulder dystocia Failure to progress Perineal tears Instrumental delivery or caesarean Postpartum haemorrhage Uterine rupture (rare)
baby: Birth injury (Erbs palsy, clavicular fracture, fetal distress and hypoxia) (shoulder dystocia) Neonatal hypoglycaemia Obesity in childhood and later life Type 2 diabetes in adulthood
management of macrosomia
USS to exclude polyhydramnios and estimate the fatal weight
OGTT for gestational diabetes
