Prematurity/ IUGR Flashcards
define low birthweight?
birthweight less than 2500g
define preterm baby?
baby born less than 37 weeks gestation
define extremely preterm baby?
baby born less than 28 weeks gestation
define very low birthweight?
birthweight less than 1500g
define ‘small for gestational age’?
birthweight less than 10th centile for age and gender
what are some causes of babies who are small for gestational age?
maternal factors- CHD, HT, renal disorders, drugs, malnutrition, smoking etc
fetal factors- congenital infections, chromosomal abnormalities (trisomy 18), structural malformations
placental factors- multiple pregnancies (twin twin transfusion syndrome), preeclampsia, thrombophilia, placental insufficiency
what does twin-twin transfusion syndrome refer to?
unequal sharing of uteroplacental vascularity between twins
what is the most common cause of preterm birth?
idiopathic- no known cause
what are some known causes of preterm birth?
premature rupture of membranes Cervical incompetence Multiple pregnancies Uterine anomalies antepartum haemorrhage
define IUGR?
failure of the fetus to achieve its growth potential
why is UPD (uniparental disomy) bad for fetuses?
inheritance of both chromosomes from one parent–> increased risk of autosomal recessive diseases
what perinatal infections can cause IUGR and how would you prevent them?
-CMV and toxoplasmosis are the two infections which cause IUGR
prevent CMV and toxo with good handwashing!!
avoid gardening and stray cats for toxoplasmosis
what are some ways we can detect IUGR?
Symphyseal-Fundal Height (SFH) MEASUREMENT
Ultrasound at 34 weeks, look at abdominal circumference of baby but not routinely done unless high clinical suspicion
you look at an ultrasound and notice that the foetus appears small. how might you exclude small foetus due to genetics rather than IUGR?
Parental small stature, absence of recognised risk factors, symmetrically small, normal growth trajectory, normal amniotic fluid, normal umbilical and other Doppler studies
if a baby is born prior to 30 weeks, what must we give the baby urgently??
CORTICOSTEROIDS IF LUNG IMMATURITY, + NEUROPROTECTION WITH MAGNESIUM SULFATE
what is your general management of IUGR?
- Confirm the diagnosis- IUGR or genetically small? (do an u/s and look at features that may indicate the fetus is meant to be genetically small
- Look for a cause- take a good history!! Then Ix: tertiary U/s, FBE, UEC, anti-phospholipid syndrome, congenital thrombophilia, serology etc
Karyotyping! - Fetal surveillance- cardiotography and ultrasound
- Any treatment can we offer?? not much of the way of treatment
- Deliver the baby according to risk benefit analysis; e.g. emergency c section if signs of fetal hypoxia
why might we perform an expensive karyotype of a fetus with IUGR?
karyotyping –> avoid unnecessary emergency caesarean for fetal distress;
psychological effects for parents
?termination, if the prognosis isn’t apparent in late pregnancy e.g. CMV infection; twins discordant for fetal abnormality
what are some causes of preterm labour?
pre-eclampsia perinatal infection premature rupture of membranes smoking antepartum haemorrhage