Fetal growth Flashcards
what is the Barker hypothesis?
this refers to the fetal origins of adult disease-disease in later life can be attributed to impaired fetal growth.
complications to the fetus associated with poorly controlled maternal diabetes?
macrosomia-may be birth trauma e.g. shoulder dystocia and brachial plexus injury
prematurity
impaired lung maturation, respiratory disorders of newborn
neonatal hypoglycaemia
cardiac problems
NTDs if conception occurs during a period of maternal hyperglycaemia
polycythaemia
RFs for fetal growth restriction?
maternal age-extremes low or high BMI smoking, alcohol, recreational drugs, and OTC e.g. atenolol previous FGR recurrent fetal loss raised AFP-indicates poor placental function previous unexplained still birth AI disease, antiphospholipid syndrome HTN renal disease haemoglobinopathies
major RFs for small for gestational age baby?
smoking-11 or more cigarettes per day maternal age over 40 maternal or paternal SGA previous SGA baby cocaine use daily vigorous exercise previous stillbirth renal disease chronic HTN diabetes with vascular disease antiphospholipid syndrome-anti-cardiolipin and lupus anticoagulant Abs, CLOT heavy bleeding similar to menses
antenatal care for women at risk of a SGA baby?
- if 1 major RF, serial US growth scans+assessment of fetal wellbeing with umbilical artery Doppler from 26-28wks-looking for end diastolic flow
- if 3 or more minor RFs, should have uterine artery Doppler at 20-24wks-assessment for women at risk.
- high risk populations should have uterine artery doppler at 20-24 wks
- if abnormal uterine artery doppler at 20-24 wks and/or notching, need r/f for serial US and umbilical artery doppler from 26-28wks
- if normal uterine artery doppler, should be offered 1 scan during 3rd trimester plus umbilical artery doppler
- serial US and umbilical artery doppler should also be offered in cases of fetal echogenic bowel.
investigations indicated for SGA fetuses?
- if severe SGA detected at fetal anomaly scan, r/f for detailed fetal anatomical survey and uterine artery doppler by fetal medicine specialist
- offer karyotyping if severe SGA and structural anomalies, and in those detected before 23wks, especially if normal uterine artery doppler
- infection screening-serological screening for congenital CMV and toxoplasmosis in severe SGA
- syphilis and malaria testing in high risk populations
primary surveillance tool for SGA fetus?
umbilical artery doppler
if abnormal flow indices and delivery not indicated, rpt twice a week when end diastolic velocities present, and daily if absent/reversed end diastolic velocities
how should amniotic fluid volume be interpreted in SGA fetuses?
based on single deepest vertical pocket
how should delivery be timed in a term SGA baby with a normal umbilical artery doppler?
an abnormal MCA doppler
if abnormal, delivery should be no later than 37wks
how is delivery timed in the preterm SGA fetus with an abnormal umbilical artery doppler?
ductus venosus doppler-used for surveillance and to time delivery
when is delivery recommended in a SGA fetus detected before 32 weeks gestation with absent or reversed end diastolic velocity on umbilical artery doppler?
when DV doppler becomes abnormal or umbilical vein pulsations appear, as long as fetus viable (after 26wks?) and antenatal corticosteroids have been completed
even if DV doppler normal, delivery recommended by 32wks, and should be considered between 30 and 32.
if abnormal umbilical artery doppler in SGA fetus detected after 32wks, when is delivery recommended?
no later than 37 weeks
mode of delivery for SGA fetus?
- C section if absent or reduced end diastolic velocity
- can induce labour if normal umbilical artery doppler or abnormal pulsatility index but end-diastolic velocities present, but higher rates of emergency C section, need continuous fetal HR monitoring from onset of contractions.
when can SFH start to be measured?
after 24 weeks gestation
define a small for dates fetus?
growth measurements are below the 10th population centile for gestational age.
