Fetal growth Flashcards Preview

Obstetrics and Gynaecology > Fetal growth > Flashcards

Flashcards in Fetal growth Deck (28)
Loading flashcards...
1
Q

what is the Barker hypothesis?

A

this refers to the fetal origins of adult disease-disease in later life can be attributed to impaired fetal growth.

2
Q

complications to the fetus associated with poorly controlled maternal diabetes?

A

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

3
Q

RFs for fetal growth restriction?

A
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
4
Q

major RFs for small for gestational age baby?

A
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
5
Q

antenatal care for women at risk of a SGA baby?

A
  • 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.
6
Q

investigations indicated for SGA fetuses?

A
  • 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
7
Q

primary surveillance tool for SGA fetus?

A

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

8
Q

how should amniotic fluid volume be interpreted in SGA fetuses?

A

based on single deepest vertical pocket

9
Q

how should delivery be timed in a term SGA baby with a normal umbilical artery doppler?

A

an abnormal MCA doppler

if abnormal, delivery should be no later than 37wks

10
Q

how is delivery timed in the preterm SGA fetus with an abnormal umbilical artery doppler?

A

ductus venosus doppler-used for surveillance and to time delivery

11
Q

when is delivery recommended in a SGA fetus detected before 32 weeks gestation with absent or reversed end diastolic velocity on umbilical artery doppler?

A

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.

12
Q

if abnormal umbilical artery doppler in SGA fetus detected after 32wks, when is delivery recommended?

A

no later than 37 weeks

13
Q

mode of delivery for SGA fetus?

A
  • 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.
14
Q

when can SFH start to be measured?

A

after 24 weeks gestation

15
Q

define a small for dates fetus?

A

growth measurements are below the 10th population centile for gestational age.

16
Q

define a large for dates fetus?

A

growth measurements are above the 95th population centile for gestational age.

17
Q

when can the fundus 1st be palpated abdominally?

A

12 weeks gestation

18
Q

1st consideration when referred a small for dates baby?

A

is the baby actually small for dates?
so need to confirm number of weeks gestation-how was their weeks calculated-was it via their booking scan, and when was this done? (should be between 10 and 13+6 weeks)
so assess growth by US and r/v the measurements.

19
Q

causes of a confirmed small for dates baby?

A
  • normal small-constitutionally small, small parents
  • abnormal small-chromosomal abnormalities, genetic syndromes
  • infected small-most commonly CMV
  • starved small-placental FGR-smoking, multiple gestation, pre-eclampsia
  • wrong small-incorrect measurements or dates.
20
Q

how can successful trophoblast invasion to form a low resistance circulation be established?

A

uterine artery Doppler:

notching identifies high risk patients.

21
Q

additional sonographic measurements that can help differentiate between normal small and FGR?

A

symmetry
liquor volume
umbilical artery Doppler
MCA Doppler

22
Q

what ultrasonographic features would suggest a fetus with ‘placental’ IUGR?

A
  • growth often asymmetrical and growth velocity may be reduced
  • amniotic fluid may be reduced
  • high resistance umbilical artery flow, BPP score decreases (biophysical profile)-HR, RR, muscle tone, movements and amniotic fluid volume.
23
Q

fetal surveillence options in SGA baby?

A

-serial US for growth measurements every 2-4 weeks (NOT fetal well-being surveillence)
-fetal well being surveillence:
maternal perception of fetal movements
umbilical artery Doppler
amniotic fluid volume
biophysical profile

24
Q

management of a baby who is more than 34 weeks gestation and has absent or reversed end diastolic velocities on umbilical artery Doppler?

A

consider delivery

*if before 34 weeks, but also other abnormal parameters-CTG abnormal, BPP abnormal, or other Doppler parameters abnormal-MCA, umbilical vein.

25
Q

causes for large for dates baby?

A
maternal obesity
uterine fibroids
multiple gestation
molar pregnancy
fetal macrosomia
polyhydramnios
26
Q

risks for mother if large for dates baby?

A

prolonged labour
instrumental delivery
genital tract trauma
PPH

27
Q

risks for fetus if large for dates?

A
birth injury
perinatal asphyxia-hypoxic ischaemic encephalopathy-cerebral palsy
shoulder dystocia, Erbs palsy
hypoglycaemia
childhood obesity
metabolic syndrome
28
Q

markers on the abdomen that correlate to number of weeks gestation when palpating the fundus?

A

12 weeks-fundus just above the pubic symphysis.
24 weeks-reaches the umbilicus.
36 weeks-reaches the xiphisternum.