GTG 31 - small for gestational age fetus Flashcards
How is SGA defined?
EFW or AC <10th centile
How is low birth weight defined?
<2.5kg
Which patients require direct referral for serial scans?
Patients with 1 major risk factor for SGA and patients in who SFH cannot be accurately measured (large fibroids, BMI >35)
Which patients require uterine artery Doppler screening?
Patients with 3 or more minor risk factors for SGA
Which medical conditions are major risk factors for SGA?
APS
chronic hypertension
renal impairment
diabetes with vasculopathy
Is a history of PET, a major or minor risk factor for SGA?
Minor risk factor
Is a history of previous SGA, a major or minor risk factor for SGA?
Major risk factor
Is a maternal smoking history, a major or minor risk factor for SGA?
Dose dependent: 1-10/day = minor, >/= 11 = major
Is cocaine use, a major or minor risk factor for SGA?
Major risk factor
Which findings on screening (biochemical or anomaly) are major risk factors for SGA?
PAPP-A <0.4 MOM or fetal echogenic bowel
How does pregnancy interval influence risk of SGA?
<6 months or >60 months (5 years) are both minor risk factors for SGA
Is bleeding in early pregnancy, similar to a menstrual period, a risk factor for SGA?
Yes, major risk factor
How does maternal age influence risk of SGA?
> 40 years old = major risk factor, >35 years old = minor risk factor
How does BMI influence risk of SGA?
Underweight <20 = minor risk factor,
Overweight 25-34.9= minor risk factor for SGA,
obese >35 requires serial scanning because SFH inaccurate
Which medical conditions are not considered risk factors for SGA (in this guideline)?
Asthma, inflammatory bowel disease, thyroid disease. SLE = maybe, but insufficient evidence
When in the pregnancy should serial scans of fetal growth start?
26-28 weeks
When in the pregnancy should uterine artery Doppler be screened?
20-24 weeks (it should not be repeated – risk of SGA remains, even if it normalises)
What features would classify a uterine artery Doppler as abnormal?
PI >95th centile +/- notching
What is the odds ratio of an SGA baby with PAPP-A <0.4?
<10th centile = 2.7, <3rd centile = 3.6
How might SFH measurements lead to a growth scan referral?
SFH <10th centile on customised growth chart, or indication of FGR, however no evidence on the number of centiles that need to be crossed for a referral to be made
What time interval is recommended between growth scans to minimise false positive for FGR?
3 weeks between growth scans
What proportion of SGA pregnancies are associated with infection (which infections)?
5% - CMV, Toxoplasmosis, syphilis and malaria
What proportion of SGA pregnancies are associated with chromosomal abnormalities?
19% - triploidy most common <26/40, trisomy 18 most common >26/40
How should severe, early onset SGA be managed?
Severe SGA identified at 18-20/40 anomaly scan should be referred to FMU for detailed anatomy survey, uterine artery Doppler, consideration for karyotyping and serological screening
