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
How should SGA babies with a normal UAD be monitored?
Two weekly AC, EFW, UAD and MCA after 32 weeks
When should SGA babies with consistent growth and normal serial measurements UAD and MCA be delivered?
Offer delivery by 37/40
When should SGA babies with static growth over 3 weeks with a normal UAD or a raised PI but EDF is present be delivered?
Consider delivery >34/40
When should SGA babies with normal UAD but an MCA <5th centile be delivered?
Recommend delivery by 37/40
How should SGA babies high UAD PI but EDF is present be monitored?
Weekly AC and EFW, twice weekly UAD
When should SGA babies with high UAD PI but EDF is present be delivered?
Delivery recommended by 37/40
How should SGA babies with absent or reversed end diastolic flow in UAD be monitored?
If baby is <32/40, they will need weekly AC and EFW and daily UAD, DV or computerised CTG
If baby >32/40, they will likely need delivery
When should SGA babies with absent or reversed end diastolic flow in UAD be delivered?
If DV or CTG abnormal, deliver before 32 weeks - Once viable (>24/40 or >500g) and steroid mature
If DV normal, recommend delivery by 32/40 and consider delivery 30-32/40
What is the perinatal mortality associated with AREDV in the UAD?
12%
What is the perinatal mortality associated with high PI or absent/reverse a wave in DV?
High Pi = 39%, absent/reversed a wave = 41%
What is considered abnormal variability on computerised CTG?
<3m/s
