Small dates for pregn. Flashcards
Why small baby?
- pre- term delivery
Small for gestational age:
1. IUGR/FGR
2. constitutionally small
When is a preterm delivery ?
<37 wks
Extreme pre-term? 24-27+6
Very pre-term? 28-31+6
Moderate to late: 32-36+6
What is the survival rate of a 23 weeks birth?
20% chance of survival
What is the survival for a bby born beyond 32 weeks vs 26 weeks?
> 95%
26 weeks- 77%
Etiology of pre-term births?
Infection
‘Over distension’:
-Multiple
=Polyhydramnios
Vascular:
-Placental abruption
Intercurrent illness:
- Pyelonephritis / UTI
- Appendicitis
- Pneumonia
Cervical Incompetence
Idiopathic
How to label a SGA fetus?
- fetal weight or abdominal circumference is BELOW the 10th centile
- IUGR/ FGR
- LBW (below 2.5 kg) —-regardless of gestation
What can growth restriction be divided into?
Symmetrical: small head and small body
Asymp: normal size head and small body
Why are uterine artery dopplers performed?
- resistance of uterine artery is measured at 20 weeks
- —–presence of resisytance: HIGH RISK OF PRE-ECLAMPSIA and SMALL bby
Why are uterine artery dopplers performed?
- —–presence of resistance
- chewck the risk of hypertensive disease in pregnancy and risk of SGA
Fetal factors for small birth baby?
- infection (Rubella, CMV, Toxoplasmosis)
- congenital anomalies (absent kidneys)
- chromosomal abnormalities (Down $)
What are the clinical features of Poor growth?
- reduced fetal movements
- reduced SFH than expects
- reduced liquor
- predisposing factors
What is referred to as Biophysical profile?
- ## ultrasound assessment of the baby (combined with CTG)
- baby is scored on the presence of MOVEMENT/ TONE/ fetal breathing/ Liquor volume
—–score out of 10
What does the uterine artery doppler demonstrate, if there is developing HIGH resistance to the fetus?
- points where the blood flow is REVERSED; so baby is not recieving as much blood (just a little)
- absent flow during diastole (should NOT occur)
Any medications given to preterm babies?
- steroid: to promote fetal LUNG maturity
(if delivery is before 36 wks) - Magnesium sulphate (fetal neuroprotection against cerebral palsy, if before 32 weeks)
What are the risk factors for a pre-term baby?
- previous PTL (40% if 2x)
- Multiple
- Uterine anomalies
- Age (teenagers)
- Parity (=0 or >5)
- ehtnicity
- poor socio-econommic statur
- smoking
- Drugs (cocaine)
- Low BMI (<20)
Why do multiple pregnancies at once, increase the risk of a preterm birth?
- due to overdistension of the uterus
- complications may also contribute
25% of pre-term birth is planned c-section. Why plan a c-section?
- severe pre-eclampsia
- kidney disease
- poor fetal development
MAjority of pre-term is d/t this…..
UNKNOWN CAUSE (40%)
25% of pre-term birth is d/t an emergency event.
- placental abruption
- infection
- eclampsia (seizures)
What is considered to be small for gestational age ?
- EFW or AC is below the 10th centile (in the popn centile and the customised centiles)
What is the difference between IUGR and SGA?
- IUGR: bby starts on 50th centile and then cross centiles ending up on 20th over time = FAILURE to achieve true growth potential
- SGA: may grow on the 9th centile but they continue to follow their centile curve
Why may symmetrical growth restriction occur vs asymmetrical GR?
- possible chromosomal abnormality
- in utero infection
- congenital
- environmental
Asymm: placental reasons (baby is diverting blood to HEAD - to protect brain growth)
- smoking
Major risk factors for SGA baby?
oldmom/smoker/parental SGA /cocaine/Daily vigorous exercise/previous-stillbirth,SGA/diabetes/renal impariment/APS/heavy bleeding in pregnancy/low PAPP-A/ BMI>35/ fetal echogenic bowel
When is a growth scan indicated for a pregnancy?
- after a single measurement (even 2 or 3) plots below the 10th centile= suggests slow/ static growth
