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Flashcards in Small dates for pregn. Deck (45)
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1
Q

Why small baby?

A
  • pre- term delivery
    Small for gestational age:
    1. IUGR/FGR
    2. constitutionally small
2
Q

When is a preterm delivery ?

A

<37 wks
Extreme pre-term? 24-27+6
Very pre-term? 28-31+6
Moderate to late: 32-36+6

3
Q

What is the survival rate of a 23 weeks birth?

A

20% chance of survival

4
Q

What is the survival for a bby born beyond 32 weeks vs 26 weeks?

A

> 95%

26 weeks- 77%

5
Q

Etiology of pre-term births?

A

Infection

‘Over distension’:
-Multiple
=Polyhydramnios

Vascular:
-Placental abruption

Intercurrent illness:

  • Pyelonephritis / UTI
  • Appendicitis
  • Pneumonia

Cervical Incompetence
Idiopathic

6
Q

How to label a SGA fetus?

A
  • fetal weight or abdominal circumference is BELOW the 10th centile
  • IUGR/ FGR
  • LBW (below 2.5 kg) —-regardless of gestation
7
Q

What can growth restriction be divided into?

A

Symmetrical: small head and small body

Asymp: normal size head and small body

8
Q

Why are uterine artery dopplers performed?

A
  • resistance of uterine artery is measured at 20 weeks

- —–presence of resisytance: HIGH RISK OF PRE-ECLAMPSIA and SMALL bby

9
Q

Why are uterine artery dopplers performed?

A
  • —–presence of resistance

- chewck the risk of hypertensive disease in pregnancy and risk of SGA

10
Q

Fetal factors for small birth baby?

A
  • infection (Rubella, CMV, Toxoplasmosis)
  • congenital anomalies (absent kidneys)
  • chromosomal abnormalities (Down $)
11
Q

What are the clinical features of Poor growth?

A
  • reduced fetal movements
  • reduced SFH than expects
  • reduced liquor
  • predisposing factors
12
Q

What is referred to as Biophysical profile?

A
  • ## 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

13
Q

What does the uterine artery doppler demonstrate, if there is developing HIGH resistance to the fetus?

A
  • 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)
14
Q

Any medications given to preterm babies?

A
  • steroid: to promote fetal LUNG maturity
    (if delivery is before 36 wks)
  • Magnesium sulphate (fetal neuroprotection against cerebral palsy, if before 32 weeks)
15
Q

What are the risk factors for a pre-term baby?

A
  1. previous PTL (40% if 2x)
  2. Multiple
  3. Uterine anomalies
  4. Age (teenagers)
  5. Parity (=0 or >5)
  6. ehtnicity
  7. poor socio-econommic statur
  8. smoking
  9. Drugs (cocaine)
  10. Low BMI (<20)
16
Q

Why do multiple pregnancies at once, increase the risk of a preterm birth?

A
  • due to overdistension of the uterus

- complications may also contribute

17
Q

25% of pre-term birth is planned c-section. Why plan a c-section?

A
  • severe pre-eclampsia
  • kidney disease
  • poor fetal development
18
Q

MAjority of pre-term is d/t this…..

A

UNKNOWN CAUSE (40%)

19
Q

25% of pre-term birth is d/t an emergency event.

A
  • placental abruption
  • infection
  • eclampsia (seizures)
20
Q

What is considered to be small for gestational age ?

A
  • EFW or AC is below the 10th centile (in the popn centile and the customised centiles)
21
Q

What is the difference between IUGR and SGA?

A
  • 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
22
Q

Why may symmetrical growth restriction occur vs asymmetrical GR?

A
  • possible chromosomal abnormality
  • in utero infection
  • congenital
  • environmental

Asymm: placental reasons (baby is diverting blood to HEAD - to protect brain growth)
- smoking

23
Q

Major risk factors for SGA baby?

A

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

24
Q

When is a growth scan indicated for a pregnancy?

A
  • after a single measurement (even 2 or 3) plots below the 10th centile= suggests slow/ static growth
25
Q

How to diagnose SGA?

A
  • measuring fetal abdominal circumference
  • Combine with Head circumference +/- femur length to give EFW
  • Additional info from the scan= liquor volum/ amniotic fluid index-fluid around baby if low (sick baby)/ dopplers
26
Q

Why may there be high resistance in the uterine artery?

A
  • d.t abnormal placentation; failure of spiral artery invasion
27
Q

Once the fetal weight is estimated, what is then done?

A
  • value is plotted on customized growth charts
  • —guides you; whether or not the bby is at risk of SGA
  • —–with serial scans can see if the baby is following ITS PERCENTILE- determines if its at
28
Q

Maternal factors that cause SGA?

A
  • Smoking/alcohol/drugs
  • heightand weight
  • age
  • maternal disease (hypertension)
29
Q

When do the ladies have their uterine artery dopplers performed?

A
  • at their 20 weeks scan
30
Q

What are placental factors for SGA?

A
  • infarctions
  • abruption
  • IIary to hypertension

—-abnormally functioning placenta results in growth restriction or FAILURE

31
Q

If SGA/FGR is suspected from early on in the pregnancy; what is thought to be the cause?

A
  • chromosomal abnormality
32
Q

What are the postnatal consequences of IUGR?

A
  • hypoglycemia
  • effects of asphyxia
  • hypothermia
  • polycythaemia
  • hyperbilirubinemia
  • abnormal neurodevelopment
33
Q

Antenatal consequence of IUGR baby?

A
  • risk of HYPOXIA and or DEATH
34
Q

Why is it important to identify a SGA baby ?

A
  • risk of still birth

- following delivery of these babies; additional support in the neonatal unit may be needed

35
Q

Any affect on the SGA baby’s adult hood?

A
  • ongoing support in cases of cerebral palsy or developmental delay
36
Q

What combination of measures help assess the fetal well-being?

A
  • assessment of growth
  • cardiotocography
  • biophysical assessment
  • doppler usg
37
Q

Which baby will have serial scans for growth?

A
  • any baby with AC or EFW below the 10th centile
38
Q

Can blood flow within the baby be picked up?

A
  • yes

- mainly in its middle cerebral artery and the ductus venous flow

39
Q

How may a change in the MCA resistance suggest fetal compromise?

A
  • if MCA was to become LOW resistance vessel

- —mean baby is diverting blood flow to its head to preserve the vital functions at the EXPENSE of non-vital organs

40
Q

Timing for a smooth pregnancy= 37 weeks.

What are indications for earlier delivery?

A
  • growth becomes static (IOL appropriate)
  • abnormal umbilical artery doppler
  • normal umbilical artery doppler with abnormal MCA between 32 and 37 weeks
  • abnormal umbilical artery doppler with abnormal ductus venosus doppler between 24-32 weeks
41
Q

Babies under which particular centile are at a higher risk?

A
  • those below the 3rd centile

- —–babies between 3rd and 10th are more likely to be constitutionally small

42
Q

What advise is given from our College about the delivery of SGA babies?

A

—should be delivered at around 37 weeks REGARDLESS of growth trajectory

43
Q

What is the usual resistance of the umbilical artery?

A

should be LOW
—-when compromised it is HIGH; flow becomes absent and reversed in diastole

—-> MCA decr. resistance to maintain fetal blood flow to the brain

44
Q

What is an indicator of the baby becoming acidotic?

A

—>when ductus venous doppler becomes pulsatile and INCREASES in resistance

45
Q

What does the ductus venous do?

A
  • resp. for shunting oxygenated blood from the placenta AWAY from the liver to the IVC—> Brain