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Flashcards in Small for Dates/Pre-term birth Deck (25):
1

What is a pre-term birth?

Delivery between 24 and 36+6 weeks

2

What are the survival rates of pre-term births?

24 weeks approx 20-30%
27 weeks 80%
32 weeks >95%

3

What is the prevalence of pre-term births?

6-7%

4

What are the possible causes of a pre-term birth?

Infection
Over distension: multiple, polyhydramnios
Vascular: placental abruption
Intercurrent illness: pyelonephritis/UTI, appendicitis, pneumonia
Cervical incompetence
Idiopathic

5

What are some of the RFs/associations of pre-term birth?

Previous PTL (20% x1, 40% x2)
Multiple (50% risk)
Uterine anomalies
Age (teenagers)
Parity (=0 or >5)
Ethnicity
Poor socio-economic status
Smoking
Drugs (esp cocaine)
Low BMI (<20)

6

Why do pre-term births occur?

25% planned C section: severe pre-eclampsia, kidney disease or poor fetal development
20% premature rupture of membranes
25% emergency event: placental abruption, infection, eclampsia
40% unknown

7

What is small for gestational age (SGA)?

Infant with a birthweight that is less than 10th centile for gestation corrected for maternal height, weight, fetal sex and birth order

8

What maternal factors can cause poor growth in IUGR?

Lifestyle: smoking, alcohol, drugs
Height and weight
Age
Maternal disease e.g. HT

9

If a baby is under the 10th centile, what categories can it be described under?

SGA
Intra-uterine growth restriction (IUGR)

10

What fetal factors can cause poor growth in IUGR?

Infection e.g. rubella, CMV, toxoplasma
Congenital anomalies e.g. absent kidneys
Chromosomal abnormalities e.g. Down’s syndrome

11

What placental factors can cause poor growth in IUGR?

Infarcts
Abruption
Often 2' to HT

12

How can IUGR be classified?

Symmetrical
Asymmetrical

13

What are antenatal/in labour consequences of being growth restricted?

Risk of hypoxia and/or death

14

What are some post natal consequences of being growth restricted?

Hypoglycaemia
Effects of asphyxia
Hypothermia
Polycythaemia
Hyperbilirubinaemia
Abnormal neurodevelopment

15

What clinical features can be seen in poor growth?

Predisposing factors
Fundal height less than expected
Reduced liquor
Reduced fetal movements

16

Overall what is done to assess fetal wellbeing?

Assessment of growth
Cardiotocography
Biophysical assessment
Doppler US

17

What is defined as a loss of baseline variability?

Baseline FHR variability of less than 5bpm

18

What may cause a loss of baseline variability?

Sedative or analgesic drugs used in labour

19

In general the less baseline variability there is means that the possibility of asphyxia is increased or decreased?

Increased

20

What are late decelerations?

Any deceleration whose lowest point is past the peak of the contraction (decelerations with lag time)

21

What does a longer lag time result in?

An increased fetal asphyxia

22

What is included in a biophysical profile?

US assessment
Looks at: movement, tone, fetal breathing movements, liquor volume
Scored out of 10: 8-10 satisfactory, 4-6 repeat, 0-2 deliver

23

What does an umbilical arterial Doppler measure?

Placental resistance to flow

24

What is the risk of delivering too early?

Iatrogenic prematurity

25

What is the risk of delivering too late?

Perinatal asphyxia/IUFD