L13: Fetal Growth Flashcards Preview

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Flashcards in L13: Fetal Growth Deck (35):
1

What are the phases of foetal development?

Cellular hyperplasia - 4-20 wks (increase in foetal protein, weight + DNA)
Hyperplasia + concomitant hypertrophy (20-28 wks) - less increase in DNA
Hypertrophy - 28 wks - term, only increase in protein + weight

2

What is the ponderal index?

Baby BMI

3

What is the MAC/HC ratio?

Mid arm circum/head circum ration

4

How many births does foetal growth restriction affect? (Both IUGR & SGA)

3-10%

5

Consequences of foetal growth restriction

More likely to die in first yr of life + suffer from neonatal problems

6

Basis of foetal programming

Plastic neuroendocrine system that can adapt to different nutrient states that continues throughout life

7

What can foetal programming increase risk of?

Obesity, type 2 diabetes, BP, stroke, HF
Mostly secondary to changes in growth, metabolism + vasculature

8

Mother born SGA are more likely to?

Have SGA babies w higher perinatal mortality

9

Definite of perinatal mortality

Dying from 24 wks of pregnancy to 28 days of life

10

What are the mechanisms of train generational effects of foetal programming

Epigenetics & inheritance of maternal mitochondria
Food restriction alters number + function of mitochondria

11

What is macrosomia?

Birth weight > 4500g - clinical opposite to IUGR

12

Causes of macrosomia

Greater gestational age, Male, maternal obesity, multiparity, maternal diabetes pre existing, erythroblastosis fetalis

13

What is erythroblastosis fetalis?

Foetal has HF —> fluid build up causing macrosomia

14

Pathophysiology of macrosomia

Increased maternal glucose —> increased foetal insulin —> increased IGF

15

What regulates foetal growth?

Combination of substrate availability + endocrine/paracrine signalling (mainly IGF-1 + 2)

16

What are the maternal factors affecting growth?

Ethnicity, BM1, Drugs esp cigarettes, alcohol, nutrition, maternal hypoxia, anaemia, chronic disease

17

Why is maternal nutrition not that significant unless extreme under nutrition/placental insufficiency?

Placenta acts as moderator so any takes what it need from mother

18

When in gestation does growth restriction occur?

Late gestation

19

What are the foetal factors affecting growth?

Genetic factors e.g. Edwards, Patau’s, downs
Growth factors e.g. IGF, thyroxine
Congenital infection e.g. cytomegalovirus, toxoplasmosis, rubella

20

What are the placental factors affecting growth?

Primary - errors in placentation+ EVT invasion in 1st trimester, often autoimmune
Secondary - hypertension, CKD, vasculitis, pro thrombotic disease, also due to twins sharing placenta

21

How with IUGR change Doppler flow?

Diastolic notching - low flow in umbilical arteries during diastole
Raised RI

22

What is the most common factor affecting foetal growth?

Placental factors

23

What is symmetrical IUGR?

Overall small baby due to early growth insult e.g. virus, chromosomal abnormality
Disruption in cell hyperplasia stage if growth (4-20wks)

24

When is doppler ultrasound done?

~ 6 + 20wks but only for high risk women

25

What is asymmetrical IUGR?

Preserved growth of head as prioritising brain development
Decreased glycogen stores also decrease abdo circumference

26

What can be used to assess fetal growth?

Symphsio fundal height
Ultrasound (look at head + abdo circumference)

27

When is ultrasound scanning done in pregnancy?

12 wk - confirm due date, ch3ck developmental/genetic issues?
18-22 wks - know sex of baby + check for abnormalities

28

What can be used to check foetal wellbeing short & long term?

Short - cardiotocograph (monitor fetal HR using transducer + uterine contractions), baby must be delivered immediately if there’s problem
Long- Doppler ultrasound, if there’s a problem, MCA + ductus venous can also be checked if flow is affecting brain/heart

29

What may growth restriction —> lower amniotic volume?

Blood diverted away from kidneys to brain so lower urine vol

30

Why does gestational diabetes occur?

Pregnancy is a state of insulin resistance due to hormonal, inflammatory changes (e,g. Release of placenta growth hormone)
Resistance increase with higher gestation

31

What is the high risk group screened for GD?

Previous GD, history of insulin resistance, family history, PCOs, raised BMI, previous big baby, south Asian/black,
Screen immediately if: significant glycosuria, macrosomia, polyhydaminos

32

What are the maternal complications of gestational diabetes?

Pre eclampsia, pre term labour, instrumental delivery/c section, diabetes continues

33

What are the foetal consequences of gestational diabetes?

Macrosomia —> shoulder dystocia
Polyhydaminos
Perinatal mortality due to hypoglycaemia after birth, jaundice, polycythaemia, hypocalcaemia

34

Post natal management for gestational diabetes?

Slowly waning off insulin better
Encourage breastfeeding
Fasting glucose test done in 6 wks time/ HbA1C 3 months later to check if there’s still diabetes

35

Management of GD during Pregnancy?

Diet restriction, metformin, insulin last - regular finger prick tests w strict glucose control, ultrasound done every 3-4 wks, foetal heart beat