fetal growth restriction -ILA

Question 1

Define small for dates

Answer 1

estimated weight less than that in the tenth centile

Question 2

Define large for dates

Answer 2

estimated weight in top ten percentile

Question 3

Define fetal growth restriction

Answer 3

Intrauterine growth restriction is a condition where a baby’s growth slows or ceases when it is in the uterus – baby fails to achieve its growth potential and doesn’t maintain growth velocity on growth chart.

Question 4

What is the difference between asymmetric and symmetric growth restriction?

Answer 4

Symmetric–> HC and AC equally affected eg congenital problem

Asymmetric–> HC>AC –> if blood supply restricted then blood is diverted to to head rather than abdomen

Question 5

Define low birth weight

Answer 5

Low birth weight is defined by the World Health Organization as a birth weight of a infant of 2,500 g or less, regardless of gestational age

Question 6

Define macrosomia

Answer 6

A baby diagnosed with fetal macrosomia has a birth weight of more 4,000 grams, regardless of his or her gestational age.

Question 7

What are the risk factors for FGR?

Answer 7

Placental factors: abnormal trophoblast invasion eg pre-eclampsia, praevia, accreta, infarction, abruption.

Genetic abnormalities: trisomnies 13, 18 and 21, Turners, triploidy

Congenital: tetralogy of Fallot, Infections

Risk factors: multiple pregnancy, smoker, drug use eg cocaine and heroin, previous SGA baby, Fhx, antiphospholipid syndrome, APH, anaemia, malnutrition, mother having chronic disease eg DM, htn, CKD, VTE, geriatric mother

Question 8

What infections do we screen for in maternity?

Answer 8

TRCH- toxoplasmas, rubella, CMV, herpes

Question 9

What are the trisomnies 13, 18 and 21?

Answer 9

pauteaus, edwards, downs

Question 10

What are the two main risk factors for macrosomia?

Answer 10

obesity and diabetes mellitus

Question 11

What is the management of FGR?

Answer 11

Aim is to keep fetus in as long as possible but before it becomes compromised

• monitor with U/S, kickcoubt and growth chart.
• If dopplers remain normal aim for induction of labour at 37 weeks
• If absent or reversed end-diastolic flow in umbilical artery doppler then consider LSCS
• Corticosteroids for lung development eg betamethasone
• Skin to skin contact as may have temp, regulation problems
• Feed in two hours of birth as more likely to be hypo

Question 12

How is FGR and macrosomia diagnosed?

Answer 12

If SFH on growth chart which plots the symphysis fundal height (which is customised for age, parity, BMI, ethnicity and birthweights of previous children) estimates that their child with have SFG/LFG then they are at high risk.

Question 13

How would you investigate FGR?

Answer 13

Ultrasound measurement of fetal size – look for AC, FL, HC
Fetal kick count
CTG
Rule out anaemia, blood pressure problems and diabetes
Women in whom measurement of SFH is inaccurate (for example, BMI >35, large fibroids, hydramnios) should be referred for serial assessment of fetal size, using ultrasound.
Umbilical artery doppler (if normal repeat every 14 days)
Interpret amniotic fluid
Test for infections

Question 14

What is FGR a risk factor for for future child?

Answer 14

Chance of stillbirth, emergency c-section and perinatal mortality is higher
Higher risk of chrinic diseases eg htn, cognitive impairment, thyroid disease in adulthood
Cerebral palsy!!!, meconium aspiration, persistent pulmonary hypertension, hypothermia, hypoglycaemia,( less fat deposition) hypocalcaemia, polycythaemia, jaundice, feeding difficulties, feed intolerance, necrotising enterocolitis (caused by less blood flow to the colon)

Question 15

What can macrosomia cause?

Answer 15

Risk of birth injury eg shoulder dystocia (can lead to brachial plexus injury)-
Increased risk of genital tract laceration
Increased risk of PPH
Increased risk of uterine rupture (had prior C-section or major uterine surgery, fetal macrosomia increases the risk of uterine rupture — uterus tears open along the scar line from the C-section or other uterine surgery. An emergency C-section is needed to prevent life-threatening complications.)
Polycythaemia (leading to jaundice)
Respiratory distress syndrome (due to high insulin)
Metabolic syndromes
Hypoglycaemia prone and hypocalcaemia
Left colon syndrome- mimics Hirschsprung’s, temporary bowel obstruction

Question 16

What is Pederson’s hypothesis?

Answer 16

Macrosomia babies (due to maternal DM) are more at risk of shoulder dystocia as a mother with DM causes increase in insulin in baby which then causes increased fat growth especially around shoulders

Question 17

Name risk factors for macrosomia

Answer 17

obesity, DM, Gestational age over 35; pregnancies that go beyond 40 weeks, previous hx of it, parity

Congenital anomalies (transposition of great vessels) – Hydrops fetalis (Hydrops fetalis is a condition in the fetus characterized by an accumulation of fluid, or oedema, in at least two fetal compartments.)

Use of some antibiotics (amoxicillin, pivampicillin) during pregnancy –> Hydrops fetalis

Genetic disorders of overgrowth (e.g. Beckwith–Wiedemann syndrome, Sotos syndrome)

Question 18

How does the fetus adapt to the hypoxemia cause by reduced placental function?

Answer 18

• Erythropoietin release causes RBC production and eventually polycythemia.
• hypoglycaemia
• reduced thyroid function
• blood is redirected to the head, myocardium and adrenal glands

Question 19

How can you try to prevent FGR and macrosomia?

Answer 19

Edit modifiable risk factors in mother eg drug use, smoking, weight loss/gain, diabetic control

Question 20

What are the HC, AC, FL and AFI?

Answer 20

These are measurements on the U/S
HC= fetal head circumference  
FL=femur length 
AC= abdominal circumference 
AFI= amniotic fluid index - An AFI between 8-18 is considered normal

Question 21

What is EDF on an umbiblical artery doppler?

Answer 21

EDF=end diastolic flow – positive is normal and not reversed- so placenta is functioning normally, negative may indicate placenta blood flow is not working

Question 22

What is polyhydramnios?

Answer 22

Excessive amniotic fluid (polyhydramnios)- commonly caused by macrosomia as amniotic fluid reflects urine output and baby with higher blood sugar will urinate more

Question 23

How would you screen for gestational diabetes?

Answer 23

Gestational Diabetes ask about Fhx, BMI more than 30, ethnicity ———> can’t use normal symptoms of diabetes for pregnancy as some of this are normal for pregnancy eg polydipsia
Glucose tolerance test
Ultrasound
Urine dip for glucose in urine

Question 24

What are the complications of polyhydramnios?

Answer 24

Polyhydramnios’s is a risk for PPH, preterm labour due to uterine atony, more chance of breech, more risk of cord prolapse (emergency where water goes and placenta emerges before baby’s head- so blood vessels constrict and baby becomes distressed)

Question 25

At what values do you diagnose gestational diabetes for the OGTT?

Answer 25

REMEMBER 5,6,7,8

Fasting-5.6
Random-7.8

Question 26

What is the management for gestational diabetes?

Answer 26

Manage with diet and exercise if possible, if not use metformin
If manage with the above then induce at full term
If control with insulin need to induce at 37-38 weeks
Recommend c-section

Question 27

What is the definition of oligohydramnios?

Answer 27

amniotic fluid <5th centile , usually due to decreased fetal urination

Question 28

aside from gestational diabetes what else may cause polyhydramnios?

Answer 28

less swallowing (eg oesopehageal fistula, duodenal atresia), idiopathic, cardiovascular defect, microcephaly,
neural tube defect, multiple pregnancy, foetal anaemia, congenital infection eg rubella or parvovirus, hydrops fetalis (excess fluid in one or more fetal compartments
e.g. pleura, abdo space), drug use, maternal hypercalcaemia

Question 29

What is potter sequence during oligohydroamnios?

Answer 29

Pulmonary hypoplasia (3rd- with normal amniotic fluid the fetus swallows fluid which expands lung - without this lungs fail to fully expand)
Oligohydroamnios (2nd)
Twisted face
Twisted skin
Extremity deformities (twisting and deformities is due to less fluid -> less cushioning -> injury to fetus)
Renal agenesis (1st) can’t urinate

Question 30

Name some causes of oligohydroamnios

Answer 30

Rupture of amniotic membrane, cystic dysplasia, ureteral atresia, chonic hypoxia, anuria or oliguria, post-term pregnancy but unknown why, foetal demise, placenta abruption, twin to twin transfusion syndrome, maternal dehydration, uteroplacenta insufficient, HTN, pre-eclampsia, diabetes, ace-I

Question 31

How is oligohydroamnios managed?

Answer 31

before term - expectant management watch and wait depending on health status, continuous HR monitor in labour, at term- deliver,
after term - caesarean delivery.
Treat cause and maternal dehydration.
Amnioinfusion (sodium chloride infused through uterine
wall

Question 32

What may be sx of polyhydroamnios?

Answer 32

uterus large for date (seen clinical or USS)
SOB, dyspepsia, constipation, swollen ankles, premature labour or PROM, cord prolapse, abnormal foetal presentation, if sudden enlargement of abdo (acute
polyhydramnios) most common in twins (results in unequal distribution of blood from twin
to twin

Question 33

what does polyhydroamnios increase risk of?

Answer 33

Risk of premature birth, premature rupture of membranes, cord prolapse, postpartum haemorrhage, foetal health condition

Question 34

How is polyhydroamnios mx?

Answer 34

extra USS and monitoring
give steroid if premature
prostaglandin synthestase inhibitors (indoemtacin) reduces renal blood flow and reduce foetal urination - a type of NSAID
Amnioreduction – drainage of amniotic fluid under USS – may be indicated
Induction of labour if foetal distress develops