6.2 - Fetal Growth Restriction - exam

Question 1

Fetal Macrosomia definition

Answer 1

• 4000 - 4500 grams
• causes
  
  • Maternal factors
    
    • history of macrocosmic pregnancy
    • Pregnancy weight gain
    • Parity
    • Glucose intolerance
      
      • gestational diabetes
      • pre gestational diabetes
  • Fetal Factors
    
    • Male
    • beckwith wireman syndrome
  • Significance
    
    • Maternal
      
      • PPH
      • Vaginal Lacerations
      • C-section if EFW is >5000 or >4500 for a gestational diabetes
    • Fetal
      
      • Shoulder Dystocia
      • Clavicular fracture
      • lower Apgar score
      • obesity later in life

Question 2

Diagnosis of macroscomia

Answer 2

• fundal height
• clinical palpation of estimate weight
• U/S - estimated fetal weight is ruling out macrosmia
  *

Question 3

Management of macrosomia

Answer 3

• Induction not required

Question 4

Intra uterine growth restriction

Answer 4

< than 10% centile

Question 5

Significance of IUGR

Answer 5

• Try to identify infants who are:
  
  • short term morbidity and mortality:
    
    • May potentially lack adequate reserve
  • long term morbidity and mortality:
    
    • Predict long term health risks:
      
      • cardiovascular disease
      • insulin resistance
      • obesity
  • smaller the fetus the greater the risk

Question 6

Early onset IUGR V Late IUGR

Answer 6

• Early onset IUGR
  
  • Fetal growth: cellular hyperplasia
  • can lead to irreversible decrease organ size and function
    
    • Maternal factors
      
      • infection (rubella, varicella, CMV
      • Smoking
      • multiple pregnancies
      • chronic maternal disease
• Late onset IUGR
  
  • Fetal growth: cellular hypertrophy
  • more amenable to restoration of fetal size with adequate nutrition
    
    • factors
      
      • uteroplacental insufficiency

Question 7

Diagnosis of IUGR

Answer 7

• Fundal height measurement
• clinical palpation of estimate fetal weight
• estimated fetal weight
• doppler velocity of fetal vessels

Question 8

Uterine Artery systolic diastolic (S/D)

Answer 8

• fetal placental circulation
• placental resistance increases
  
  • diastolic flow decrease
  • there is a increase in the S/D ratio
• Absent/reversed end diastolic flow
  
  • worse perinatal outcomes
  • delivery is necessary
• MCA doppler
  
  • when is there is a decrease in placental perfusion
  • there is an increase of MCA doppler flow

Question 9

Management of IUGR

Answer 9

• Deliver the healthiest possible infant at the optimal time
• fetal surveillance
• timing of delivery
• delivery should occur when the fetal death is greater the neonatal death

Question 10

Normal singleton fetal growth

Answer 10

• is approximately
  
  • 5 grams/ day at 14 -15 weeks of gestation
  • 10 grams/day at 20 weeks of gestation
  • 30 - 35 grams/day at 32 - 34 weeks of gestation
    
    • after 34 weeks gestation the growth rate decreases

Question 11

Definition of normal fetal growth

Answer 11

• expression of the genetic potential growth in a way that is neither constrained nor promoted by internal or external factors

Question 12

Definition of Small for gestational age (SGA)

Answer 12

• Birthweight below the 10th centime of weight for gestation
  
  • this does not necessarily indicate fetal growth restriction
• majority of foetuses with a birthweight below the 10th centime for gestational age are constitutionally small

Question 13

Fetal growth restriction (FGR)

Answer 13

• FGR is defined antenatally by an estimated weight or serial antenatal u/s evidence of growth restriction or growth arrest
• birthweight is below the 10 th percentile

Question 14

Related birthweight definitions

Answer 14

• Low birthweight <2500 grams
• Very low birthweight <1500 grams
• Extremely low birthweight <1000 grams
  
  • Low birthweight can be due to preterm birth, constitutionally small infants or growth restricted infants

Question 15

Common factors associated with low weight for gestation include

Answer 15

• Race
• Maternal size
• Female infant (as opposed to male infant)
• Nulliparity (as opposed to 2nd or 3rd infants)
• History of a baby of low weight for gestation age
• Matrilineal tendency

Question 16

Common Lateral factors associated with fetal growth restriction include

Answer 16

• Multiple pregnancy
• smoking, alcohol, amphetamines, cocaine/crack
• social disadvantage/ DV
• preeclampsia
• previous stillbirth
• Obesity
• Chronic hypertension, especially if associated with atherosclerosis
• connective tissue disorder
• acquired or genetic thrombophilias
• diabetes - especially the white classes indicating diabetic vasculopathy
• cardiac disorders - primary cyanotic cardiac disease
• hypotension < 60mmhg diastolic
• respiratory disease - severe asthma
• anaemia
• renal disease
• Drugs (anticancer agents, narcotics
• poor nutrition

Question 17

Fetal factors

Answer 17

• fetal infection
• malformation
• chromosomal defects

Question 18

Placental factors

Answer 18

• abruption placentae
• placenta praevia
• Thrombosis, infarction (fibrin deposition)
• Choroamnionitis
• Placental cysts - Chorioangioma
• Decreased uteroplacental blood flow

Question 19

Uterine factors

Answer 19

• Fibromyoma (large submucosal fibroids)
• Morpholoigic abnormalities - especially uterine septum

Question 20

Midwifery pregnancy counselling

Answer 20

• Behavioral modifications
  
  • inform women that smoking has been associated with low birthweight, preterm birth and perinatal death
  • Encourage/offer enrolment in smoking cessation programs to reduce/stop smoking

Question 21

Midwives education around nutrition

Answer 21

• severe dietary restriction is related to decreased birthweight
• under-nutrition may be recognised by a low fasting glucose or low maternal weight for height
• low fasting glucose has also been associated in low birthweight in austrlai
• encourage a well balanced diet
• nutritional advice is moderately effective in increasing protein and energy intake of pregnant women

Question 22

Clinical assessments

Answer 22

• Fetal biometry and doppler flow
• Abdo examination
  
  • the predictive value of adobo palp is measuring the SFH as a primary surveillance method for estimating fetal growth in the third trimester is limited
  • SFH measure must betaken form the top of the funds to the fixed point of the upper edge of the pubic symphsis. Measure along the fetal axis using a non-elastic tape measure
  • serial measurement of fundal height and plotting on a growth chart is a useful screening toll and is recommended
• Pregnancy unsuitable for primary surveillance by SFH:
  
  • Fibroids
  • high maternal body mass index
  • high risk pregnancy eg: previous IUGR
• Referral for further investigations if
  
  • the first fundal height measurement is below the 10th centile
  • Consecutive measurements suggest static or slow growth.
• Customised fundal height charts
  
  • routine use of the customised growth chart is still being evaluated
  • Calculation of customised centimes (fundal height and ultrasound growth) requires computer software.
    
    • customised SFH chart is adjusted for sex as well as maternal characteristics such as height, weight, parity and ethnic origin
    • Pathological factors known to affect birth weight and growth such as smoking, hypertension, diabetes and preterm delivery are excluded

Question 23

Clinical assessments continue

Answer 23

• Ultrasound
  
  • routine dating and morphology scans at 18-20 weeks
  • all growth restricted fetuses require careful assessment for malformations
  • serial measurements of abdominal circumference and estimated fetal weight are useful to identify restricted fetal growth
  • serial relationship between the head circumference and abdominal circumference as well as amniotic fluid index are useful indicators for growth pattern
  • fetal structural abnormalities with normal liquor volume and normal uterine or umbilical artery dopplers may also be associated with chromosomal defects

Question 24

https://www.sahealth.sa.gov.au/wps/wcm/connect/156243804ee473e0bed4bfd150ce4f37/Fetal-growth-restricted-WCHN-PPG-22112011.pdf?MOD=AJPERES&CACHEID=ROOTWORKSPACE-156243804ee473e0bed4bfd150ce4f37-lNuWtU8