fetal growth restriction -ILA Flashcards
(34 cards)
Define small for dates
estimated weight less than that in the tenth centile
Define large for dates
estimated weight in top ten percentile
Define fetal growth restriction
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.
What is the difference between asymmetric and symmetric growth restriction?
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
Define low birth weight
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
Define macrosomia
A baby diagnosed with fetal macrosomia has a birth weight of more 4,000 grams, regardless of his or her gestational age.
What are the risk factors for FGR?
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
What infections do we screen for in maternity?
TRCH- toxoplasmas, rubella, CMV, herpes
What are the trisomnies 13, 18 and 21?
pauteaus, edwards, downs
What are the two main risk factors for macrosomia?
obesity and diabetes mellitus
What is the management of FGR?
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
How is FGR and macrosomia diagnosed?
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.
How would you investigate FGR?
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
What is FGR a risk factor for for future child?
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)
What can macrosomia cause?
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
What is Pederson’s hypothesis?
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
Name risk factors for macrosomia
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)
How does the fetus adapt to the hypoxemia cause by reduced placental function?
- Erythropoietin release causes RBC production and eventually polycythemia.
- hypoglycaemia
- reduced thyroid function
- blood is redirected to the head, myocardium and adrenal glands
How can you try to prevent FGR and macrosomia?
Edit modifiable risk factors in mother eg drug use, smoking, weight loss/gain, diabetic control
What are the HC, AC, FL and AFI?
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
What is EDF on an umbiblical artery doppler?
EDF=end diastolic flow – positive is normal and not reversed- so placenta is functioning normally, negative may indicate placenta blood flow is not working
What is polyhydramnios?
Excessive amniotic fluid (polyhydramnios)- commonly caused by macrosomia as amniotic fluid reflects urine output and baby with higher blood sugar will urinate more
How would you screen for gestational diabetes?
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
What are the complications of polyhydramnios?
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)
