Foetal growth problems Flashcards
Measurements to diagnose:
- Oligohydramnios
- Polyhydramnios
AFI < 5cm, or
AFI < 5th percentile, or
AFV < 500 ml at 32-36 weeks
Single deepest pocket < 2cm
AFI > 24 cm
SDP > 8 cm
Phenytoin terategenicity
IUGR, hypoplastic nails, dysmoprhic features, small head
Jane is a 35 year old lady in her third pregnancy. She has been referred into the hospital antenatal clinic at 32 weeks by her Community midwife. She is concerned the baby may have fetal growth restriction. Previously this has been an uncomplicated midwifery led pregnancy, she has no medical problems.
a) How would her midwife have come to the diagnosis of suspected fetal growth
restriction?
b) What additional information would you like about the current pregnancy?
c) What information would you like about her past pregnancies?
d) What clinical examination would you like to undertake?
e) What investigation(s) would you like to perform?
a) Symphisio-fundal height (SFH) - below 10th percentile
b) - Maternal risk factors: drug/smoking/alcohol, teratogens, pre-pregnancy BMI, pre-eclampsia, chronic diseases, maternal infections
- Foetal abnormalities, multiple gestation
c) Previous SGA, parity, etc.
d) SFH? / foetal heart doppler?
e) - Abdominal USS
- Umbilical artery Doppler
An USS shows the HC, AC and FL to be on the 50th centile, AFI is 132 and Umbilical Artery Doppler shows positive EDF. The Estimated fetal weight is below the 10th centile.
a) How can you explain these results?
b) What is the underlying diagnosis?
c) What would be your further management for the pregnancy?
a) Asymmetrical IUGR
b) Placental insuffiiency: likely pre-eclampsia
c) - Labetalol if BP > 150/100
- Obstetrician led care
- Manage until 34 weeks if possible without delivery
- Then consider delivery
- If delivery likely before 36 weeks, give CS
Define:
a) Small for dates/ SGA
b) IUGR
c) Low birth weight
d) Macrosomia
e) Large for dates/ LGA
a) Below 10th percentile for birth weight:
- May just be constitutionally small
b) Slowing or ceasing of growth in utero:
- Born with features of malnutrition (usually SGA also, but may be normal weight)
c) Birth weight < 2.5 kg
d) Birth weight > 4 kg
e) Birth weight > 90th percentile for birth weight
IUGR: causes
a) Maternal - obstetric and non-obstetric
b) Foetal
c) Placental
Maternal factors.
- Maternal age (< 16 or > 35).
- Low socio-economic status.
- Nulliparity or grandmultiparity (> 5)
- Previous delivery of an SGA newborn.
- Substance abuse (smoking, alcohol, marijuana, cocaine)
- Medication (eg, warfarin, steroids, folate inhibitors)
- Maternal pre-pregnancy BMI < 20 or obese
- TORCH infection
- Chronic diseases (eg. asthma, cyanotic congenital heart disease, CKD, SLE/APLS, Sickle cell)
Fetal factors.
- Chromosomal abnormalities - eg, trisomies 13, 18, or 21,
- Genetic syndromes - eg, Russell-Silver syndrome, Fanconi’s syndrome.
- Major congenital anomalies - eg, tracheo-oesophageal fistula, congenital heart disease, NTDs, congenital diaphragmatic hernia,
- Twins
- Metabolic disorders, eg. PKU
Placental factors.
- Pre-eclampsia
- Placental abruption.
IUGR: classification (For each, give: - the physiology, - some causes, - the antenatal and postnatal appearance - prognosis)
Symmetrical IUGR.
- Cause of IUGR earlier in pregnancy.
- Examples:
- Antenatal: head + abdo circumference, and fetal length all proportionally reduced.
- Postnatal: weight, length + head circumference all reduced.; features of malnutrition less pronounced
- Prognosis: poor.
Asymmetrical IUGR.
- Cause of IUGR later in pregnancy.
- Examples:
- Antenatal: abdominal circumference decreased; head circumference and femur length all normal.
- Postnatal: reduction in weight; length and head circumference normal (brain-sparing growth); features of malnutrition more pronounced
- Prognosis: relatively good.
Mixed IUGR.
- Cause: results when early IUGR is affected further by placental causes in late pregnancy.
- Affected neonates have clinical features of both symmetrical and asymmetrical IUGR at birth
Complications of IUGR/SGA babies.
a) Short-term (neonatal) - pulmonary, metabolic, GI
b) Childhood
c) Adulthood
a) - Pulmonary: asphyxia, meconium aspiration, persistent pulmonary hypertension, pulmonary haemorrhage
- Metabolic: sepsis, hypothermia, hypoglycaemia, hyperglycaemia, hypocalcaemia, polycythaemia, jaundice
- GI: feeding difficulties, feed intolerance, NEC
b) Neurodevelopmental:
- cerebral palsy, ADHD, behavioural issues, cognitive issues
c) Obesity, HTN, CVD, diabetes
Prevention of SGA.
Aspirin in women AT-RISK of pre-eclampsia at or before 16 weeks gestation
Oligohydramnios: causes
Physiological basis: inadequate foetal urine production or ROM
Foetal.
- Chromosomal
- Genetic
- Renal - obstructive uropathy, kidney agenesis
- IUGR
- PROM
- Foetal death
Maternal.
- Pre-eclampsia
- Diabetes
- HTN
- ACE inhibitors
Oligohydramnios: management
- Assess foetal growth
- Delivery at term or before if worried about growth
- Amnioinfusion
Polyhydramnios: causes
Idiopathic (50%)
Inadequate foetal swallowing - oesophageal atresia, NTD, trisomy, neurological disorder (microcephaly)
Polyuria - GDM
Multiple pregnancy
Hydrops foetalis
Polyhydramnios: management
- Assess foetal growth
- Treat any underlying causes (eg. tight glycaemic control in GDM)
- Amnioreduction/ indomethacin
- Delivery if foetal distress
- CS if delivery likely < 36 weeks
Jane is a 21 year old lady in her first pregnancy. She has been referred into the hospital antenatal clinic at 28 weeks by her Community midwife. She is concerned the baby may be large for dates. Previously this has been an uncomplicated midwifery led pregnancy. She has no medical problems.
a) How would her midwife have come to the diagnosis of suspected large for dates?
b) What additional information would you like about the current pregnancy?
c) What clinical examination would you like to undertake?
d) What investigation(s) would you like to perform?
a) SFH > 90th percentile
b) - Maternal RFs: HTN, diabetes, drugs, infection (TORCH)
- Foetal RFs: twins, abnormality
c) SFH? / foetal heart doppler?
d) Abdominal USS
- Umbilical artery doppler
An USS shows the HC and the FL to be on the 50th centile and the AC to be above the 95th centile, AFI is 260. The Estimated fetal weight is above the 90th centile.
a) How can you explain these results?
b) What is the underlying diagnosis?
c) What would be your further management for the pregnancy?
a) Asymmetrically LGA (overweight)
b) GDM
c) - Glycaemic control: INSULIN (as already has complications = macrosomia)
- Monitor foetal growth
- CS if risk of preterm birth
- Do not let them carry past 40 +6 (offer IOL before)
- Let them know risk of PV delivery
