Abnormal Fetal Growth: Aetiology and Management PDF

Summary of ABNORMAL FETAL GROWTH: AETIOLOGY AND MANAGEMENT (Dr Izuka Emmanuel Obiora) Outline: o Determinants of birth weight o IUGR o Macrosomia Determinants of Birth Weight o Gestational age o Maternal size o Fetal gender o Parity o Ethnicity IUGR Introducti...

Summary of ABNORMAL FETAL GROWTH: AETIOLOGY AND MANAGEMENT (Dr Izuka Emmanuel Obiora) Outline: o Determinants of birth weight o IUGR o Macrosomia Determinants of Birth Weight o Gestational age o Maternal size o Fetal gender o Parity o Ethnicity IUGR Introduction: o Defined as a fetus whose:  Estimated weight < 10th percentile for gestational age  Or abdominal circumference < 2.5th percentile Causes: o Fetal:  Genetic  Chromosomal  Congenital malformation  Multiple pregnancy o Placental:  Ischemic placental diseases (ex. placental abruption)  Multiple infarcts  Abnormal cord insertion  Circumvallate placenta   Chorioangioma o Maternal:  Reduced utero-placental flow:  Pre-eclampsia, eclampsia  Renal disease, hypertension, diabetes  Hypoxemia:  Severe anemia, chronic lung disease  Cyanotic heart disease, high altitude  Malnutrition  Substance abuse  Drugs:  Warfarin, anticonvulsants  Beta-blockers, chemotherapy  Infections:  TORCH (esp. CMV)  Others:  Vit D deficiency, ART conception  Radiotherapy, uterine malformation etc. Management: o Screening:  Fetal size estimation by palpation  Symphiso-fundal height (SFH) measurement o Investigations:  Diagnosis is via USS:  Measures fetal biometry, amniotic fluid index (AFI)  Doppler studies of umbilical arteries, cardiotocography (CTG)  Screens for fetal anomalies  Fetal karyotyping  FBC, SEUCr, LFT, urate levels  Antiphospholipid antibodies, TORCH viral studies  Chromosomal studies o Antenatal care:  USS should be done every 2 weeks to measure AFI and do Doppler studies  Estimated fetal weight should be measured every 2 weeks  CTG should be done daily  Give mother steroids   Pregnancy should not exceed 37 weeks GA o Delivery:  Depends on severity of IUGR  If GA is close to term and the fetus is not compromised, induce labor  If there are signs of fetal distress, elective CS is indicated Complications: o Short term:  Hypoglycemia, hypothermia  Hyperviscosity syndrome, birth asphyxia  Impaired immunity, respiratory distress syndrome (RDS)  Necrotizing enterocolitis (NEC) o Long term:  Cerebral palsy, IQ falls  Increased risk of HTN, ischemic heart diseases, hypercholesterolemia etc. in adulthood Prevention: o Stop smoking o Avoid drugs and alcohol o Minimize risk of multiple pregnancy, infections o Treat thrombophilias, treat vit D deficiency o Pre-conception counselling Not effective in prevention: o Bed rest, long-chain fatty acids o Antihypertensives, beta-agonists Macrosomia Introduction: o Birth weight > 4kg Causes: o Constitutional  o Genetic disorders:  Beckwith-Wiedemann syndrome, Sotos syndrome  Weaver syndrome, Berardinelli lipodystrophy o Gestational DM o Hyper-insulinemia in non-diabetics Risk factors: o High BMI, excessive weight gain in pregnancy o Multiparity, advanced maternal age o DM, male infant, post-term pregnancy o Previous macrosomic infant, mother was macrosomic at birth Management: o Screening:  Fetal size estimation by palpation  SFH measurement o Diagnosis:  Fetal biometry (biparietal diameter, head circumference, abdominal circumference and femur length)  Use it to calculate estimated fetal weight  The only downside is that USS (which is used for fetal biometry) is less accurate for large babies o Differentials:  Polyhydramnios, multiple pregnancy  Uterine fibroids, pelvic masses  Maternal obesity o Delivery:  CS Complications: o Short term:  Fetal:  Birth trauma, Erb’s palsy  Birth asphyxia, neonatal hypoglycemia  Polycythemia, neonatal jaundice  Respiratory distress syndrome  Maternal:   Genital tract trauma, postpartum hemorrhage  Increased risk of emergency CS o Long term:  Neurodevelopmental delay  Decreased head circumference at 3 years  Increased risk of type 2 DM  Obesity Prevention: o Normalize BMI before conception o Early detection and good control of gestational DM o Moderate exercise during pregnancy