Dr Stephanie Smith1, Professor Catherine Williamson1, Dr Charlotte Frise1, Ms Mandish Dhanjal1
1Imperial College Healthcare NHS Trust, London, United Kingdom
Biography:
Stephanie Smith is an Obstetrics and Gynaecology trainee in Kent, Surrey and Sussex, United Kingdom. She is currently completing a Clinical Fellowship in Obstetrics and Obstetric Medicine at Queen Charlotte’s and Chelsea Hospital, Imperial College Healthcare NHS Trust.
Abstract:
Introduction: High levels of unconjugated bilirubin in pregnancy cross the placental barrier leading to high levels in the neonate increasing the risk of developmental delay, kernicterus and fetal demise; serum concentrations ≤170 umol/L are thought to be safe in pregnancy.
Case: A 41-year-old woman presented in her 9th pregnancy, with a history of congenital unconjugated hyperbilirubinaemia, presumed to be secondary G6PD deficiency. All her children required treatment for neonatal jaundice; three have developmental delay of varying severity. Next generation sequencing for cholestasis-associated genetic abnormalities was performed; heterozygosity for variants of uncertain significance in UGT1A1, ABCB4 and PEX1 were identified.
At 22 weeks the unconjugated bilirubin concentration was 258 umol/L (other investigations were normal). She commenced phenobarbitone a week later; resulting initially in an improvement, with levels plateauing at 211 umol/L. At 30 weeks’ gestation rifampicin 150mg twice daily was introduced for additional enzyme induction and to enhance bilirubin excretion; unconjugated bilirubin concentrations fell to <170umol/L. Fetal growth scans were normal throughout pregnancy, and she was normoglycaemic.
At 35 weeks, serum unconjugated bilirubin concentrations rose to >200 umol/L. Following a multidisciplinary discussion it was decided that the risks of preterm delivery were lower than the risks of the fetal exposure to the high levels of unconjugated bilirubin and induction of labour was planned.
Following uncomplicated vaginal birth the baby was admitted to the neonatal unit for intensive phototherapy and IVIg. Neonatal bloods were negative for G6PD deficiency, and showed a bilirubin level of 169 umol/L, that rapidly decreased to 43 umol/L over 48 hours. The baby was then discharged home.
This case illustrates the potential of phenobarbitone with rifampicin to reduce serum unconjugated bilirubin to concentrations below the threshold associated with risks to fetal brain development.
Keywords
Unconjugated hyperbilirubinaemia
Phenobarbitone
References
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