Maternal allopurinol administration during suspected fetal hypoxia: a novel neuroprotective intervention? A multicentre randomised placebo controlled trial.

OBJECTIVE: To determine whether maternal allopurinol treatment during suspected fetal hypoxia would reduce the release of biomarkers associated with neonatal brain damage. DESIGN: A randomised double-blind placebo controlled multicentre trial. PATIENTS: We studied women in labour at term with clinical indices of fetal hypoxia, prompting immediate delivery. SETTING: Delivery rooms of 11 Dutch hospitals. INTERVENTION: When immediate delivery was foreseen based on suspected fetal hypoxia, women were allocated to receive allopurinol 500 mg intravenous (ALLO) or placebo intravenous (CONT). MAIN OUTCOME MEASURES: Primary endpoint was the difference in cord S100ß, a tissue-specific biomarker for brain damage. RESULTS: 222 women were randomised to receive allopurinol (ALLO, n=111) or placebo (CONT, n=111). Cord S100ß was not significantly different between the two groups: 44.5 pg/mL (IQR 20.2-71.4) in the ALLO group versus 54.9 pg/mL (IQR 26.8-94.7) in the CONT group (difference in median -7.69 (95% CI -24.9 to 9.52)). Post hoc subgroup analysis showed a potential treatment effect of allopurinol on the proportion of infants with a cord S100ß value above the 75th percentile in girls (ALLO n=5 (12%) vs CONT n=10 (31%); risk ratio (RR) 0.37 (95% CI 0.14 to 0.99)) but not in boys (ALLO n=18 (32%) vs CONT n=15 (25%); RR 1.4 (95% CI 0.84 to 2.3)). Also, cord neuroketal levels were significantly lower in girls treated with allopurinol as compared with placebo treated girls: 18.0 pg/mL (95% CI 12.1 to 26.9) in the ALLO group versus 32.2 pg/mL (95% CI 22.7 to 45.7) in the CONT group (geometric mean difference -16.4 (95% CI -24.6 to -1.64)). CONCLUSIONS: Maternal treatment with allopurinol during fetal hypoxia did not significantly lower neuronal damage markers in cord blood. Post hoc analysis revealed a potential beneficial treatment effect in girls. TRIAL REGISTRATION NUMBER: NCT00189007, Dutch Trial Register NTR1383.

Antenatal allopurinol for reduction of birth asphyxia induced brain damage (ALLO-Trial); a randomized double blind placebo controlled multicenter study.

BACKGROUND: Hypoxic-ischaemic encephalopathy is associated with development of cerebral palsy and cognitive disability later in life and is therefore one of the fundamental problems in perinatal medicine. The xanthine-oxidase inhibitor allopurinol reduces the formation of free radicals, thereby limiting the amount of hypoxia-reperfusion damage. In case of suspected intra-uterine hypoxia, both animal and human studies suggest that maternal administration of allopurinol immediately prior to delivery reduces hypoxic-ischaemic encephalopathy. METHODS/DESIGN: The proposed trial is a randomized double blind placebo controlled multicenter study in pregnant women at term in whom the foetus is suspected of intra-uterine hypoxia.Allopurinol 500 mg IV or placebo will be administered antenatally to the pregnant woman when foetal hypoxia is suspected. Foetal distress is being diagnosed by the clinician as an abnormal or non-reassuring foetal heart rate trace, preferably accompanied by either significant ST-wave abnormalities (as detected by the STAN-monitor) or an abnormal foetal blood scalp sampling (pH < 7.20).Primary outcome measures are the amount of S100B (a marker for brain tissue damage) and the severity of oxidative stress (measured by isoprostane, neuroprostane, non protein bound iron and hypoxanthine), both measured in umbilical cord blood. Secondary outcome measures are neonatal mortality, serious composite neonatal morbidity and long-term neurological outcome. Furthermore pharmacokinetics and pharmacodynamics will be investigated.We expect an inclusion of 220 patients (110 per group) to be feasible in an inclusion period of two years. Given a suspected mean value of S100B of 1.05 ug/L (SD 0.37 ug/L) in the placebo group this trial has a power of 90% (alpha 0.05) to detect a mean value of S100B of 0.89 ug/L (SD 0.37 ug/L) in the 'allopurinol-treated' group (z-test2-sided). Analysis will be by intention to treat and it allows for one interim analysis. DISCUSSION: In this trial we aim to answer the question whether antenatal allopurinol administration reduces hypoxic-ischaemic encephalopathy in neonates exposed to foetal hypoxia. TRIAL REGISTRATION NUMBER: Clinical Trials, protocol registration system: NCT00189007.