Presented at the Neonatal Society 2004 Spring Meeting.
Cheong JLY1, Dammann O4, Barthels D4, Simpson J1, Rutherford MA2, Dubowitz L1, Mercuri E1,3, Cowan F1
1 Dept of Paediatrics, Imperial College, Hammersmith Hospital, London, UK
2 Robert Steiner MR Imaging Dept, Imperial College, Hammersmith Hospital, London, UK
3 The Catholic University Hospital, Rome, Italy
4 Perinatal Infectious Disease Epidemiology Unit, Hannover Medical School, Germany
Background : The emphasis on risk factors for focal lesions in the term infant centres on inherited prothrombotic, acquired autoimmune disorders and placental thrombosis. Little attention is placed on antenatal and perinatal events potentially relevant to the aetiology.
Aim: To analyse detailed antenatal and perinatal data from term infants with focal lesions of perinatal onset and to compare these data to that from controls.
Methods : Antenatal and perinatal data (maternal age, race, parity, family history, infertility, maternal illness, pregnancy complcations, rupture of membranes, intrapartum fever, labour length, malpresentation, induction / augementation of labour, analgesia, delivery mode, meconium, Apgar, resuscitation, cord pH, gestational age, sex, birth weight and head circumference) were obtained from obstetric and paediatric notes and parental interview. The same data was extracted for 229 term control infants who had a detailed neonatal neurological exam, cranial US scan and neurodevelopmental assessment at 12-18 months. All case infants had early neonatal MRI scans.
Statistical analysis: chi-square or Fisher’s exact test; t-test or Wilcoxon rank sum test as appropriate. The significance level was set at 0.05.
Results : 88 infants had focal lesions (43 arterial territory infarction, 19 parasagittal infarction, 13 punctate haemorrhage, 16 focal haematoma; 3 infants had two lesions). The majority of infants presented with seizures on days 1-3. Significant risk factors in the case infants were (1) primiparity and family history of seizures or neurological disease, (2) longer gestational age, intrapartum fever, prolonged ROM, OP presentation, instrumental and failed instumental delivery and emergency CS and (3) lower mean birth weight, lower Apgar scores (7 and 9 at 1 & 5 minutes vs 9 & 10 in controls) and cord blood pH (7.17 vs 7.34 in controls). Elective CS and uncomplicated vaginal delivery occurred more commonly in the controls. 15% of the case infants had a prothrombotic factor identified on postnatal investigation.
Conclusions : These data suggest that antenatal factors are uncommon, though not necessarily unimportant, in term infants with focal lesions of perinatal onset. There were many significant differences in labour suggesting that first delivery, abnormal fetal position and difficult instrumental delivery are relevant. There was little evidence for severe asphyxia. Known inflammatory, embolic and thrombotic etiologies are supported by maternal fever and the prothrombic data. These data allow further investigation into antenatal pathways leading to neonatal stroke and other focal lesions.