Infants with chromosomal ab-normalities or inborn errors of metabolism were excluded.In 9 patients, the first Hb concentration was measured after a blood transfusion had already been administered immediately af-ter birth. Initial Hb concentrations were therefore estimated, based on the fact that a blood transfusion of 20 ml/kg increases Hb con-centration by approximately 3.0 mmol/l. These estimated values were used as the initial Hb concentrations.Various clinical data of vital organ failure were collected, in-cluding the need for respiratory or circulatory support and the aEEG background pattern.MRI AnalysisMRI in the VU Medical Center was performed on a 1.5-tesla magnet (Siemens Vision, Erlangen, Germany). The MRI protocol included T1, T2 and diffusion-weighted images (DWI). In the Wil-helmina Children’s Hospital, the same sequences were obtained on a 1.5-tesla MRI, and more recently on a 3-tesla MRI (ACS-NT Sys-tem and Achieva, respectively; Philips Medical Systems, Best, the Netherlands).We assessed predefined brain areas on both conventional im-aging and DWI. The MRI score described by Rutherford was used (Appendix 1). The separate areas of interest were scored in three categories: (1) no abnormalities (no abnormalities on T1- and T2-weighted images), (2) mild abnormalities (focal regions of abnor-mal signal intensity) and (3) moderate-to-severe abnormalities (multiple regions of abnormal signal intensity).OutcomeNeurodevelopmental and neuromotor function follow-up were assessed with either the Griffiths Scale of Mental Develop-ment (GMDS), Bayley Scales of Infant Development, ed. 2, Dutch version (BSID-II-NL), or, more recently, Bayley Scales of Infant Development, ed. 3 (BSID-III). In order to enable the comparison of these different developmental tests, Z-scores were calculated for GMDS [performance developmental quotient used for neurode-velopment and the locomotor developmental quotient used for motor development], BSID-II-NL [mental developmental indexPatient characteristicsGestational age, weeks 39 4/7 (36 0/7 – 42 1/7)Birth weight, g 3,200 (1,850 – 4,305)Sex, male 26 (53)Apgar score at 5 min 4 (0 – 1pH (umbilical cord or first pH) 6.96 (6.60 – 7.30)Lactate max. 19.3 (2.9 – 35.0)Hb concentration, mmol/l 4.1 (1.0 – 5.9)Survival 31 (63.3)aEEG performed 42 (86)aEEG background pattern documented 28 (57)MRI performed 25 (51)Survivors with MRI imaging 20 (40.8)Neurodevelopmental assessment of survivors (n = 31) 20 (64.5)Neurodevelopmental assessment and MRI 14 (45.2)Values are given as n (%) or median (range).and psychomotor developmental index], and BSID-III composite score outcomes. Z-scores were calculated as follows: [(score – test mean)/standard deviation (SD)] for each test. Development was classified as either mildly delayed (Z-score ≤–1) or normal (Z-score >–1). If neurodevelopmental tests were not performed, par-ents and/or general practitioners were contacted by phone to ob-tain the most recent status of neurodevelopment.Statistical AnalysisComparisons were made between groups with initial Hb con-centrations ≤3.0 mmol/l and 3.1–6.0 mmol/l, as well as between surviving and deceased patients. Comparisons were also made be-tween groups with and without MRI abnormalities. We used a χ 2 test and the Mann-Whitney U test for categorical and continuous variables, respectively. p < 0.05 was considered statistically signifi-cant. Statistical analyses were performed using SPSS Software Package version 20.ResultsPatient characteristics are presented in table 1. Hb concentrations were measured at birth or within several hours after birth and ranged from 1.0 to 5.9 mmol/l.Aetiology of Neonatal AnaemiaThe most frequent causes of anaemia were foetomater-nal haemorrhage (30.6%) and exsanguination (26.5%) due to vasa or placenta praevia. Less common causes were twin-to-twin transfusion syndrome (8.2%), placental ab-ruption (8.2%), bleeding due to a traumatic delivery Severe Neonatal Anaemia, MRI Findings Neonatology 2016;109:282–288 283 and Neurodevelopmental Outcome DOI: 10.1159/000443320Table 2. Clinical characteristics of survivors versus deceased, and Hb concentration below or above 3.0 mmol/lSurvivors Deceased p Hb <3.0 Hb 3.1 – 6.0 p(n = 31) (n = 18) mmol/l mmol/l (n = 14) (n = 35) Values are given as n (%). BS = Burst suppression; FT = flat trace, χ2 test. Statistically significant differences are in italics. (8.2%), umbilical cord rupture (6.1%), haemolysis (6.1%) and complications during caesarean section (2.0%). In 4.1%, the aetiology remained unknown. As hydrops was not present in any patient, the onset of the severe anaemia was most likely to be (sub)acute. Reticulocyte count data would have been useful to help determine the time of on-set of the anaemia, but these data were not available in most of the infants.Clinical CharacteristicsInvasive mechanical ventilation was required in 85.7%, and non-invasive respiratory support (continuous posi-tive airway pressure) in 14.3%. Circulatory support with vasopressors was needed in 75.5% of the patients. There were no significant differences in the need for vital organ support or mortality between the two Hb concentration groups (table 2).Thirteen patients (31%) had at least one glucose con-centration <2.0 mmol/l. There were no differences in mortality (Fisher’s exact test, p = 0.759), morbidity [Fish-er’s exact test, need for respiratory support p = 0.186, need for circulatory support p = 0.636, and convulsions (either clinical or electrographic) p = 0.612] or neurode-velopment or motor development (χ2, p = 0.954 and p = 0.683, respectively) between normoglycaemic and hypo-glycaemic patients.aEEG CharacteristicsClinical or subclinical seizures were noted in 61.2% of the infants (n = 30). Of these, 43.3% of the infants (n = 13) needed one, and 56.6% (n = 17) needed multiple anti-epi-leptic drugs. Most patients were monitored with aEEG during the first days after birth (n = 42, 86%). In 28 patients, aEEG was available for assessment of the back-ground pattern. The patterns recorded and scored during the first 12 h after birth were used.