Lactate in the foetal brain: detection and implications Ariadne M Roelants-van Rijn, MD 1 , Floris Groenendaal, MD PhD 1 , Philip Stoutenbeek, MD PhD 2 and Jeroen van der Grond, PhD 3 Departments of Neonatology 1 , Gynaecology and Obstetrics 2 and Radiology 3 , Wilhelmina Children’s Hospital, University Medical Centre, Utrecht, The Netherlands Roelants-van Rijn AM, Groenendaal F, Stoutenbeek P, van der Grond J. Lactate in the foetal brain: detection and implications. Acta Pædiatr 2004; 93: 937–940. Stockholm. ISSN 0803-5253 Background and methods: In six hydrocephalic foetuses (gestational age 29–38 wk), proton MR spectroscopy ( 1 H-MRS) was performed in the basal ganglia for detection of lactate in vivo. Results: Lactate was present in two foetal brains, absent in two and not detectable because of movement in two. Conclusion: With adequate immobilization of the foetus, 1 H-MRS can be used for detection of foetal brain lactate. Key words: Proton MR spectroscopy, brain metabolism, lactate, foetus, hydrocephalus F Groenendaal, Department of Neonatology, Wilhelmina Children’s Hospital, University Medical Centre Utrecht, Lundlaan 6, 3584 EA Utrecht, The Netherlands (Tel. 31 30 250 4545, fax. 31 30 250 5320, e-mail. f.groenendaal@wkz.azu.nl) Ultrasonography is the standard, convenient and in- expensive way to collect information about the foetal brain, but does not offer information about the biochemical status. In full-term, asphyxiated newborns, cerebral metabolism, examined using proton magnetic resonance spectroscopy ( 1 H-MRS), has proven to be of prognostic value for neurodevelopment after hypoxia- ischaemia. Both a decrease of N-acetyl-aspartate (NAA), a neuronal marker, and an increase of lactate, the end-product of the anaerobic glycolysis, predict an adverse neurodevelopmental outcome (1). Previous studies investigating the cerebral metabolism in mature human foetuses have shown two major problems of foetal 1 H-MRS: firstly, the impossibility to detect lactate or, in a number of cases, the impossibility to detect NAA due to large lipid resonances (2, 3); and secondly, the signal-to-noise is generally low, which may lead to a poor quantification of the metabolite signals or even to an erroneous assignment of the individual resonances (2–4). Other resonances such as choline (Cho) and (phospho-) creatine (Cr) can be visualized more easily. At present, the detection of lactate in the foetal brain has only been described in animal studies. Van Cappellen van Walsum et al. detected lactate during hypoxia in foetal sheep, but in this experiment a hysterectomy was performed and the foetal head was exteriorized for MR examination (5). The aim of the present study was to develop an MRI/ 1 H-MRS method that is able to detect lactate in the human foetus in utero. Patients and methods Six consecutive patients were selected because of extensive hydrocephalus of the foetus on ultrasound. MRI studies were performed for detailed brain imaging followed by 1 H-MRS examination. These hydrocepha- lic foetuses had an MRI for clinical reasons. Gestational age ranged from 29–36 wk (34 ± 3 wk). One hour before the examination, 10 mg diazepam was adminis- tered to the mother for sedation of the foetus, which we consider a safe method for both mother and foetus (6). The study was approved by the Ethics Committee of the University Medical Centre Utrecht. Informed consent of the parents was obtained in all cases. MR examinations were performed in a whole-body Philips ACS-NT Intera system (Philips, Best, The Netherlands) operating at 1.5 Tesla. A quadrature body coil was used for radio-frequency transmission and signal reception in both MRI and 1 H-MRS. MRI MRI included sagittal, axial and coronal turbo-spin- echo T2-weighted images. Repetition time/echo time (TR/TE) 16577/100 ms, field of view 400 mm 2 , rectan- gular field of view 70%, scan percentage 80%, matrix size 256  256, turbo-spin-echo factor 86, 22 sections with a thickness of 5 mm and a 1-mm section gap, number of average 1. The total scan time was 17 s. 1 H-MRS For 1 H-MRS, a volume of interest (VOI) was placed in  2004 Taylor & Francis. ISSN 0803-5253 Acta Pñdiatr 93: 937±940. 2004 DOI 10.1080/08035250410031297