Obstetric risk factors and persistent increases in brain parenchymal echogenicity in preterm infants Arsenio Spinillo, a Alberto Chiara, b Carola Bergante, a Danila Biancheri, a DePaoli Fabiana, a Elisa Fazzi c Objective To assess the risk of persistent ( > 7 days) increases in brain parenchymal echogenicity in preterm infants and their association with known obstetric risk factors. Design Case – control study of prospectively collected data. Setting A University hospital in Northern Italy. Population Eighty-five singleton infants between 24 and 34 weeks of gestation with a cranial ultrasono- graphic diagnosis of persistently increased parenchymal echogenicity without development of cystic degeneration, and 170 control infants with negative cranial ultrasonographic findings. Methods A comparison of the prevalence of selected obstetric risk factors between infants with persistent echo-dense lesions and negative controls. Main outcome measures Odds ratios of persistent echo-dense lesions including first-degree interactions between variables. Results After adjusting for birthweight, logistic regression analysis showed that the only factor associated with an increased risk of persistent brain echo-dense lesions in infants was multiple courses of antenatal steroids (OR ¼ 2.14, 95% CI ¼ 1.11 – 4.15, P ¼ 0.024). In this group, the risk of persistent echo-dense lesions was particularly high in: (i) mothers receiving dexamethasone rather than betamethasone (P value for interaction ¼ 0.015) and (ii) after expectant management of pre-eclampsia or intrauterine growth retardation (P value for interaction ¼ 0.03). Conclusions Multiple doses of antenatal steroids, especially dexamethasone, could influence the prevalence of persistent increases in brain parenchymal echogenicity in preterm infants. INTRODUCTION Brain injury in the premature infant includes periventric- ular leucomalacia and severe intraventricular haemorrhage. 1,2 In recent years, the prevalence of severe intraventricular haemorrhage has decreased significantly, whereas periven- tricular leucomalacia is recognised as the main antecedent of cerebral palsy in immature infants. 3 According to De Vries, 1 the range of cerebral lesions associated with peri- ventricular leucomalacia comprises less severe (but more frequent) persistent echo-dense lesions, and more severe (but less frequent) localised or extensive cystic lesions. The presence in preterm infants of persistent echo-dense cere- bral parenchymal lesions in the first two weeks of life is considered to be due to an ischaemic insult, but an insult which is probably less severe than those resulting in localised or extensive necrosis of white matter with even- tual cystic degeneration. 4 Most of the epidemiological data on antecedent factors for periventricular leucomalacia are related to the cystic form of the disease, whereas the impact of antenatal factors on the occurrence of persistent echo-dense lesions in preterm infants is less clear. 2,5 The aim of this study was to evaluate obstetric antecedents of persistent echo-dense periventricular lesions in preterm infants. METHODS The initial study group included 521 singleton preterm (24–34 completed weeks) infants delivered at our Institute over the study period 1995–2000. Maternal social, demo- graphic and clinical variables were collected at birth and entered into a database. Neonatal variables were collected at discharge from hospital. Except for eight patients excluded from the study, all had gestational age confirmed by an ultrasound scan performed by the 18th week of pregnancy. Fetal growth restriction was diagnosed when abdominal BJOG: an International Journal of Obstetrics and Gynaecology September 2004, Vol. 111, pp. 913–918 D RCOG 2004 BJOG: an International Journal of Obstetrics and Gynaecology www.blackwellpublishing.com/bjog a Department of Obstetrics and Gynecology, IRCCS Policlinico S. Matteo, University of Pavia, Italy b Division of Neonatal Intensive Care, IRCCS Policlinico S. Matteo, Pavia, Italy c Institute of Child Neuropsychiatry, IRCCS C. Mondino, University of Pavia, Italy Correspondence: Dr A. Spinillo, Clinica Ostetrica e Ginecologica, University of Pavia, IRCCS Policlinico S. Matteo P. le Golgi, 2 27100 Pavia, Italy. DOI: 10.1111/j.1471-0528.2004.00229.x