REVIEW Angela Schoetzau á Ulrike Gehring á H.-Erich Wichmann Prospective cohort studies using hydrolysed formulas for allergy prevention in atopy-prone newborns: a systematic review Received: 17 May 2000 / Accepted: 30 January 2001 Abstract The aim of this study is to give a systematic overview on publications having investigated the allergy preventive eect of extensively and/or partially hydrolysed infant formulas. Publications were searched by several strategies. Inclusion criteria were: pro- spective cohort study, randomisation, family history of atopy of the subjects, follow-up for at least the 1st year of life. Studies were described systematically as to methods, study participants, interventions and co-interventions, and study outcomes. The methodologi- cal quality was judged according to an instrument assessing the reduction of bias score between 0 and 7 points). Data of studies having examined partial hydrolysates are pre- sented as odds ratios. Of 16 studies found, 10 ful®lled the inclusion criteria. Study designs showed considerable dierences as to methods, intervention and co-intervention proce- dures and de®nition of outcomes. Methodological quality varied between 0 and 6 points. The comparison of exclusively test- and control formula-fed groups showed a uniform tendency towards allergy protection in studies with partial hydrolysates. Study results on the eect of extensive hydrolysates were not comparable because of major dierences in study designs. Conclusion More well-designed studies with an adequate statistical power are needed to compare the allergy preventive eect of partially and extensively hydrolysed formulas with a standard infant formula. Key words Allergy prevention á Hydrolysed formula á Atopic disease Abbreviations eHF extensively hydrolysed formula á pHF partially hydrolysed formula Introduction Within the last decade, dietary recommendations have been proposed for newborns with a family history of atopy to prevent early sensitisation to cow's milk protein and other food allergens and the development of atopic diseases [1, 3, 4, 15, 16, 36, 41]. In a joint statement of the European Society for Paediatric Allergology and Clinical Immunology ESPACI) Committee on Hypo- allergenic Formulas and the European Society for Pae- diatric Gastroenterology, Hepatology and Nutrition ESPGHAN) Committee on Nutrition [19] the following advice for prevention of adverse reactions to food pro- teins were given: 1) exclusive breast feeding during the Eur J Pediatr 2001) 160: 323±332 Ó Springer-Verlag 2001 A. Schoetzau &) á H.-E. Wichmann GSF ± National Research Centre for Environment and Health, Institute of Epidemiology, GebaÈude 56, IngolstaÈdter Landstrasse 1, 85764 Neuherberg, Germany Tel.: +49-89-31874481; Fax: +49-89-31873201 e-mail: schoetzau@gsf.de U. Gehring á H.-E. Wichmann Ludwig-Maximilians-University of Munich, Institute of Medical Data Management, Biometrics and Epidemiology, Department of Epidemiology, Munich, Germany This study was supported by the Federal Ministry for Education, Science, Research, and Technology, Grant No. 01 EE 9404.