[Source: British Medical Journal, full page: (LINK). Abstract, edited.]
Prevalence of microcephaly in Europe: population based study
BMJ 2016; 354 / doi: http://dx.doi.org/10.1136/bmj.i4721 / (Published 13 September 2016) / Cite this as: BMJ 2016;354:i4721
Joan K Morris, professor of medical statistics1, Judith Rankin, professor of maternal and perinatal epidemiology2, Ester Garne, consultant paediatrician3, Maria Loane, reader in public health4, Ruth Greenlees, EUROCAT database manager4, Marie-Claude Addor, clinical geneticist5, Larraitz Arriola, epidemiologist6, Ingeborg Barisic, professor of paediatrics and medical genetics7, Jorieke E H Bergman, clinical geneticist8, Melinda Csaky-Szunyogh, head of department9, Carlos Dias, coordinator and invited assistant professor10, Elizabeth S Draper, professor of perinatal and paediatric epidemiology11, Miriam Gatt, consultant in public health medicine12, Babak Khoshnood, medical epidemiologist13, Kari Klungsoyr, professor14, Jennifer J Kurinczuk, director15, Catherine Lynch, specialist in public health medicine16, Robert McDonnell, consultant in public health medicine17, Vera Nelen, director18, Amanda J Neville, senior research fellow19, Mary T O’Mahony, specialist in public health medicine20, Anna Pierini, researcher21, Hanitra Randrianaivo, scientific director22, Anke Rissmann, head of department23, David Tucker, CARIS manager24, Christine Verellen-Dumoulin, professor25, Hermien E K de Walle, senior epidemiologist8, Diana Wellesley, consultant and honorary senior lecturer in clinical genetics26, Awi Wiesel, head of epidemiology27, Helen Dolk, professor of epidemiology and health services research4
Author affiliations: 1Wolfson Institute of Preventive Medicine, Queen Mary University of London, London, UK; 2Institute of Health and Society, Newcastle University, Newcastle upon Tyne, UK; 3Paediatric Department, Hospital Lillebaelt, Kolding, Denmark; 4University of Ulster, Newtownabbey, Co Antrim, Northern Ireland, UK; 5Division of Medical Genetics, Lausanne, Switzerland; 6Public Health Division of Gipuzkoa, Instituto BIO-Donostia, Basque Government, CIBER Epidemiologia y Salud Publica – CIBERESP, Spain; 7Children’s Hospital Zagreb, Medical School University of Zagreb, Zagreb, Croatia; 8University of Groningen, University Medical Centre Groningen, Department of Genetics, Groningen, Netherlands; 9National Public Health and Medical Officer Service, Hungarian Congenital Abnormality Registry, Budapest, Hungary; 10Centro de Estudos e registo de A C, Lisbon, Portugal; 11University of Leicester, Leicester, UK; 12Department of Health Information and Research, Guardamangia, Malta
13INSERM, Paris, France; 14Department of Global Public Health and Primary Care, University of Bergen, and Medical Birth Registry of Norway, Norwegian Institute of Public Health, Bergen, Norway; 15National Perinatal Epidemiology Unit, University of Oxford, Oxford, UK; 16Health Service Executive, Kilkenny, Republic of Ireland; 17Health Service Executive, Dublin, Republic of Ireland; 18Provincial Institute for Hygiene, Antwerp, Belgium; 19IMER Registry, Centre for Clinical and Epidemiological Research, University of Ferrara and Azienda Ospedaliero- Universitaria di Ferrara, Ferrara, Italy; 20Health Service Executive, Cork, Republic of Ireland; 21CNR Institute of Clinical Physiology, Pisa, Italy; 22Registre des Malformations Congenitales de la Reunion, Saint-Pierre, Reunion; 23Malformation Monitoring Centre Saxony-Anhalt, Medical Faculty Otto-von-Guericke University Magdeburg, Magdeburg, Germany; 24Public Health Wales, Swansea, UK; 25Institut de Pathologie at de Genetique, Charleroi, Belgium; 26University of Southampton and Wessex Clinical Genetics Service, Southampton, UK; 27Birth Registry Mainz Model, University Medical Centre of Johannes Gutenberg University, Mainz, Germany
Correspondence to: J Morris email@example.com
Accepted 30 August 2016
To provide contemporary estimates of the prevalence of microcephaly in Europe, determine if the diagnosis of microcephaly is consistent across Europe, and evaluate whether changes in prevalence would be detected using the current European surveillance performed by EUROCAT (the European Surveillance of Congenital Anomalies).
Questionnaire and population based observational study.
24 EUROCAT registries covering 570 000 births annually in 15 countries.
Cases of microcephaly not associated with a genetic condition among live births, fetal deaths from 20 weeks’ gestation, and terminations of pregnancy for fetal anomaly at any gestation.
Main outcome measures
Prevalence of microcephaly (1 Jan 2003-31 Dec 2012) analysed with random effects Poisson regression models to account for heterogeneity across registries.
16 registries responded to the questionnaire, of which 44% (7/16) used the EUROCAT definition of microcephaly (a reduction in the size of the brain with a skull circumference more than 3 SD below the mean for sex, age, and ethnic origin), 19% (3/16) used a 2 SD cut off, 31% (5/16) were reliant on the criteria used by individual clinicians, and one changed criteria between 2003 and 2012. Prevalence of microcephaly in Europe was 1.53 (95% confidence interval 1.16 to 1.96) per 10 000 births, with registries varying from 0.4 (0.2 to 0.7) to 4.3 (3.6 to 5.0) per 10 000 (χ2=338, df=23, I2=93%). Registries with a 3 SD cut off reported a prevalence of 1.74 per 10 000 (0.86 to 2.93) compared with those with the less stringent 2 SD cut off of 1.21 per 10 000 (0.21 to 2.93). The prevalence of microcephaly would need to increase in one year by over 35% in Europe or by over 300% in a single registry to reach statistical significance (P<0.01).
EUROCAT could detect increases in the prevalence of microcephaly from the Zika virus of a similar magnitude to those observed in Brazil. Because of the rarity of microcephaly and discrepant diagnostic criteria, however, the smaller increases expected in Europe would probably not be detected. Clear diagnostic criteria for microcephaly must be adopted across Europe.
Keywords: Research; Abstracts; Microcephaly; European Region.