Browsing by Author "Khoshnood, Babak"
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- Amniotic band syndrome and limb body wall complex in Europe 1980-2019Publication . Bergman, Jorieke E.H.; Barišić, Ingeborg; Addor, Marie‐Claude; Braz, Paula; Cavero‐Carbonell, Clara; Draper, Elizabeth S.; Echevarría‐González‐de‐Garibay, Luis J.; Gatt, Miriam; Haeusler, Martin; Khoshnood, Babak; Klungsøyr, Kari; Kurinczuk, Jennifer J.; Latos‐Bielenska, Anna; Luyt, Karen; Martin, Danielle; Mullaney, Carmel; Nelen, Vera; Neville, Amanda J.; O'Mahony, Mary T.; Perthus, Isabelle; Pierini, Anna; Randrianaivo, Hanitra; Rankin, Judith; Rissmann, Anke; Rouget, Florence; Sayers, Gerardine; Schaub, Bruno; Stevens, Sarah; Tucker, David; Verellen‐Dumoulin, Christine; Wiesel, Awi; Gerkes, Erica H.; Perraud, Annie; Loane, Maria A.; Wellesley, Diana; de Walle, Hermien E.K.Amniotic band syndrome (ABS) and limb body wall complex (LBWC) have an overlapping phenotype of multiple congenital anomalies and their etiology is unknown. We aimed to determine the prevalence of ABS and LBWC in Europe from 1980 to 2019and to describe the spectrum of congenital anomalies. In addition, we investigated maternal age and multiple birth as possible risk factors for the occurrence of ABS and LBWC. We used data from the European surveillance of congenital anomalies (EUROCAT) network including data from 30 registries over 1980–2019. We included all pregnancy outcomes, including live births, stillbirths, and terminations of pregnancy for fetal anomalies. ABS and LBWC cases were extracted from the central EUROCAT database using coding information responses from the registries. In total, 866 ABS cases and 451 LBWC cases were included in this study. The mean prevalence was 0.53/10,000 births for ABS and 0.34/10,000 births for LBWC during the 40 years. Prevalence of both ABS and LBWC was lower in the 1980s and higher in the United Kingdom. Limb anomalies and neural tube defects were commonly see in ABS, whereas in LBWC abdominal and thoracic wall defects and limb anomalies were most prevalent. Twinning was confirmed as a risk factor for both ABS and LBWC. This study includes the largest cohort of ABS and LBWC cases ever reported over a large time period using standardized EUROCAT data. Prevalence, clinical characteristics, and the phenotypic spectrum are described, and twinning is confirmed as a risk factor.
- Ethics and legal requirements for data linkage in 14 European countries for children with congenital anomaliesPublication . Claridge, Hugh; Tan, Joachim; Loane, Maria; Garne, Ester; Barisic, Ingeborg; Cavero-Carbonell, Clara; Matias Dias, Carlos; Gatt, Miriam; Jordan, Susan; Khoshnood, Babak; Kiuru-Kuhlefelt, Sonja; Klungsoyr, Kari; Mokoroa Carollo, Olatz; Nelen, Vera; Neville, Amanda J.; Pierini, Anna; Randrianaivo, Hanitra; Rissmann, Anke; Tucker, David; de Walle, Hermien; Wertelecki, Wladimir; Morris, Joan K.Introduction: Linking healthcare data sets can create valuable resources for research, particularly when investigating rare exposures or outcomes. However, across Europe, the permissions processes required to access data can be complex. This paper documents the processes required by the EUROlinkCAT study investigators to research the health and survival of children with congenital anomalies in Europe. Methods: Eighteen congenital anomaly registries in 14 countries provided information on all the permissions required to perform surveillance of congenital anomalies and to link their data on live births with available vital statistics and healthcare databases for research. Small number restrictions imposed by data providers were also documented. Results: The permissions requirements varied substantially, with certain registries able to conduct congenital anomaly surveillance as part of national or regional healthcare provision, while others were required to obtain ethics approvals or informed consent. Data linkage and analysis for research purposes added additional layers of complexity for registries, with some required to obtain several permissions, including ethics approvals to link the data. Restrictions relating to small numbers often resulted in a registry's data on specific congenital anomalies being unusable. Conclusion: The permissions required to obtain and link data on children with congenital anomalies varied greatly across Europe. The variation and complexity present a significant obstacle to the use of such data, especially in large data linkage projects. Furthermore, small number restrictions severely limited the research that could be performed for children with specific rare congenital anomalies.
- Long term trends in prevalence of neural tube defects in Europe: population based studyPublication . Khoshnood, Babak; Loane, Maria; Walle, Hermien de; Arriola, Larraitz; Addor, Marie-Claude; Barisic, Ingeborg; Beres, Judit; Bianchi, Fabrizio; Dias, Carlos Matias; Draper, Elizabeth; Garne, Ester; Gatt, Miriam; Haeusler, Martin; Klungsoyr, Kari; Latos-Bielenska, Anna; Lynch, Catherine; McDonnell, Bob; Nelen, Vera; Neville, Amanda J.; O’Mahony, Mary T.; Queisser-Luft, Annette; Rankin, Judith; Rissmann, Anke; Ritvanen, Annukka; Rounding, Catherine; Sipek, Antonin; Tucker, David; Verellen-Dumoulin, Christine; Wellesley, Diana; Dolk, HelenStudy question: What are the long term trends in the total (live births, fetal deaths, and terminations of pregnancy for fetal anomaly) and live birth prevalence of neural tube defects (NTD) in Europe, where many countries have issued recommendations for folic acid supplementation but a policy for mandatory folic acid fortification of food does not exist? Methods: This was a population based, observational study using data on 11 353 cases of NTD not associated with chromosomal anomalies, including 4162 cases of anencephaly and 5776 cases of spina bifida from 28 EUROCAT (European Surveillance of Congenital Anomalies) registries covering approximately 12.5 million births in 19 countries between 1991 and 2011. The main outcome measures were total and live birth prevalence of NTD, as well as anencephaly and spina bifida, with time trends analysed using random effects Poisson regression models to account for heterogeneities across registries and splines to model non-linear time trends. Summary answer and limitations: Overall, the pooled total prevalence of NTD during the study period was 9.1 per 10 000 births. Prevalence of NTD fluctuated slightly but without an obvious downward trend, with the final estimate of the pooled total prevalence of NTD in 2011 similar to that in 1991. Estimates from Poisson models that took registry heterogeneities into account showed an annual increase of 4% (prevalence ratio 1.04, 95% confidence interval 1.01 to 1.07) in 1995-99 and a decrease of 3% per year in 1999-2003 (0.97, 0.95 to 0.99), with stable rates thereafter. The trend patterns for anencephaly and spina bifida were similar, but neither anomaly decreased substantially over time. The live birth prevalence of NTD generally decreased, especially for anencephaly. Registration problems or other data artefacts cannot be excluded as a partial explanation of the observed trends (or lack thereof) in the prevalence of NTD. What this study adds: In the absence of mandatory fortification, the prevalence of NTD has not decreased in Europe despite longstanding recommendations aimed at promoting peri-conceptional folic acid supplementation and existence of voluntary folic acid fortification.
- Maternal age and the prevalence of congenital heart defects in Europe, 1995–2015: A register‐based studyPublication . Mamasoula, Chrysovalanto; Bigirumurame, Theophile; Chadwick, Thomas; Addor, Marie‐Claude; Cavero‐Carbonell, Clara; Matias Dias, Carlos; Echevarría‐González‐de‐Garibay, Luis‐Javier; Gatt, Miriam; Khoshnood, Babak; Klungsoyr, Kari; Randall, Kay; Stoianova, Sylvia; Haeusler, Martin; Nelen, Vera; Neville, Amanda J.; Perthus, Isabelle; Pierini, Anna; Bertaut‐Nativel, Bénédicte; Rissmann, Anke; Rouget, Florence; Schaub, Bruno; Tucker, David; Wellesley, Diana; Zymak‐Zakutnia, Natalya; Barisic, Ingeborg; de Walle, Hermien E.K.; Lanzoni, Monica; Sayers, Gerardine; Mullaney, Carmel; Pennington, Lindsay; Rankin, JudithBackground: Evidence on the direction and strength of association between maternal age and the prevalence of congenital heart defects (CHD) in different age group categories is conflicting. Some studies have illustrated different trends with an increase in prevalence in younger and older age groups while other studies have reported a linear relationship. Given the increase in maternal age over recent years, it is important to study the CHD prevalence by maternal age. Objectives: To examine the association between maternal age and the prevalence of CHD in Europe between 1995 and 2015 using population-based data from 24 registries belonging to the European Surveillance of Congenital Anomalies (EUROCAT) network. Methods: Associations over time of all nonsyndromic CHD according to maternal age category and for three CHD severity groupings (severity group I: very severe; severity group II: severe; severity group III: less severe) were examined using Bayesian multilevel Poisson regression modeling. Further subgroup analyses were undertaken within four maternal age-bands: ≤24, 25–29, 30–34 and 35–44 years. Descriptive summaries are also presented. Results: There were 51,608 nonsyndromic CHD cases in Europe over the 20-year study period. Total prevalence for all CHD combined was increased for younger mothers (≤24 years) and for mothers 35–44 years of age when compared with mothers aged 25–29 years (reference group) (IRR: 1.05, 95% CI: 1.02, 1.07). The total prevalence was increased for severity group I (very severe) only for younger mothers compared to those aged 25–29 years (IRR: 1.14, 95% CI: 1.04, 1.23). We found an increased prevalence of the following CHD subtypes: double outlet right ventricle (IRR:1.33, 95% CI: 1.09, 1.60), hypoplastic left heart syndrome (IRR: 1.18, 95% CI: 1.05, 1.32), hypoplastic right heart syndrome (IRR: 1.41, 95% CI: 1.05, 1.84), atrioventricular septal defect (IRR: 1.15, 95% CI: 1.01, 1.32), coarctation of aorta (IRR: 1.15, 95% CI: 1.03, 1.28) and atrial septal defect (IRR: 1.08, 95% CI: 1.02, 1.13). For older mothers (35–44 years) compared to the reference category, we observed an increased risk in the prevalence for severity group II (IRR: 1.09, 95% CI: 1.03, 1.14), severity group III (IRR: 1.05, 95% CI: 1.01, 1.08) and an increased prevalence of the CHD subtypes: Pulmonary valve stenosis (IRR: 1.22, 95% CI: 1.09, 1.34), ASD (IRR: 1.07, 95% CI: 1.02, 1.13), CoA (IRR: 1.18, 95% CI: 1.06, 1.32) and Tetralogy of Fallot (IRR: 1.14, 95% CI: 1.01, 1.28). Finally, for all age categories compared to the reference category, different associations of ASD and an increased prevalence of CoA was also observed. Conclusions: Based on data for cases of CHD from 24 European populationbased registries, evidence of a positive association between maternal age and the total prevalence of CHD for younger (≤24 years old) and older (35–44 years old) mothers was observed. The results suggest that young maternal age (≤24 years old) is a factor associated with severe CHD phenotypes while a positive association between advanced maternal age (35–44 years old) and mild CHD phenotypes was observed.
- Maternal risk factors for the VACTERL association: a EUROCAT case-control studyPublication . van de Putte, Romy; van Rooij, Iris A.L.M.; Haanappel, Cynthia P.; Marcelis, Carlo L.M.; Brunner, Han G.; Addor, Marie‐Claude; Cavero‐Carbonell, Clara; Matias Dias, Carlos; Draper, Elizabeth S.; Etxebarriarteun, Larraitz; Gatt, Miriam; Khoshnood, Babak; Kinsner‐Ovaskainen, Agnieszka; Klungsoyr, Kari; Kurinczuk, Jenny J.; Latos‐Bielenska, Anna; Luyt, Karen; O'Mahony, Mary T.; Miller, Nicola; Mullaney, Carmel; Nelen, Vera; Neville, Amanda J.; Perthus, Isabelle; Pierini, Anna; Randrianaivo, Hanitra; Rankin, Judith; Rissmann, Anke; Rouget, Florence; Schaub, Bruno; Tucker, David; Wellesley, Diana; Wiesel, Awi; Zymak‐Zakutnia, Natalya; Loane, Maria; Barisic, Ingeborg; Walle, Hermien E.K.; Bergman, Jorieke E.H.; Roeleveld, NelBackground: The VACTERL association (VACTERL) is the nonrandom occurrence of at least three of these congenital anomalies: vertebral, anal, cardiac, tracheoesophageal, renal, and limb anomalies. Despite suggestions for involvement of several genes and nongenetic risk factors from small studies, the etiology of VACTERL remains largely unknown. Objective: To identify maternal risk factors for VACTERL in offspring in a large European study. Methods: A case-control study was performed using data from 28 EUROCAT registries over the period 1997-2015 with case and control ascertainment through hospital records, birth and death certificates, questionnaires, and/or postmortem examinations. Cases were diagnosed with VACTERL, while controls had a genetic syndrome and/or chromosomal abnormality. Data collected included type of birth defect and maternal characteristics, such as age, use of assisted reproductive techniques (ART), and chronic illnesses. Multivariable logistic regression analyses were performed to estimate confounder adjusted odds ratios (aOR) with 95% confidence intervals (95% CI). Results: The study population consisted of 329 VACTERL cases and 49,724 controls with recognized syndromes or chromosomal abnormality. For couples who conceived through ART, we found an increased risk of VACTERL (aOR 2.3 [95% CI 1.3, 3.9]) in offspring. Pregestational diabetes (aOR 3.1 [95% CI 1.1, 8.6]) and chronic lower obstructive pulmonary diseases (aOR 3.9 [95% CI 2.2, 6.7]) also increased the risk of having a child with VACTERL. Twin pregnancies were not associated with VACTERL (aOR 0.6 [95% CI 0.3, 1.4]). Conclusion: We identified several maternal risk factors for VACTERL in offspring befitting a multifactorial etiology.
- Meckel–Gruber Syndrome: a population-based study on prevalence, prenatal diagnosis, clinical features, and survival in EuropePublication . Barisc, Ingeborg; Boban, Ljubica; Loane, Maria; Garne, Ester; Wellesley, Diana; Calzolari, Elisa; Dolk, Helen; Addor, Marie-Claude; Bergman, Jorieke E.H.; Braz, Paula; Draper, Elizabeth S.; Haeusler, Martin; Khoshnood, Babak; Klungsoyr, Kari; Pierini, Anna; Queisser-Luft, Annette; Rankin, Judith; Rissmann, Anke; Verellen-Dumoulin, ChristineMeckel–Gruber Syndrome is a rare autosomal recessive lethal ciliopathy characterized by the triad of cystic renal dysplasia,occipital encephalocele and postaxial polydactyly. We present the largest population-based epidemiological study to date using data provided by the European Surveillance of Congenital Anomalies (EUROCAT) network. The study population consisted of 191 cases of MKS identified between January 1990 and December 2011 in 34 European registries. The mean prevalence was 2.6 per 100 000 births in a subset of registries with good ascertainment. The prevalence was stable over time, but regional differences were observed. There were 145 (75.9%) terminations of pregnancy after prenatal diagnosis, 13 (6.8%) fetal deaths, 33 (17.3%) live births. In addition to cystic kidneys (97.7%), encephalocele (83.8%) and polydactyly(87.3%), frequent features include other central nervous system anomalies (51.4%), fibrotic/cystic changes of the liver (65.5%) of cases with post mortem examination) and orofacial clefts (31.8%). Various other anomalies were present in 64 (37%) patients. As nowadays most patients are detected very early in pregnancy when liver or kidney changes may not yet be developed or may be difficult to assess, none of the anomalies should be considered obligatory for the diagnosis. Most cases (90.2%) are diagnosed prenatally at 14.3±2.6 (range 11–36) gestational weeks and pregnancies are mainly terminated, reducing the number of LB to one-fifth of the total prevalence rate. Early diagnosis is important for timely counseling of affected couples regarding the option of pregnancy termination and prenatal genetic testing in future pregnancies.
- Paper 2: EUROCAT public health indicators for congenital anomalies in EuropePublication . Khoshnood, Babak; Greenlees, Ruth; Loane, Maria; Dolk, Helen; EUROCAT Project Management Committee; EUROCAT Working GroupThe purpose of this article is to present the specific public health indicators recently developed by EUROCAT that aim to summarize important aspects of the public health impact of congenital anomalies in a few quantitative measures. METHODS: The six indicators are: (1) congenital anomaly perinatal mortality, (2) congenital anomaly prenatal diagnosis prevalence, (3) congenital anomaly termination of pregnancy, (4) Down syndrome livebirth prevalence, (5) congenital anomaly pediatric surgery, and (6) neural tube defects (NTD) total prevalence. Data presented for this report pertained to all cases (livebirths, fetal deaths, or stillbirths after 20 weeks of gestation and terminations of pregnancy for fetal anomaly [TOPFA]) of congenital anomaly from 27 full member registries of EUROCAT that could provide data for at least 3 years during the period 2004 to 2008. Prevalence of anomalies, prenatal diagnosis, TOPFA, pediatric surgery, and perinatal mortality were calculated per 1000 births. RESULTS: The overall perinatal mortality was approximately 1.0 per 1000 births for EUROCAT registries with almost half due to fetal and the other half due to first week deaths. There were wide variations in perinatal mortality across the registries with the highest rates observed in Dublin and Malta, registries in countries where TOPFA are illegal, and in Ukraine. The overall perinatal mortality across EUROCAT registries slightly decreased between 2004 and 2008 due to a decrease in first week deaths. The prevalence of TOPFA was fairly stable at about 4 per 1000 births. There were variations in livebirth prevalence of cases typically requiring surgery across the registries; however, for most registries this prevalence was between 3 and 5 per 1000 births. Prevalence of NTD decreased by about 10% from 1.05 in 2004 to 0.94 per 1000 in 2008. CONCLUSION: It is hoped that by publishing the data on EUROCAT indicators, the public health importance of congenital anomalies can be clearly summarized to policy makers, the need for accurate data from registries emphasized, the need for primary prevention and treatment services highlighted, and the impact of current services measured.
- Paper 6 - EUROCAT Member Registries: Organization and ActivitiesPublication . Greenless, Ruth; Neville, Amanda; Addor, Marie–Clauder; Amar, Emmanuelleder; Arriola, Larraitz; Bakker, Marian; Barisic, Ingeborg; Boyd, Patricia A.; Calzolari, Elisa; Doray, Berenice; Draper, Elizabeth; Vollset, Stein Emili; Garne, Ester; Gatt, Miriam; Haeusler, Martin; Kallen, Karin; Khoshnood, Babak; Latos–Bielenska, Anna; Martinez–Friasa, Maria–Luisa; Materna–Kiryluk, Anna; Dias, Carlos Matias; McDonnell, Bob; Mullaney, Carmel; Nelen, Vera; O’Mahony, Mary; Pierini, Anna; Queisser–Luft, Annette; Randrianaivo–Ranjatoélina, Hanitra; Rankin, Judith; Rissmann, Anke; Ritvanen, Annukka; Salvador, Joaquin; Sipek, Antonin; Tucker, David; Verellen–Dumoulin, Christine; Wellesley, Diana; Werteleckir, WladimirEUROCAT is a network of population-based congenital anomaly registries providing standardized epidemiologic information on congenital anomalies in Europe. There are three types of EUROCAT membership: full, associate, or affiliate. Full member registries send individual records of all congenital anomalies covered by their region. Associate members transmit aggregate case counts for each EUROCAT anomaly subgroup by year and by type of birth. This article describes the organization and activities of each of the current 29 full member and 6 associate member registries of EUROCAT. METHODS: Each registry description provides information on the history and funding of the registry, population coverage including any changes in coverage over time, sources for ascertaining cases of congenital anomalies, and upper age limit for registering cases of congenital anomalies. It also details the legal requirements relating to termination of pregnancy for fetal anomalies, the definition of stillbirths and fetal deaths, and the prenatal screening policy within the registry. Information on availability of exposure information and denominators is provided. The registry description describes how each registry conforms to the laws and guidelines regarding ethics, consent, and confidentiality issues within their own jurisdiction. Finally, information on electronic and web-based data capture, recent registry activities, and publications relating to congenital anomalies, along with the contact details of the registry leader, are provided. CONCLUSIONS: The registry description gives a detailed account of the organizational and operational aspects of each registry and is an invaluable resource that aids interpretation and evaluation of registry prevalence data.
- Prevalence of congenital heart defects in Europe, 2008-2015: A registry‐based studyPublication . Mamasoula, Chrysovalanto; Addor, Marie‐Claude; Carbonell, Clara Cavero; Matias Dias, Carlos; Echevarría‐González‐de‐Garibay, Luis‐Javier; Gatt, Miriam; Khoshnood, Babak; Klungsoyr, Kari; Randall, Kay; Stoianova, Sylvia; Haeusler, Martin; Nelen, Vera; Neville, Amanda J.; Perthus, Isabelle; Pierini, Anna; Bertaut‐Nativel, Bénédicte; Rissmann, Anke; Rouget, Florence; Schaub, Bruno; Tucker, David; Wellesley, Diana; Zymak‐Zakutnia, Natalya; Barisic, Ingeborg; de Walle, Hermien E.K.; Lanzoni, Monica; Mullaney, Carmel; Pennington, Lindsay; Rankin, JudithBackground: The total prevalence of congenital heart defects (CHDs) varies by populations and over time. Studies that examine trends in the prevalence of CHD in different regions may shed light on our understanding of the occurrence of CHD and the impact of different risk factors. Objectives: To examine trends in total and live birth prevalence of nonsyndromic CHD in Europe between the years 2008 and 2015 and to investigate if the decreasing trend reported by previous studies is continuing. Methods: Cases of CHD delivered between January 1, 2008 and December 31, 2015 notified to 25 population-based EUROCAT (European Surveillance of Congenital Anomalies) registries in 14 countries, formed the population-based case-series. Prevalence (total/live) rates and 95% confidence intervals were calculated as the number of cases per 10,000 births (live and stillbirths). Time trends in prevalence of all nonsyndromic CHDs and for three CHD severity groups (very severe, severe, and less severe) were plotted using a Poisson regression multilevel approach. Results: The total prevalence of nonsyndromic CHD was 57.1 per 10,000 births (live births and stillbirths) for the 8-year period and remained stable across the three CHD severity groups while the live birth prevalence was 60.2 per 10,000 births. There was considerable variation in the reported total CHD prevalence and the direction of trends by registry. A decreasing prevalence ofCHD was observed for the Norway and England/Wales registries, whereas the CHD prevalence increased for registries in Italy and Croatia. Conclusions: The total prevalence of CHD in Europe between the years 2008 and 2015 remained stable for all CHD and across the three CHD severity groups. The decreasing trend reported by previous studies has not continued. However, we found significant differences in the total and live birth prevalence by registry.
- Prevalence of microcephaly in Europe: population based studyPublication . Morris, Joan K.; Rankin, Judith; Garne, Ester; Loane, Maria; Greenlees, Ruth; Addor, Marie-Claude; Arriola, Larraitz; Barisic, Ingeborg; Bergman, Jorieke E.H.; Csaky-Szunyogh, Melinda; Dias, Carlos Matias; Draper, Elizabeth S.; Gatt, Miriam; Khoshnood, Babak; Klungsoyr, Kari; Kurinczuk, Jennifer J.; Lynch, Catherine; McDonnell, Robert; Nelen, Vera; Neville, Amanda J.; O'Mahony, Mary T.; Pierini, Anna; Randrianaivo, Hanitra; Rissmann, Anke; Tucker, David; Verellen-Dumoulin, Christine; de Walle, Hermien E.K.; Wellesley, Diana; Wiesel, Awi; Dolk, HelenObjectives: 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). Design: Questionnaire and population based observational study. Setting: 24 EUROCAT registries covering 570 000 births annually in 15 countries. Participants: 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. Results: 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). Conclusions: 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.