PT - JOURNAL ARTICLE AU - Joan Morris AU - Ieda M Orioli AU - Adriana Benavides-Lara AU - María de la Paz Barboza-Arguello AU - Maria Aurora Canessa Tapia AU - Giovanny Vinícius Araújo de França AU - Boris Groisman AU - Jorge Holguin AU - Paula Margarita Hurtado-Villa AU - Marisol Ibarra Ramirez AU - Cecilia Mellado AU - Rosa Pardo AU - Dania Maria Pastora Bucardo AU - Catherin Rodríguez AU - Ignacio Zarante AU - Elizabeth Limb AU - Helen Dolk TI - Prevalence of microcephaly: the Latin American Network of Congenital Malformations 2010–2017 AID - 10.1136/bmjpo-2021-001235 DP - 2021 Nov 01 TA - BMJ Paediatrics Open PG - e001235 VI - 5 IP - 1 4099 - http://bmjpaedsopen.bmj.com/content/5/1/e001235.short 4100 - http://bmjpaedsopen.bmj.com/content/5/1/e001235.full SO - BMJ Paediatrics Open2021 Nov 01; 5 AB - Objective The Latin American Network of Congenital Malformations: ReLAMC was established in 2017 to provide accurate congenital anomaly surveillance. This study used data from ReLAMC registries to quantify the prevalence of microcephaly from 2010 to 2017 (before, during and after the Zika virus epidemic).Design Nine ReLAMC congenital anomaly registries provided case-level data or aggregate data for any live births, still births or terminations of pregnancy with microcephaly. Births to pregnant women infected with Zika virus first occurred in Brazil in 2015, and in the remaining registry areas in 2016 with the exception of Chile that did not experience Zika virus. Therefore the prevalence of microcephaly for 2010–2014 and individual years 2015, 2016 and 2017 was estimated using multilevel random effect Poisson models. Clinical classification and characteristics of the cases were compared pre and post Zika for all centres providing individual case-level data.Results The prevalence of microcephaly for all registries excluding Brazil was 2.3 per 10 000 (95% CI 2.0 to 2.6) for 2010–2014 rising to 5.4 (95% CI 4.8 to 6.0) in 2016 and 5.9 (95% CI 5.3 to 6.6) in 2017. Brazil had a prevalence of 0.6 per 10 000 (95% CI 0.5 to 0.6) in 2010–2014, rising to 5.8 (95% CI 5.6 to 6.1) in 2015, 8.0 (95% CI 7.6 to 8.3) in 2016 and then falling in 2017. Only 29 out of 687 cases of microcephaly were reported as congenital Zika syndrome in countries excluding Brazil.Conclusions The prevalence of microcephaly was influenced both by Zika causing congenital Zika syndrome and by increased reporting awareness.Data may be obtained from a third party and are not publicly available. The authors of this paper cannot release the de-identified participant data analysed in this paper, as the data belong to each registry. Access to the data may be obtained by applying individually to each congenital anomaly registry or to the ReLAMC (Rede Latino Americana de Malformaciones Congénitas) network with a research proposal (relamcoord@gmail.com).