OBJECTIVES: To estimate the baseline prevalence and risk factors for microcephaly at birth before the Zika virus epidemic in 2 Brazilian cities. METHODS: We used population-based data from the Brazilian Ribeirão Preto (RP) and São Luís (SL) birth cohort studies of 2010 that included hospital deliveries by resident mothers. The final sample was 7376 live births in RP and 4220 in SL. Gestational age was based on the date of the mother's last normal menstrual period or obstetric ultrasonography, if available. Microcephaly at birth was classified according to the criteria of the International Fetal and Newborn Growth Consortium for the 21st Century and the Brazilian Ministry of Health. Risk factors for microcephaly, proportionate and disproportionate microcephaly, and severe microcephaly were estimated in a hierarchized logistic regression model. RESULTS: According to the International Fetal and Newborn Growth Consortium for the 21st Century definition, the prevalence of microcephaly (>2 SDs below the mean for gestational age and sex) was higher in SL (3.5%) than in RP (2.5%). The prevalence of severe microcephaly (>3 SDs below the mean) was higher in SL (0.7%) than in RP (0.5%). Low maternal schooling, living in consensual union or without a companion, maternal smoking during pregnancy, primiparity, vaginal delivery, and intrauterine growth restriction were consistently associated with microcephaly. The number of cases of microcephaly is grossly underestimated, with an underreporting rate of ∼90%. CONCLUSIONS: The prevalence of severe microcephaly was much higher than expected in both cities. Our findings suggest that microcephaly was endemic in both municipalities before the circulation of the Zika virus.
OBJECTIVES: To estimate the baseline prevalence and risk factors for microcephaly at birth before the Zika virus epidemic in 2 Brazilian cities. METHODS: We used population-based data from the Brazilian Ribeirão Preto (RP) and São Luís (SL) birth cohort studies of 2010 that included hospital deliveries by resident mothers. The final sample was 7376 live births in RP and 4220 in SL. Gestational age was based on the date of the mother's last normal menstrual period or obstetric ultrasonography, if available. Microcephaly at birth was classified according to the criteria of the International Fetal and Newborn Growth Consortium for the 21st Century and the Brazilian Ministry of Health. Risk factors for microcephaly, proportionate and disproportionate microcephaly, and severe microcephaly were estimated in a hierarchized logistic regression model. RESULTS: According to the International Fetal and Newborn Growth Consortium for the 21st Century definition, the prevalence of microcephaly (>2 SDs below the mean for gestational age and sex) was higher in SL (3.5%) than in RP (2.5%). The prevalence of severe microcephaly (>3 SDs below the mean) was higher in SL (0.7%) than in RP (0.5%). Low maternal schooling, living in consensual union or without a companion, maternal smoking during pregnancy, primiparity, vaginal delivery, and intrauterine growth restriction were consistently associated with microcephaly. The number of cases of microcephaly is grossly underestimated, with an underreporting rate of ∼90%. CONCLUSIONS: The prevalence of severe microcephaly was much higher than expected in both cities. Our findings suggest that microcephaly was endemic in both municipalities before the circulation of the Zika virus.
Authors: Amanda Costa Ayres Salmeron; Wallace Pitanga Bezerra; Rafaela Lúcia Lopes de Souza; Luanderson Cardoso Pereira; Lícia Maria do Nascimento; Anna Cláudia Calvielli Castelo Branco; Luiza Emilia Cavalcanti Simas; Valéria Azevedo de Almeida; Pedro Henrique de Souza Palmeira; Christiane Medeiros Bezerra; Paulo Marcos Matta Guedes; Maria Notomi Sato; Valéria Soraya de Farias Sales; Reginaldo Antônio de Oliveira Freitas Júnior; Tatjana de Souza Lima Keesen; Manuela Sales Lima Nascimento Journal: Med Microbiol Immunol Date: 2022-07-20 Impact factor: 4.148
Authors: Emily W Harville; Pierre M Buekens; Maria Luisa Cafferata; Suzanne Gilboa; Giselle Tomasso; Van Tong Journal: Arch Dis Child Date: 2019-12-13 Impact factor: 3.791
Authors: Oliver J Brady; Aaron Osgood-Zimmerman; Nicholas J Kassebaum; Sarah E Ray; Valdelaine E M de Araújo; Aglaêr A da Nóbrega; Livia C V Frutuoso; Roberto C R Lecca; Antony Stevens; Bruno Zoca de Oliveira; José M de Lima; Isaac I Bogoch; Philippe Mayaud; Thomas Jaenisch; Ali H Mokdad; Christopher J L Murray; Simon I Hay; Robert C Reiner; Fatima Marinho Journal: PLoS Med Date: 2019-03-05 Impact factor: 11.069
Authors: Hannah J Cooper; Martha Iwamoto; Maura Lash; Erin E Conners; Marc Paladini; Sally Slavinski; Anne D Fine; Joseph Kennedy; Dominique Heinke; Andrea Ciaranello; George R Seage; Ellen H Lee Journal: Obstet Gynecol Date: 2019-12 Impact factor: 7.661