Zika, pregnancy and microcephaly
It is called microcephaly when a baby's head is smaller than the expected for that age or developmental stage (11). The identification of the problem is done by measuring the head circumference (circumference of the baby's head) and then comparing it with the reference values for each age and sex (11,12). This measure is important and should be followed up to two years of age (13).
Several situations may cause microcephaly, manifested before or shortly after birth: Down syndrome, congenital rubella, exposure to drugs, alcohol or other toxins in or out of the uterus etc. (13,14). The association of microcephaly with zika infection during pregnancy was first identified in the world by Brazilian scientists (15). Later, the Ministry of Health confirmed the relationship between the two and initiated a campaign of attention and mandatory notification of cases of microcephaly in Brazil (16).
The occurrence of microcephaly alone does not mean that the child will have motor or mental changes. In some cases, the baby develops normally. However, in the majority of cases, the child presents mild or severe cognitive alterations, according to the degree of brain involvement (17). In order to try to minimize them, it is important to initiate developmental stimulation measures as soon as possible, according to the Ministry of Health protocol for children with microcephaly (12).
11. Brasil. Ministério da Saúde. O que é microcefalia? [Internet] Disponível em: http://portalsaude.saude.gov.br/index.php/links-de-interesse/1225-zika/21849-o-que-e-a-microcefalia. Acesso em: 2017 Jun 05.
12. Ministério da Saúde, Secretaria de Vigilância da Saúde. Protocolo de Vigilância e Resposta à Microcefalia Relacionada à Infecção pelo Vírus Zika. [Internet] Disponível em: http://portalarquivos.saude.gov.br/images/pdf/2015/dezembro/09/Microcefalia---Protocolo-de-vigil--ncia-e-resposta---vers--o-1----09dez2015-8h.pdf. Acesso em: 2017 Jun 05.
13. Abuelo D. Microcephaly Syndromes. Semin Pediatr Neurol. 2007 Sep;14(3):118-27.
14. Villar J, et al. International standards for newborn weight, length, and head circumference by gestational age and sex: the Newborn Cross-Sectional Study of the INTERGROWTH-21st Project. Lancet. 2014 Sep 6;384(9946):857-68.
15. Schuler-Faccini L, et al. Possible Association Between Zika Virus Infection and Microcephaly - Brazil, 2015. MMWR Morb Mortal Wkly Rep. 2016 Jan 29;65(3):59-62.
16. Brasil. Agência Saúde. Nota à Imprensa - Ministério da Saúde confirma relação entre vírus Zika e microcefalia. [Internet] Disponível em: http://portalsaude.saude.gov.br/index.php/cidadao/principal/agencia-saude/21014-ministerio-da-saude-confirma-relacao-entre-virus-zika-e-microcefalia. Acesso em: 2017 Jun 05.
17. Stoler-Poria S, et al. Developmental outcome of isolated fetal microcephaly. Ultrasound Obstet Gynecol. 2010 Aug;36(2):154-8.