The number of missing cases of microcephaly epidemic in several countries raises serious questions about the assumed connection between Zika and microcephaly, finds a new study. The epidemic of microcephaly - a birth defect where a baby's head is smaller - in Brazil has raised serious questions about its assumed connection with Zika virus. In Brazil, the microcephaly rate soared with more than 1,500 confirmed cases. A new study in Colombia found that the total number of pregnancies with Zika infections is much larger, with 11,944 cases with Zika symptoms being observed in clinical settings. But, no cases of microcephaly occurred in all of these pregnancies. However, the report cites four cases of microcephaly with Zika in the general population that did not report any Zika symptoms.