Terrifying. Doing some quick back of the envelope calculations: 1,000,000 people in Brazil got the virus, and there are 4,000 cases of microcephaly. Let&#x27;s assume that most of these are caused by the virus (pre-virus level of microcephaly were very low) and assume half of the people are women. Also assume roughly two pregnancies over a women&#x27;s life, and an average life expectancy of 73 years.<p>This would mean that of the 500,000 women that got the virus, roughly 2% of these women were pregnant while getting the virus, which equates to 10,000 women, resulting in 4,000 cases of microcephaly. This would be a 40% chance of microcephaly when a woman catches the virus during pregnancy. That is absurdly high for a virus that is starting to become (or already is) an epidemic.<p>There&#x27;s many assumptions in the calculation and I&#x27;m sure the medical profession has much better numbers. As I said it&#x27;s a back of the envelope. But even if the chances are 20% or 10%, that is still extremely high and worrying. The recommendation not to get pregnant in countries where the virus is active suddenly makes sense.