There actually is no evidence specifically linking Zika virus to microcephaly. There are many causes of microcephaly, including genetic, poor health of the mother, and a limited number of virus infections.
Women who are afraid of getting Zika virus during pregnancy can theoretically be tested for immunity before getting pregnant. I say theoretically, because such a test is fairly straightforward, but I do not know if the FDA has licensed such a test yet. If I were a Zika virus researcher, I’d be hustling to standardize and “idiot-proof” such a test in order to get that FDA approval. A woman who is immune can safely get pregnant without worry that she will transmit the virus to her unborn child.
I have seen pictures of people with small heads that look like the ones affected by Zika. Is there another cause of the small head syndrome or is it always and only caused by Zika?”
No, those are Democrats.
Google hydrocephalus. It has many causes.
Lots of causes. Most of the increase in Brazil is due to measurement and reporting not Zika. AFAIK, there are only 6 small head cases out of thousands where Zika was confirmed. Most of the rest were not tested. The thousands in the past were clearly not Zika and at least 75% were unreported.