Researchers slowly honing in on risk of Zika birth defect

NEW YORK (AP) - As the international epidemic of Zika virus disease has unfolded and led to devastating birth defects for at least 1,300 children in eight countries, an agonizing question has persisted: What is the chance that an infected pregnant woman will have a baby with these defects?

Researchers don't yet have a complete answer, but they are slowly honing in on one.

Researchers slowly honing in on risk of Zika birth defect