Two US Women Miscarry After Zika Infection, CDC Says

— -- Two U.S. women suffered miscarriages after being infected with the Zika virus, according to officials from the Centers for Disease Control and Prevention.

The virus, which usually causes mild symptoms including fever, rash and fatigue, has already been associated with a rare birth defect in Brazil called microcephaly. The defect is characterized by an abnormally small head and brain.

Officials have also been concerned that the virus could cross the placenta, an organ that develops in a woman's uterus during pregnancy and provides oxygen and nutrients to the fetus. This development could potentially lead to miscarriages.

CDC officials confirmed to ABC News that the women who miscarried were being monitored by their doctors after they were diagnosed with the Zika virus. In total, at least three women in the U.S. have been infected with Zika after returning from abroad with the virus.

One woman in Hawaii gave birth to a child with microcephaly in January. That woman is believed to have been exposed to the Zika virus in Brazil last year. In all three cases the Zika virus was found in the placenta.

Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical School, said the possibility of the virus being associated with miscarriages has been an ongoing concern for health officials.

"There has been a concern that is it possible that this virus...could also create sufficient inflammation in the placenta such that miscarriages can occur," said Schaffner, explaining that the link was not yet definitive. "Two cases don't make the whole story but it certainly would be biologically consistent with the [fact.]"

Schaffner said researchers would likely look to see if there is more physical evidence of the virus being linked to miscarriages in countries where virus transmission is active.