The first thing I tell my patients is that the risk of someone in the United States contracting the Zika infection, which is spread by a mosquito bite and sexual intercourse, is extremely low.Since the Zika virus can be spread from mother to her fetus, the primary concern is for the health of the unborn child, specifically the risk of microcephaly. This birth defect can result in abnormality of the child’s brain and head size and shape. Neurological disorders can be serious and include seizures and slow development. According to preliminary findings from the US Zika Pregnancy Registry, only 6 percent of infants or fetuses in Zika-associated pregnancies have documented signs of Zika-related birth defects. For expectant mothers who reported Zika exposure or symptoms in the first trimester, the percentage of birth defects was slightly higher at 11 percent. In November 2016, the Journal of the American Medical Association identified a number of birth defects that are directly linked to the Zika virus that they refer to as congenital Zika syndrome. These birth defects include:
- Severe microcephaly, including a partially collapsed skull and an abnormally small sized head
- Damage to the back of the eye with increased pigment and a specific pattern of scarring
- Joints with a restricted range of motion, such as clubfoot
- Reduced brain tissue with a specific calcium deposit pattern indicating brain damage
- An abundance of muscle tone, limiting movement soon after birth.
However, not every pregnant woman infected with the Zika virus has a baby with microcephaly. The Centers for Disease Control (CDC) reports that the connection between Zika infection and microcephaly is not adequately understood at this time, and more studies and laboratory analysis are needed.