Fetuses begin moving in the womb about as early as 7 weeks, when they slowly bend their necks, according to a review paper published in the journal Ultrasound in Obstetrics & Gynecology.
Zika tends to attack neuroprogenitor cells, which are common in fetuses but rare in adults.
In one British study, the fetuses of super-stressed pregnant women were more likely to touch their faces more with their left hands than their right.
It is best not to eat more than this, as many types of fish contain traces of methylmercury - a metal believed to be harmful in high doses to the growing brains of fetuses.
