About 1 in 31 children in the US has autism. Here's what the latest data shows about diagnosis trends, gender differences, and what's behind the rising numbers.
At 34 weeks, most babies weigh around 4.7 lbs, but a healthy range varies. Learn what influences fetal weight and what small or large estimates really mean.
The AIDS epidemic has claimed tens of millions of lives since the 1980s. Here's a look at the death toll, who was most affected, and where things stand today.