← Chapter 9
Psychology · Chapter 9

Prenatal Development

In about 38 weeks, one fertilized cell becomes a newborn. It passes through three stages. Each stage has its own job and its own risks. Step through the stages. Then drag the week slider and pick a teratogen to see which body parts are most at risk.

The growing baby

About how long

Critical periods: drag the week

Week after conceptionWeek 5
The three prenatal stagespress Next to begin
Timing-
What happens-
Ends with-
Risk of major birth defects-
Three stagesPress Next to start with the germinal stage.

Teratogens: tap one

What is a teratogen? It is anything that crosses the placenta and harms development, causing birth defects. Examples are some drugs, infections, chemicals, and radiation. Timing, dose, and genes all shape the damage. Tap one above to shade its worst window on the chart.