Just 22 days after conception a human embryo’s heart begins beating. The little heart will beat nearly 54 million times before he or she is born!

By 6 weeks plus 2 days after conception the brain waves of an unborn child can be recorded by EEG (electroencephalogram).

At just 10 weeks after conception nails and fingerprints begin to emerge in patterns that will uniquely identify a child throughout his or her entire life.

At 9 weeks after conception unborn children begin thumb-sucking. Between 12 and 16 weeks they often touch their mouths, up to 50 times an hour. Teeth start to grow by 13 weeks. Beginning at 14 weeks developmental differences between boys and girls begin to appear: female fetuses move their mouths much more frequently than males.

--The Endowment for Human Development, www.ehd.org