Fun and Fascinating Facts About Reproduction

A sperm’s tail beats about 20 times per second.
The largest human cell is the egg — the smallest is the sperm.
Pregnancy can temporarily change a mother’s brain structure.
The uterus can contract strong enough to lift 30 pounds.
A newborn’s first cry helps expand its lungs fully.
Twins can have different fathers — it’s rare but possible.
The placenta is the only organ grown for a temporary purpose.
Human embryos start developing before a woman even knows she’s pregnant.
Ovulation can cause a temporary rise in body temperature.
Every birth is the result of billions of perfectly timed biological events.