21 Things You Cannot Do When You’re Pregnant Pregnancy, also known as gestation, is the time during which one or more offspring develops inside a woman. 1.Smoke marijuana. 2.Be exposed to secondhand smoke. 3.Ride a bike. 4.Drink coffee. 5.Ride a roller coaster. 6.Gain too much weight. 7.Work on your feet. 8.Move furniture. 9.Eat too much. 10.Wear high heels. 11.Take migraine medication. 12.Get a tattoo. 13.Stand on a subway 14.Drink beer. 15.Color your hair. 16.Get a piercing. 17.Have sex intensely. 18.Take sleeping pills. 19.Do yard work. 20.Spend too much time in the sun. 21.Give blood.