Pregnancy Week 12: Signs And Symptoms
Even though morning sickness and nausea may be out of the way (hopefully), you may start feeling the symptoms of heartburn, a burning sensation in your chest area (also known as acid indigestion). The placenta produces high levels of the hormone progesterone during pregnancy, which loosens the valve separating the stomach and esophagus (tube that carries food, liquids and saliva from your mouth to the stomach). The painful burning feeling is caused by gastric acid seeping back up the pipe. This happens especially when you are lying down.
Heartburn may only begin later on in your pregancy as your growing uterus pushes up against your stomach. It should be noted that the discomfort may get worse as your pregnancy goes on, so consult your doctor if it is especially painful.