Which symptom can signify that a pregnant woman is nearing labor?

The symptom that indicates a pregnant woman is nearing labor is the lightening sensation. This phenomenon occurs when the baby drops lower into the pelvis, often referred to as "dropping" or "lightening." It typically happens in the weeks leading up to labor and can make it easier for the mother to breathe since the pressure on her diaphragm is reduced. However, it may also increase pressure on the bladder, leading to more frequent urination and changes in the mother's sense of mobility.

The other symptoms listed can occur during pregnancy but do not specifically signify that labor is imminent. Decreased fetal movement might raise concerns about the baby's well-being but is not a reliable indicator of the onset of labor. Ballooning of the abdomen is generally associated with the growing size of the uterus throughout pregnancy rather than nearing labor. Increased back pain can result from various factors during pregnancy and does not definitively indicate that labor is approaching. Lightening is specifically associated with the body's preparations for labor and is a key sign that delivery may be near.