What is the term for the “lightening” that occurs before labor?

The term "lightening" refers to the process of the fetal head descending into the pelvis in preparation for labor. This occurs as the pregnancy approaches term and is characterized by the mother experiencing relief from pressure in her diaphragm, making breathing easier, while she may feel increased pressure in her bladder as the fetus moves downward. This descent of the fetus is referred to as engagement, which means that the widest part of the fetal head is entering the pelvic inlet.

The engagement of the fetus is a significant indicator that labor is approaching, as it often happens one to four weeks before labor begins, particularly for first-time mothers. This process is crucial because it positions the fetus appropriately for birth, facilitating a more efficient labor process. Understanding lightening and engagement helps healthcare providers and expectant mothers anticipate and prepare for the onset of labor.