Engagement: This term in obstetrics refers to the sensation that a pregnant woman feels when the baby drops. This is the time when the presenting (the lowermost) part of the fetus descends and is engaged in the mother's pelvis.

Engagement is also called "lightening" because the pregnant woman feels lighter after this event.

Engagement (lightening) classically takes place 2 to 3 weeks before labor begins. However, it may not occur until labor starts, particularly in women who have already had two or more babies.