The word "labor" refers to the work or effort that someone puts in to accomplish a task or job. It can also refer to the group of people who work, collectively, to produce goods and services. Full definition
I feel very old school but at the same time a lot of labor of love goes into the ice cream this way. (jessicainthekitchen.com)
Slow down Toward the end of your pregnancy, slow down and save up your energy for labor day (and beyond). (babycenter.com)
Some couples find it feels better to rock and sway in rhythm to her breathing - obviously not in labor in this picture - it's the closest I could find in my images! (sweetpeabirths.com)