While in the womb when do develop eyelashes What week pregnancy?

The development of eyelashes in a fetus occurs during the second trimester of pregnancy, typically between weeks 16 and 20. During this period, the eyelids begin to form and fuse, and the hair follicles for the eyelashes start to develop. The eyelashes continue to grow and mature throughout the third trimester, becoming longer and thicker. By the time of birth, the eyelashes are usually well-developed and can be clearly seen.