IAN HOOTON / SCIENCE PHOTO LIBRARY IAN HOOTON / SCIENCE PHOTO LIBRARY
Gestation calculator. This is a device for accurately detemining the expected date of delivery for pregnant women. Gestation is the period from conception to birth and lasts about 270 days (9 months). However, because of the difficulty in determining the precise date of conception it is usually timed as 40 weeks from the first day of the last menstrual period.
Model release available. Property release not required.