•Bartholomew's rule of fourths is a method used to determine the estimated age of gestation of pregnancy in relation to the fundal height. In this method all you need to do is to remember 3 landmarks: the symphisis pubis, the umbilicus and the xiphoid process.
•When the fundus is at the level of:
Symphisis pubis - 12 weeks
Midway between symphysis pubis and umbilicus - 16 weeks
Umbilicus - 20 weeks
Xiphoid process - 36 weeks-38 weeks