Rule of Hasse is used to determine -

RULE OF HAASE: This is a rough method of calculating the age of the fetus. The length of the fetus is measured from crown to heel in centimeter During the first 5 months of pregnancy, the square root of the length gives an approximate age of the fetus in months, eg: a fetus length is 16cm is 4 months. HAASE'S MODIFICATION OF MORRISON'S LAW: during the last 5 months, the length in centimeters divided by five gives the age of the fetus in months, eg: fetus of 35cm is 7months. REF: The Synopsis of Forensic Medicine and Toxicology by Dr. K.S.Narayan Reddy 29th edition page no: 51