Question

According to which rule, square root of the length of the fetus in centimeters gives the approximate age of fetus in months in first five months of fetal life:

• A. Bishop scoring
• B. Rule of nines
• C. Hiss’s rule
• D. Rule of halves

Hint:

Hiss = Heels → Length → Square root → Fetal months!

Answer 1

The Correct Option is C

Hiss’s rule is used in obstetrics to estimate the age of the fetus during the first five months of pregnancy.
It states that the square root of the crown-heel length of the fetus (in centimeters) approximately equals the age of the fetus in lunar months for the first five months.
For example, if the fetus is 16 cm long, its approximate age is $\sqrt{16} = 4$ months.
Bishop scoring is unrelated — it is used to assess cervical readiness for labor.
Rule of nines is used in burn injury assessment.
Rule of halves is not related to fetal age estimation by length.
Therefore, the correct answer is Hiss’s rule.