**Question:** During active labour, cervical dilatation per hour, in primigravidae is:

A. 1 cm
B. 1 cm/hour
C. 1 cm/2 hours
D. 1 cm/3 hours

**Core Concept:**
During active labor, cervical dilatation occurs due to the interaction between the biochemical and mechanical changes within the cervix. In primigravidae (first-time pregnant women), the process is more prolonged compared to multigravidae (women with previous pregnancies), which is why understanding the cervical changes is essential.

**Why the Correct Answer is Right:**
In primigravidae, cervical dilatation is slower due to the absence of the adaptive changes seen in multigravidae. The process is more gradual and might be accompanied by increased cervical secretions (effacement) and increased station measurement. In the active phase of labor, cervical dilatation occurs at a rate of approximately 1 cm per hour, making option B the correct answer: "1 cm/hour".

**Why Each Wrong Option is Incorrect:**
A) 1 cm/2 hours: This is too slow, as cervical dilatation should progress at a more rapid rate than this during active labor.
C) 1 cm/2 hours: Similar to option A, this is too slow and does not accurately reflect the typical cervical changes during active labor.
D) 1 cm/3 hours: This rate is too slow, and cervical dilatation should occur at a more rapid rate during active labor.

**Clinical Pearl:**
Understanding the difference in cervical changes between primigravidae and multigravidae is essential for accurate assessment of labor progression and appropriate management of labor. If cervical dilatation is slower than expected, it could indicate an issue such as fetal compromise, maternal hypoxia, or cervical dystocia.

**Correct Answer:** B) 1 cm/hour