Foetal breathing movements is seen earliest at :
**Core Concept**
Foetal breathing movements are a crucial aspect of foetal development, reflecting the maturation of the central nervous system and the development of the respiratory system. These movements are a sign of lung maturation and are essential for the transition from a liquid-filled environment to a gas-filled one after birth.
**Why the Correct Answer is Right**
Foetal breathing movements are a complex process that involves the coordinated effort of various neural pathways, including the brainstem, spinal cord, and peripheral nerves. The earliest foetal breathing movements are seen around 11 weeks of gestation, when the foetal lungs start to develop and the central nervous system matures. This is also the time when the foetal lungs start to produce surfactant, a substance that reduces surface tension and facilitates lung expansion. The correct answer is **C. 11 weeks**, as this is the earliest time when foetal breathing movements are observed.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because foetal breathing movements are not seen as early as 6 weeks of gestation. At this stage, the foetal lungs are still in the process of formation and are not yet mature enough to support breathing movements.
**Option B:** This option is incorrect because foetal breathing movements are not seen as late as 20 weeks of gestation. While foetal breathing movements are still present at this stage, they are more frequent and intense than at 11 weeks.
**Option D:** This option is incorrect because foetal breathing movements are not seen at any gestational age before 11 weeks. The correct answer is **C. 11 weeks**, as this is the earliest time when foetal breathing movements are observed.
**Clinical Pearl / High-Yield Fact**
Foetal breathing movements can be an important indicator of foetal well-being and lung maturity. A lack of foetal breathing movements can be a sign of foetal distress or lung immaturity, while an increase in frequency and intensity of foetal breathing movements can be a sign of foetal stress or respiratory distress.
**Correct Answer:** C. 11 weeks