At 12 weeks of pregnancy, a fetus's heart is approximately 8 mm in size.
While the heart begins to develop very early in pregnancy, it's important to note that its size and development stage vary depending on the gestational age of the fetus. Here’s a breakdown:
- Early Development: The fetal heart begins to form very early in pregnancy, often before many women even realize they are pregnant.
- 12 Weeks: By the 12th week, the heart is usually in its correct position in the chest cavity (thorax), and the valves have developed enough to resemble a miniature adult heart. At this stage, it measures around 8 mm.
- Continued Growth: After 12 weeks, the heart continues to grow and develop throughout the remainder of the pregnancy.
Therefore, when asking "how big is a fetus heart?", it is essential to consider the age of the fetus. The 8mm measurement is accurate for a fetus around 12 weeks of gestation.
