The fetal period is when brain matter forms. Approximately 100 billion brain neurons gradually develop over the 280 days following fertilization.
Beginning as a single cell upon fertilization, the embryo undergoes rapid cell division over just 280 days to form all bodily organs while simultaneously producing 100 billion brain cells—a truly astonishing rate of cellular proliferation.
The fetal brain undergoes constant transformation. Below is a month-by-month breakdown of its development:
① At 1 month of pregnancy. This is a period of vigorous, repeated cell division in the fertilized egg. The brain's basic structure begins to form, though pregnancy symptoms are barely noticeable.
② At 2–3 months of pregnancy. Brain regions like the cerebrum and medulla oblongata gradually become distinct, and brain differentiation begins. At this stage, the mother may start to feel the effects of pregnancy.
③ Months 4–5: The brain develops rapidly and takes shape, though its surface has not yet formed folds.
④ Months 6–7: Brain cells differentiate progressively, surface folds begin to form, and the structure approaches that of an adult brain. This period is also the most stable phase of pregnancy.
⑤ Months 8–9:The fetal brain development is complete. The folds are largely formed, and brain cells are nearly identical to those of an adult. ⑥ At 10 months of pregnancy, or at birth. The brain weighs approximately 400 grams and contains about 100 billion nerve cells. After this point, the number of nerve cells does not increase. To transmit information, myelination begins, glial cells start to increase, and the brain gradually develops.
Friendly Reminder: Based on fetal development within the womb, systematic and scientific prenatal education starting from the fetal stage is essential. Of course, the fetal brain remains immature, particularly as the crucial myelin sheaths are not yet fully formed. Complete brain development typically extends until around age 10 post-birth. Expectant parents should be mindful of this during prenatal education and avoid rushing the process, as haste may prove counterproductive.