During which months of pregnancy does the fetus require significant nourishment from the placenta?

The correct answer indicates that significant nourishment from the placenta is especially critical during the 4-6 month period of pregnancy. During this trimester, the fetus experiences rapid growth and development, and the placenta becomes the primary source of nutrients and oxygen necessary for fetal health.

From the fourth month onward, the placenta has matured and is able to efficiently transport vital nutrients such as proteins, carbohydrates, vitamins, and minerals from the mother's bloodstream to the developing fetus. This period is crucial as the fetus is growing and its organs are developing further, requiring substantial energy and resources.

Additionally, during the first trimester (the initial three months), while the fetus does begin relying on the placenta for nourishment, it is still largely dependent on the yolk sac for early nutrition before the placenta fully forms. The seventh to ninth months focus more on growth and fat accumulation, but the crucial periods for nutrient transfer mainly peak around the 4-6 month mark.