During the fourth month of pregnancy, the fetus undergoes significant growth and development. By the end of the four-month mark, which is roughly the beginning of the second trimester, the fetus is approximately 6.7 to 7.4 centimeters (about 2.6 to 2.9 inches) in length from crown to rump. The weight of the fetus at this stage generally ranges between 20 to 30 grams (0.7 to 1 ounce).
At this point in the pregnancy, the fetus is developing rapidly. The fourth month is characterized by the maturation of vital organs and the beginning of more recognizable human features. The fetus’s arms and legs are more proportionate, and its movements become more coordinated. This is also when the facial features become more distinct, and the ears and eyes are nearing their final positions. Additionally, the fetus starts to develop a more defined body structure, including bones that are beginning to harden from cartilage.
The growth during this month is crucial for several reasons. The development of organs such as the intestines, kidneys, and liver continues, and the fetus begins to practice breathing movements. These movements are not yet functional for respiration but are essential for preparing the fetus for life outside the womb. The skin of the fetus is still translucent, but it is beginning to form a more structured layer of skin.
This stage of fetal development is also significant for the mother. By the end of the fourth month, the pregnancy is typically more visibly apparent, as the uterus expands to accommodate the growing fetus. The increase in the size of the uterus can contribute to various physical changes and symptoms, such as an expanding abdomen, and it may also alleviate some early pregnancy symptoms like nausea and fatigue.
Monitoring fetal growth is a critical aspect of prenatal care. Healthcare providers often use ultrasounds during this period to assess the fetus’s growth and development. These ultrasounds help ensure that the fetus is developing as expected and can also provide valuable information about the overall health of the pregnancy.
The fourth month of pregnancy is a time of remarkable progress for the fetus, setting the stage for continued growth and development in the coming months. The advancements made during this period lay the groundwork for the fetus’s transition to a fully developed newborn, ready for life outside the womb.