The four-month-old fetus is 16 weeks pregnant. At this time, the fetus is about 16cm in length and weighs about 100 g, and the face has the outline and shape of a person. At this stage, amniocentesis can be performed to screen the chromosome of the fetus. The hair, eyebrows, eyelashes, nails and toenails of the four-month-old fetus began to grow, and the vocal cords and taste buds were basically formed.
At this time, the fetal head is gradually straightened, and a thin layer of fetal hair grows, and the skin color is further red. At the same time, it becomes thicker and no longer transparent, which is beneficial to protect the interior of the fetus. Fetal hair also began to grow, mandible, cheek bone and nasal bone began to form, and auricle elongated.
Basic perfection
Hearing organs such as the inner ear were basically perfect before the fourth month of pregnancy, and they began to respond to the sound stimulation outside the uterus. The fetus's hands and feet can move slightly, and fingerprints appear on her fingers. The internal organs such as spine, liver and kidney are basically formed, and the heartbeat of fetal heart is more powerful, but pregnant women can't obviously feel fetal movement at this time.
At this time, the mother's placenta function is perfect, which can supply the fetus with nutrition from the mother, and the growth speed of the fetus is accelerated. The membranes of the placenta have grown strong, and the amount of amniotic fluid has increased rapidly since this period. In the fourth month of pregnancy, the uterus of pregnant women is as big as the baby's head, and the lower abdomen begins to bulge. And it can be clearly seen that the figure of pregnant women has changed significantly.