What happens in the fourth month of pregnancy?

The fourth month of pregnancy is a time of significant growth and development for the fetus. Here are some of the key developments that occur during this month:

1. Fetal Growth: The fetus grows rapidly during the fourth month, increasing in both size and weight. The limbs become longer and more defined, and the fingers and toes become fully formed. The eyes move closer together and the eyelids begin to open.

2. Facial Features: The facial features of the fetus become more distinct and recognizable. The nose and chin become more prominent, and the ears move to their final position on the sides of the head. The hair begins to grow on the head.

3. Movement: The fetus begins to move more actively during the fourth month. This includes kicking, stretching, and turning. The mother may start to feel these movements, known as quickening, toward the end of the month.

4. Organ Development: The organs of the fetus continue to develop rapidly. The kidneys begin to produce urine, and the liver starts to produce bile. The reproductive organs also begin to develop, with the ovaries in female fetuses and the testes in male fetuses.

5. Heartbeat: The fetal heartbeat can be heard during the fourth month of pregnancy using a Doppler ultrasound.

6. Maternal Changes: The mother's body also undergoes changes during the fourth month of pregnancy. The uterus continues to grow and expand, putting pressure on the bladder and causing more frequent urination. The breasts may start to produce colostrum, the precursor to breast milk. The skin may become darker, and the linea nigra, a dark line running from the navel to the pubic bone, may appear.

Overall, the fourth month of pregnancy is a period of rapid growth and development for the fetus, and also brings noticeable changes for the mother.