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Biology 2nd Baccalaureate

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Dilation phase

The walls of the uterus begins to contract rhythmically, so that the fetus is pushed outward, and the neck of the uterus is dilated. When very dilated breaks the amniotic sac and is released amniotic fluid, become known as "water breaks". It usually lasts 3 to 14 hours, although it is longer in new mothers.

Expulsion phase

When the contractions of the uterus are more intense and frequent, the fetus is expelled to the outside through the vagina. The cervix reaches maximum dilation.

The head pops out first, and then the contractions pull the rest of the body out. The mother also helps the expulsion by contracting the diaphragm.

Once out of the mother, the umbilical cord is cut, which dries up and falls off a few days later, leaving the navel as a scar. The baby is already an independent being.

This expulsion phase usually lasts between 15 and 30 minutes.

Birthing phase

A few minutes after the expulsion of the fetus, the uterus again has contractions so that the placenta and other remains of the pregnancy are delivered. This process is known as childbirth.

It occurs between 15 and 60 minutes after the expulsion of the fetus.

A few days after delivery, the mammary glands begin to produce colostrum, a fluid with many nutrients and antibodies. Later, it will begin to secrete milk that will be the food that the newborn baby will nourish on.


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