Baby development

At 4 weeks of gestation, which is equivalent to the 1st month of pregnancy, three layers of cells have already formed giving rise to an elongated embryo with a size of about 2 millimeters.

The pregnancy test can now be done, because the human chorionic gonadotropin hormone is already detectable in the urine.

Embryo development

At four weeks, three layers of cells have already formed:

The outer layer, also called ectoderm, which will transform into the baby's brain, nervous system, skin, hair, nails and teeth; The middle layer or mesoderm, which will convert to the heart, blood vessels, bones, muscles and organs the inner layer or endoderm, from which the lungs, liver, bladder and digestive system will develop.

At this stage, the cells of the embryo grow lengthwise, thus acquiring a more elongated shape.

Embryo size at 4 weeks

The size of the fetus at 4 weeks of gestation is less than 2 millimeters.

Changes in women at 4 weeks of pregnancy

Generally, the most common changes in women at 4 weeks of pregnancy are tiredness, discouragement, sore breasts, irritability and the desire to cry, which is normal due to hormonal changes. If pregnancy symptoms are present and menstruation does not come, it is best to take a pregnancy test. Know how to recognize the first symptoms of pregnancy.

At this stage of pregnancy, it is very important to eat well and avoid alcoholic beverages and cigarettes, in order to reduce the risk of complications during pregnancy and for the baby to be born healthy.

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Your pregnancy by trimester

To make your life easier and you don't waste time looking, we have separated all the information you need for each trimester of pregnancy. What quarter are you in?