5 weeks of gestation: what are the changes in the mother and baby?

In the 5th week of gestation, the baby is still very small (smaller than a grain of rice), but the symptoms in most mothers have already started to appear.

At this stage, the baby’s development is very accelerated – there are more than 1 million new cells per minute! – although the pregnant woman may not even know that she is pregnant.

The heart is the first organ to develop. The baby’s heartbeat already happens, but it still doesn’t follow a rhythmic pattern, which will be better defined in the coming weeks.

The neural tube is already at the beginning of its formation. It will be transformed into the brain and spinal cord. To avoid spinal cord malformation, it is at this stage that pregnant women need to take folic acid according to the recommendation of the obstetrician.

In this text, we will explain a little more about what happens in the 5th week of pregnancy, about the ultrasound and the symptoms of the pregnant woman. Continue reading and check it out!


How many weeks of gestation is equivalent to how many months?

The 5th week of gestation marks the beginning of the second month.

From that week on, the zygote (the cell resulting from fertilization) is considered an embryo. It is a period when the growth of the fetus is very large: starting with the size of a sesame seed, it will be approximately 17cm at the end of the month.

It is also at the beginning of the second month of pregnancy that the woman usually begins to show signs of pregnancy, showing body changes and the first gestational symptoms.

Ultrasound: can you hear the heart?

In most cases, no. The baby is still tiny, and the heartbeat is neither uniform nor intense.

It is common for pregnant women to perform transvaginal ultrasound after the 5th week. In it, normally only the gestational sac is visualized, and it is not possible to identify the fetus yet.

However, this is no reason to panic! It is normal that it is not possible to hear the beats yet, as they will only be regularized at the end of the second month of pregnancy.

What changes in the body at 5 weeks pregnant?

One of the first changes in the body of the pregnant woman is the swelling in the breasts, which can become painful and sensitive. This happens by the multiplication of the mammary glands.

In addition, hormonal changes are becoming more evident. Estrogen and progesterone – the female hormones – are being produced by the woman’s body more and more.

This has as one consequence the increase in the size of the uterus, adapting to the growth of the baby. He puts pressure on his bladder and causes a constant urge to pee.

What are the symptoms at 5 weeks of gestation?

At 5 weeks of gestation, the increase in metabolism (changes necessary to meet the needs of the developing fetus) starts to cause more evident symptoms, such as drowsiness, excessive tiredness .

Hormonal changes and the discovery of pregnancy can cause psychological symptoms, such as high sensitivity and anxiety .

Other symptoms that commonly appear at 5 weeks of gestation are:


The pregnant woman may experience menstrual-like cramps, causing pain in the lower back. It is a common symptom at this early stage of pregnancy and should not be a cause for concern.

They happen due to the enlargement of the uterus and tend to decrease after the third month.


One of the most well-known symptoms of early pregnancy is feeling sick. They are more frequent in the morning, but they can also happen when the pregnant woman feels nauseous when she smells or eats some food.

Nausea is very common and usually does not pose a danger to the pregnant woman or the baby. It is a symptom that usually lasts until the end of the first trimester of pregnancy.


The headache can also appear at 5 weeks of gestation. Sickness, tiredness and hormonal changes can contribute to the onset of headache.

Normally, it poses no serious risk. However, if it comes with stomach pain and blurred vision, it may be an indication of high blood pressure . In such cases, it is essential to consult the obstetrician.

The 5th week of pregnancy is the beginning of the second month, in which the symptoms of pregnancy become more evident.

The embryo will then develop very quickly. Despite being a difficult period and that can generate anxiety, soon the pregnant woman will have calmer moments even though the changes in the organism continue to be intense.