Pregnancy week by week: how the baby develops

To count the days and months of pregnancy, it must be taken into account that the first day of pregnancy is the first day of the woman's last menstruation, and although the woman is not yet pregnant on that day, this is the date that consider why it is very difficult to know exactly when the woman ovulated and when the conception happened.

Full gestation lasts an average of 9 months, and although it can reach up to 42 weeks of gestation, doctors can induce labor if labor does not start spontaneously by 41 weeks and 3 days. In addition, the doctor may choose to schedule the cesarean section after 39 weeks of gestation, especially in situations of risk for the mother and baby.

1 month - Up to 4 and a half weeks of gestation

At this stage, the woman probably still does not know that she is pregnant, but the fertilized egg has already implanted in the uterus and what maintains the pregnancy is the presence of the corpus luteum. See what are the first 10 symptoms of pregnancy.

Changes in the body at 4 weeks of gestation

2 months - Between 4 weeks and a half to 9 weeks

At 2 months of pregnancy the baby already weighs 2 to 8 g. The baby's heart begins to beat at approximately 6 weeks of gestation and, although it is still similar to a bean, it is at this stage that most women discover they are pregnant.

Symptoms such as malaise and morning sickness are typical of this phase and usually last until the end of the 3rd month of pregnancy, being caused by hormonal changes and some tips to improve these symptoms may be to avoid intense aromas and foods, not fasting and resting for a long time, as tiredness tends to increase nausea. Check out some home remedies for seasickness in pregnancy.

3 months - Between 10 and 13 and a half weeks

At 3 months of pregnancy the embryo measures almost 10 cm, weighs between 40 and 45 g, and ears, nose, bones and joints begin to form, and the kidneys start to produce urine. At the end of this phase, the risk of miscarriage decreases, as does nausea. The belly starts to appear and the breasts become more and more bulky, which increases the risk of getting stretch marks. Learn more about how to avoid stretch marks during pregnancy.

Changes in the body at 11 weeks of gestation

4 months - Between 13 and a half weeks and 18 weeks

At 4 months of pregnancy the baby measures about 15 cm and weighs about 240 g. He starts to swallow the amniotic fluid, which helps to develop the alveoli of the lungs, already sucks his finger and the fingerprints are already formed. The baby's skin is thin and covered by the lanugo and, although the eyelids are closed, the baby can already notice the difference between light and dark.

Morphological ultrasound will be able to show the baby to the parents, but the sex of the baby is not yet to be revealed. However, there is a type of blood test, fetal sexing, which is able to identify the baby's sex after 8 weeks of pregnancy. See more how fetal sexing is done.

5 months - Between 19 and 22 weeks of gestation

At 5 months of pregnancy the baby measures about 30 cm and weighs about 600 g. The arms and legs become more proportional to the body and it looks more and more like a newborn baby. He begins to hear the sounds and particularly the mother's voice and heartbeat. Nails, teeth and eyebrows begin to form. The pregnant woman may have a darker line from the navel to the genital area and training contractions may appear.

6 months - Between 23 and 27 weeks

At 6 months of pregnancy the baby measures between 30 and 35 cm and weighs between 1000 and 1200 g. He starts to open his eyes, already has a sleep routine and has a more developed palate. Hearing is more and more accurate and the baby can already perceive external stimuli, responding to touch or being scared by loud noises. The pregnant woman will be able to notice the baby's movements more easily and so caressing the belly and talking to him can calm him down. Check out some ways to stimulate the baby still in the belly.

Changes in the body at 25 weeks of gestation

7 months - Between 28 and 31 weeks

At 7 months the baby measures about 40 cm and weighs about 1700 g. Your head is bigger and your brain is developing and expanding, so your baby's nutritional needs are getting bigger and bigger. The baby moves more vividly and the heartbeat can already be heard with a stethoscope.

At this stage, parents should start buying the necessary items for the baby, such as clothes and crib, and prepare the suitcase to take to the maternity ward. Find out more what the mother should take to the hospital.

8 months - Between 32 and 36 weeks

At 8 months of pregnancy the baby measures about 45 to 47 cm and weighs about 2500 g. The head starts to move from side to side, the lungs and digestive system are already properly formed, the bones become stronger and stronger, but at this moment there is less space to move.

For the pregnant woman, this phase can be uncomfortable because the legs become more swollen and varicose veins may appear or worsen, so walking 20 minutes in the morning and keeping more at rest during the day can help. See more how to relieve discomfort in late pregnancy.

9 months - Between 37 and 42 weeks

At 9 months of pregnancy the baby measures about 50 cm and weighs between 3000 to 3500 g. Regarding development, the baby is fully formed and is only gaining weight. In these weeks the baby must be born, but he can wait until 41 weeks and 3 days to come into the world. If contractions do not start spontaneously by this time, the doctor will probably have to induce labor, with synthetic oxytocin in the hospital. Learn more about recognizing signs of labor.

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?