What Happens during Your Sixth Month of Pregnancy?

By (embryologist) and (fertility counselor).
Last Update: 01/14/2019

The sixth month of pregnancy comprises week 21 to 24 of pregnancy. From this moment on, fetal development is at an advanced stage, since you are now halfway through your pregnancy.

At month 6, we are almost at the end of the second trimester of pregnancy, which is commonly the most comfortable one for the pregnant woman. Both the woman and the baby, however, continue experiencing great changes, especially in the unborn baby, who is already in a fetal position in the uterus.

Symptoms to expect

All the symptoms of the previous months aggravate during the sixth month of pregnancy. The following are the most common ones:

Stretch marks
Your skin stretches in a way that is noticeable to the naked eye, which can cause itching and stretch marks.
Skin rashes
Rashes may appear due to an increased level of estrogens. These hormones activate melanocytes, the cells that produce melanin. Skin rashes typically appear in the face, and are known as melasma or chloasma.
Frequent urge to urinate
Baby movements are more noticeable than in month 5 because there is almost no room available for him to move freely. This puts pressure on the bladder, increasing the number of times the woman has to pee.
Back pain
The weight of amniotic fluid, placenta, and the fetus himself can cause backache.
Colostrum comes in
This fluid is the precursor of breast milk, produced by the mammary glands in the previous months before birth as well as during a few days after birth. Colostrum can come in any time during the day, and it is a totally normal event. You can wear a protective cover over your nipple to prevent it from staining your clothes.

These symptoms can be more or less annoying depending on each woman and the characteristics of her pregnancy. In any case, if you notice some kind of abnormal sign, we recommend that you contact your doctor as soon as possible.

Changes in the baby

Even though the size of the baby is a considerable one, there is still little room for him or her to move freely inside your womb. This is the reason why you notice vigorous movements inside you.

The most obvious changes at this point of pregnancy are a considerable weight gain as well as an increase in length. On average, when a fetus is 6 months old, the weight can be 750 g and the length as long as 35 cm approximately.

The body is more proportioned now, with a much more human-like appearance, especially the facial features, since both eyebrows and eyelids form during this month. Approximately during this month, the baby is able to open the eyes and even react to certain visual stimuli.

The skin is still thin, although it is starting to wrinkle. In spite of this, it is not totally transparent now: it has acquired a more pinkish color due to the presence of capillaries. Still, more fat layers have to form under the skin.

The ear, which started developing during month 5, finishes its formation throughout month 6. By the end of it, the baby is able to distinguish the voice of others aside from his/her mother's.

The sense of taste continues its development this month and, by the end of it, the taste buds will be fully formed, allowing the baby to differentiate between different flavors, since now he is able to drink and swallow amniotic fluid.

As for the lungs, they are still in an immature phase. In fact, given that they are not necessary until the moment of birth, they are the last organs that form. At this point, they are filled with amniotic fluid, and the pulmonary alveolus have not developed fully yet.

Sixth month of pregnancy by week

Find all the details about each one of the weeks that form the month 6 of pregnancy below:

Week 21

The baby's activity starts being frenetic in this week. In fact, according to different medical reports, the fetus can change the position up to 50 times in an hour during this stage of pregnancy. All these movements favor the baby's correct physical and mental development.

If the baby-to-be is a girl, by the end of this week her ovaries will be filled with up to 6 million follicles (structures that contain egg cells). From this moment on, this amount will diminish up to the moment of birth, when the follicle count ranges between 1 to 2 million.

Another substancial change that occurs in babies during week 21 is that the bone marrow is almost fully formed, and is now in charge of red blood cells production. Till this moment, the spleen and the liver were responsible for carrying out this function.

Week 22

At week 22, the baby already weighs about 1 kg and the presence of vernix caseosa, a fatty layer that covers his skin, is more than noticeable.

The limbic system of the baby, formed by the thalamus, the hypothalamus, and the amygdala develop during these days. This part of the nervous system is responsible for making emotions, memory and hunger possible, allowing the baby to have the first mood swings.

Assisted procreation, as any other medical treatment, requires that you rely on the professionalism of the doctors and staff of the clinic you choose. Obviously, each clinic is different. Get now your Fertility Report, which will select several clinics for you out of the pool of clinics that meet our strict quality criteria. Moreover, it will offer you a comparison between the fees and conditions each clinic offers in order for you to make a well informed choice.

Week 23

In week 23, the thin skin of the fetus, which used to be red to date, starts turning into a more pale color. The baby will be born with a mild pigmentation in the skin, but will not have its definitive color up until he or she is at least 1 year old. The iris of the eyes is not pigmented yet, so the color of his/her eyes remains unknown.

Lanugo, the thin layer of hair that covers his body, is becoming darker, covering the head as well.

As for the skeleton, its development continues: cartilage is turning to bones through a process known as calcification. The duration of this process continues for several years post birth.

The respiratory system starts rehearsing little breathing movements, although the supply of oxygen that the baby requires is provided by the mother through the umbilical cord.

Week 24

All sense organs are almost fully formed, except for the sight, which requires various months after childbirth until its complete formation. Nonetheless, they are sensitive to bright light through the mother's skin.

During week 24, the baby learns to open and shut the eyes. This movement is the precursor of the blinking reflex.

Medical visits during month 6

Normally, the second trimester ultrasound is conducted before the sixth month of pregnancy, so there is no need for the woman to go for any other image test.

Nonetheless, it actually depends on the development of each pregnancy. For instance, in cases of high-risk pregnancy, or if the mother or the fetus have some kind of problem, it is likely that a greater level of control is needed.

During month 6, pregnant women usually undergo a test called screening glucose challenge test, also called O'Sullivan test. It is typically performed from week 24 onwards and is used to detect gestational diabetes.

Gestational diabetes is a type of diabetes that appears in pregnant women.

The specific cause of gestational diabetes is still unclear, although it is believed that it is due to the huge hormonal changes that occur in women when they get pregnant, including a deficiency in the cells to collect glucose.

In most pregnant women, pancreas detects that insulin levels are insufficient for the proper collection of glucose. As a result, it produces greater amounts of insulin, thereby solving this abnormality.

However, if insulin production does not increase, glucose levels in blood won't descend, causing gestational diabetes.

This condition disappears after pregnancy in most cases, when hormone levels have returned to normality.

You might also like: What Is Gestational Diabetes? – Symptoms & Causes.

Screening glucose challenge test

This diagnostic test involves a bloodwork as the first step to measure glucose levels, and then they are written down. After that, the pregnant woman drinks a glucose solution (water with 50 g of glucose). Finally, the bloodwork is repeated within an hour, and glucose levels are measured again.

Most specialists render a diagnosis of gestational diabetes if glucose levels are above 140 mg/dl. Keeping this in mind, the potential outcomes of the test can be:

Negative result
Glucose levels in blood of both tests are below 140 mg/dl. This indicates that there exists no issue concerning glucose assimilation by the body.
Positive result
Glucose levels in any of the bloodworks is above 140 mg/dl. When this occurs, a test called oral glucose tolerance test (OGTT) is performed to render a more accurate diagnosis of gestational diabetes.
Gestational diabetes
If glucose levels are higher than 200 mg/dl, gestational diabetes is diagnosed without performing any other further test to verify the result.

Tips for the 6th month of pregnancy

Given that each pregnancy and woman are different, so are the different medical tests you will have to undergo. Nevertheless, there exist a series of common symptoms, like nausea and backache, the are commonplace in month 6 of pregnancy.

The following are a few useful tips for you to follow at this stage of your pregnancy:

  • Increase the presence of zinc in your diet
  • Try not to drink water or any other liquid right after getting up
  • Avoid very fatty foods or canned food, as well as sugary drinks
  • Try to ventilate enclosed spaces, since your sense of smell gets more sensitive during pregnancy and this could increase your nausea
  • Practice relaxation techniques and breathing exercises

Most doctors recommend that 6-month pregnant women take up antenatal classes from this month onwards. It is crucial that you start training your body for childbirth in advance.

FAQs from users

Is it normal to have contractions at 6 months?

By Victoria Moliner BSc, MSc (embryologist).

Yes, it is possible that you have a type of contractions called Braxton-Hicks contractions. In fact, some women start having them from month 5. These contractions are typically so mild that most pregnant women do not even notice them. Their function is to prepare the body for labor.

I've heard about the 4D ultrasound scan. Can you do it at 6 months?

By Victoria Moliner BSc, MSc (embryologist).

Yes. As a matter of fact, month 6 is a good moment for women to undergo this test. As explained above, the baby has a more human-like physical appearance by this time

What is the average weight gain for 6 months pregnant women?

By Victoria Moliner BSc, MSc (embryologist).

Actually, there is no average weight range for this gestational age, as each woman has a different weight based on their body complexion. Nonetheless, according to experts, most pregnant women will have gained between 6 to 8 kg by this stage of pregnancy.

This is just an approximate range. As explained earlier, each body and pregnancy is different, and so their progression.

Suggested for you

Making it to week 21 of pregnancy means going through the halfway point of it. It is a crucial stage of pregnancy, since the fetus starts developing the five senses and moving more humanly. Read this next: 21 Weeks Pregnant.

As we know, the diet to follow is a common doubt amongst pregnant women from the first month of pregnancy, as well as what activities are advisable and when should they visit their doctor. Get answers here: The Importance of Staying Healthy during Pregnancy.

Last but not least, we know that having sex during pregnancy is another controversial topic for couples during pregnancy. In general, you should know that it causes no damage at all to the baby, although you should be specially careful during the final weeks of pregnancy. This post will provide you with a much deeper insight on this: 10 Tips to Enjoy Sex During Pregnancy.

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FAQs from users: 'Is it normal to have contractions at 6 months?', 'I've heard about the 4D ultrasound scan. Can you do it at 6 months?' and 'What is the average weight gain for 6 months pregnant women?'.

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 Victoria Moliner
Victoria Moliner
BSc, MSc
Degree in Biochemistry and Biomedical Sciences from the University of Valencia (UV). Master's Degree in Biotechnology of Human Assisted Reproduction from the UV and the Valencian Infertility Institute (IVI). Presently, she works as a Research Biologist. More information about Victoria Moliner
Adapted into english by:
 Sandra Fernández
Sandra Fernández
B.A., M.A.
Fertility Counselor
Bachelor of Arts in Translation and Interpreting (English, Spanish, Catalan, German) from the University of Valencia (UV) and Heriot-Watt University, Riccarton Campus (Edinburgh, UK). Postgraduate Course in Legal Translation from the University of Valencia. Specialist in Medical Translation, with several years of experience in the field of Assisted Reproduction. More information about Sandra Fernández

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