12th Week Pregnancy: Symptoms, Baby Development And Body Changes

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You’re 12 weeks pregnant, which means you are soon going to complete your first trimester!

Did you know that by 12 weeks, your little one’s organs are almost formed? The 12th-week is also when you notice the baby’s subtle movements for the first time through an ultrasound.

Keen to know more about what is happening within your body and how your baby is developing this week? Read this MomJunction post for more information about the 12th week of pregnancy, the baby’s development and changes in your body, plus tips that you may follow to stay healthy.

Baby Development

At 12 weeks, your baby would be about the size of a lime. This is the time when your baby starts to develop rapidly.

  1. Size: The fetus will be around 2 ½ inches in size, and 0.5-1oz in weight. Most of the features are formed by now (1) (2) (3):
  • The major external features of the body are developed.
  • Hair starts to grow, but can’t be seen till the end of the pregnancy
  • Eyelids are fused
  • Fingers and toes are developed while the nails are still developing
  • Muscles are in the developmental stage
  • External genitals are developed
  • The larynx or the voice box starts to develop in the trachea
  • Moves slightly and randomly, but the mother cannot feel the movements yet
  1. Heartbeat: This is the usual time when a doctor detects fetal heartbeat electronically. At 12 weeks, normal fetal heart rate ranges from 110 to 160, which is twice the heart rate of the mother (4). The ultrasound scan at this time of pregnancy will give you its details.

In case the heartbeat is not detected, you don’t have to worry as you might be a week or two early. Or the baby’s position might be wrong. Your doctor would try to detect the heartbeat in the coming weeks.

  1. Digestive system: The digestive system of the baby is at a developing stage at 12 weeks, and does not perform any major functions. The baby gets all the nutrition from the mother via the umbilical cord and the placenta. Therefore, you should take on a well-balanced diet.

Continue reading to know about the bodily changes you may experience in the 12th week of pregnancy.

[ Read: 13th Week Pregnancy ]

Body Changes At 12 Weeks

Changes that you may start noticing at this time include:

  1. A growing belly: You will start showing your baby bump. You may notice a round belly with a smooth waistline. However, for some women, it may begin to appear in and around the 13th or 14th week too.
  1. Change in skin tone: Some women may notice a glow on their face as they reach the 12th week, while some women find their complexion getting darker.

In addition to these, you will experience the typical symptoms of pregnancy this week.

What Are The Symptoms At 12 Weeks Pregnancy?

You might have experienced a number of pregnancy symptoms through your first trimester. In the 12th week, you may or may not have them. Some common symptoms of pregnancy in the 12th week include:

  1. Dizziness and headache: Most women experience occasional headaches during the end of the first trimester or the 12th week of pregnancy. It could be due to the straining of the eyes or stress. Sometimes, the headaches may cause dizziness as well (5).
  1. Fatigue: Morning sickness may disappear slowly by this time of pregnancy. And you may experience tiredness quite often from this week on. It could be due to the stress and the growing physical demands of the body (3).
  1. Gas and bloating: The digestive system may get slower during this time, as the uterus is growing. This results in gas formation in the stomach, making you feel bloated.
  1. Spotting: Light vaginal bleeding or spotting could happen during the first trimester, usually for not more than a day. In case you notice regular spotting, you should let your doctor know about it (6).
  1. Increased sense of smell: Many women also experience a heightened sense of smell when they reach the end of their first trimester. That’s one of the reasons why you feel an aversion to certain foods (7).
  1. Others: Excessive saliva, increased urination, or mood swings are some other changes that you could observe when you are 12-weeks pregnant.

As these symptoms are common and manageable, there is no need to worry about them. Also, they tend to fade away with time.

In the next section, we talk about the 12-week ultrasound scan and what it shows.

[ Read: 14th Week Pregnancy ]

12 Weeks Pregnant Ultrasound

The first ultrasound scan is usually done at 12 weeks of pregnancy and gives the first glimpse of the baby inside you. As most of the organs of the baby are formed by now, this scan provides details such as (8) (9):

  • Assessment of the baby’s development
  • The age of the pregnancy, and the estimated date of delivery
  • The heart rate of the baby
  • If you are carrying one baby or more. It is also possible to assess if there are any congenital abnormalities
  • Whether or not the baby is in its right place

The 12-week ultrasound takes about 20 to 30 minutes. The sonographer will apply a gel on your tummy and use a device that helps to show the black and white image of your baby on the monitor. This is a low-cost, non-invasive, and low-risk scan that gives adequate details about your baby. In case you have any doubt, feel free to ask the medical professional about it.

By the end of 12 weeks, the fetus is not as vulnerable as it has been the weeks before. But care must be taken to ensure you stay healthy, and the pregnancy progresses as it should.

Things To Remember In The 12th Week Of Pregnancy

  1. Follow a well-balanced diet as your baby is growing and would need proper nutrition.
  1. Don’t worry about the darkening of skin or stretch marks as they usually fade away with time. If not, they can be managed. You can apply sunscreen before going out in the sun.
  1. Don’t be stressed about the emotional or physical changes in your body. Instead, embrace your pregnancy and stay relaxed. Try to listen to music and surround yourself with positive people.
  1. Start exercising during this time. You can ask your doctor about the ideal exercises for this time. You can also join prenatal exercise classes that could help.
  1. Inform your doctor about any health complications such as blood pressure, diabetes, or so.
  1. Discuss prenatal vitamin intake with your doctor.
  1. You can add some maternity clothes to your wardrobe.
  1. Avoid unhealthy habits such as late night snacking, binge eating junk food, smoking, and excess consumption of sweets and fats.

[ Read: 15th Week Pregnancy ]

The completion of the 12th week marks the first milestone of your pregnancy. As each week passes, your bond with your baby will become stronger. Embrace your journey of motherhood by taking care of yourself at every step. In case of any doubts or concerns, consult your doctor.

What were your experiences during the 12th week of pregnancy? Share them with us in the comment section below.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
1. Fetal Growth And Development; SouthDakota Department of Health
2. A Woman’s Right To Know; Wisconsin Department of Health Services
3. The First Trimester; Beaumont Health
4. S. P. Steinburg et al.; What is the “normal” fetal heart rate?; Peer J Journals (2013)
5. Pregnancy – Prenatal; Cedars-Sinai
6. Vaginal Bleeding During Pregnancy Warning Signs And Causes; UNM Hospitals
7. Pregnancy by Trimester; University of California, Santa Barbara
8. Ultrasounds; The Women’s Center At Southwest Health
9. 12-week pregnancy dating scan; NHS


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Dr. Vimee Bindra

Dr. Vimee Bindra is a Consultant Gynaecologist, Laparoscopic Surgeon, and medical writer. She specializes in Gynaecology and Obstetrics, Gynae Endoscopic Surgery, and Endometriosis Excision. She graduated from R G Kar Medical College, Kolkata (1998-2003), and pursued her post-graduation in Obstetrics and Gynaecology in Kolkata (2005-2008). She also obtained the advanced Laparoscopy and Hysteroscopy training from Clermont Ferrand in France. Dr.... more

shreeja pillai

Shreeja holds a postgraduate degree in Chemistry and diploma in Drug Regulatory Affairs. Before joining MomJunction, she worked as a research analyst with a leading multinational pharmaceutical company. Her interest in the field of medical research has developed her passion for writing research-based articles. As a writer, she aims at providing informative articles on health and pharma, especially related to... more