Twin Pregnancy Week 12: Symptoms, Baby Size, Body Changes & More

12 Weeks Pregnant with Twins or Multiples

Medically Reviewed By
Dr. Sabiha Anjum (Gynecologist/Obstetrician)
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Congratulations on making it this far in your pregnancy journey, especially when you’re 12 weeks pregnant with twins! You’ve carried your precious bundles of joy in your womb in the safest and most nurturing way possible. These 12 weeks have been a significant part of your motherhood adventure. The first trimester is indeed crucial, marking essential phases of fetal development. The good news is that you’ve crossed the period of heightened risk in your pregnancy, and now you can shift your focus toward ensuring the well-being of both you and your precious babies as you move forward in this remarkable journey. Read on to know more about when you’re twelve weeks pregnant with twins!

The Growth of the Babies at 12 Weeks

Your babies will resemble little plums by the 12th week, and they went through an intensive growth phase in the past couple of weeks. Their size grows to nearly twice within that period.

Most of the internal organs that are present within a human body are usually developed inside the babies by the 12th week of pregnancy. By that definition, your little ones can be termed as complete human beings in a way. What remains for them is to expand in size and maintain the same pace of growth for their organs as well.

Digestion is not a process that babies need to worry about while they are inside the womb since they get all the nutrients and oxygen in a manner which can be synthesised directly. However, the stomach muscles and the intestines that have been newly formed begin to undergo certain movements, as if trying to check whether their functioning is appropriate.

The presence of bones and cartilage not only gives your children a good structure for their bodies but also sets into motion the development and formation of white blood corpuscles. This is the exact point where the immune system of your twins or multiples begins to strengthen itself.

With most of the organs developed by this time, the neural network of your twins at 12 weeks also reaches a milestone where it can sense outer stimuli and respond to them with a series of reflexive actions. Poking your stomach or changing your orientation can cause your babies to react; however, you may not be able to sense it at this stage.

What Is the Size of the Babies?

By 12 weeks, most babies are usually as large as a lime. Twins and multiples might be a bit smaller than that because of less space in the mother’s womb, but don’t worry, they will catch up soon. Your little ones would also be as long as 6-7 centimetres in length.

What is the Size of the Babies in 12th week of pregnancy

Common Bodily Changes

The changes that occur in a pregnant woman’s body at 12 weeks are not as drastic as some of the changes that have taken place in the previous weeks. A few areas that might undergo a few improvements or further changes are

  • One of the biggest changes that will take place inside you will be the size of your uterus. It will become larger in size in comparison to the previous week. This change in size makes itself apparent in a slight bulge over the stomach. Usually, this is where your babies would have their heads situated.
  • The increased diet and weight gain in babies will result in your waistline increasing by a good amount. Opting for loose-fitting clothes will soon become your preferred choice in the coming weeks.
  • Acidity and heartburn may also significantly increase given that the levels of progesterone will be receiving quite a boost this week as a result of the growing placenta. This hormone has the side effect of disturbing the proper functioning of a valve that keeps the stomach separated from the oesophagus during digestion. The acid present in the stomach can creep its way out of the valve and cause the feeling of heartburn in a woman.

A pregnant woman feels acidic

  • While the boosted blood circulation and the elevated hormones could lend a pregnancy glow to most women, there is also a chance that your skin may worsen with numerous spots, moles, and dark areas. Most of them occur around the chin and temples, which usually go away pretty soon.
  • The darkness of the nipple and areolas becomes more evident. Similarly, the tiny bumps that are present on the breast will get a more noticeable structure. All of these are evolutionary means of assisting your babies in finding your breast even with poor eyesight during their infancy.

Symptoms of Twin Pregnancy at 12 Weeks

The signs of twin pregnancy at 12 weeks will be substantially reduced as compared to symptoms in the previous months. Some other symptoms might introduce themselves, which may not always be better than before. Here are the 12 weeks pregnant with twins’ symptoms.

  • Most women notice that their vaginal discharge increases when they become pregnant, and this will increase even more in the coming weeks as well. The thick white discharge is a natural secretion from the vagina to keep itself healthy and maintain a proper pH balance. Any foul smell accompanied by a weirdly coloured discharge should be examined by a doctor immediately.
  • Just like the discharge, women tend to notice a few traces or spots of blood from the vagina, though they will be quite small. Most spotting occurs only after sex, which is quite natural. If the bleeding is heavy or if spotting occurs regularly, a doctor’s intervention is highly suggested. Spotting may also be a sign that the placenta has formed and is low-lying, so getting yourself checked by a doctor is important.
  • You might be taking good care of yourself, but even the slightest slip-ups can have serious consequences for a pregnant woman. One of the worst ones, in this regard, is recurring headaches. Anything from insufficient sleep to lack of water consumption can trigger these to take place. Make sure you are well-rested and hydrated throughout your pregnancy.
  • The blood volume increases a lot through pregnancy. This needs to be compensated with enough blood sugar along with proper fluids in the body. Any deficiency on this part can lead to a woman feeling dizzy and having low blood pressure.
  • At 12 weeks of twin pregnancy, you may notice that your breasts have become larger and more tender. This is due to hormonal changes and increased blood flow to the breasts in preparation for breastfeeding.
  • Twin pregnancies can put additional pressure on the bladder, causing more frequent trips to the bathroom. You may find yourself needing to urinate more often than usual, especially during the night.
  • Some women experience gastrointestinal symptoms such as indigestion, bloating, and constipation during the 12th week of a twin pregnancy. The growing uterus can put pressure on the digestive organs, leading to these discomforts.
  • Many women report an increase in appetite and specific food cravings during twin pregnancies. Your body may require more nutrients to support the development of two babies, leading to a heightened desire for certain foods.

Twin Pregnancy – Belly at 12 Weeks

Usually, a woman’s 12 weeks twins belly starts becoming visible by this time, but some women may not have a large belly, and hence they might be able to fit in their old clothes without difficulty. Though the size of the belly is a strong indicator of the progress of the pregnancy, there’s no absolute in that regard as long as the babies are growing properly.

Apart from the belly, there is a lot of expansion in other areas of the body as well, which will make wearing old clothes uncomfortable. The thighs and hips increase in size, making it necessary to opt for loose pants or trousers. Similarly, swelling and expansion of the breasts can necessitate getting a bigger bra.

Twin Pregnancy at 12 Weeks – Ultrasound

When you observe your little ones in the womb through an ultrasound at 12 weeks, you will see that the internal organs of your babies will have developed completely at this stage.

Through an identical twins ultrasound at 12 weeks, you will also find that your babies have started looking more like human beings instead of the vague shapes you saw in your last ultrasound. A lot of movement can be observed during the scan, which involves your babies experimenting with their arms and legs, as well as stretching their bodies to test their muscles.

What to Eat?

Just because the internal organs of your little babies have developed fully, does not mean that you skimp on any kind of food items you don’t like. A balanced diet during pregnancy is of utmost importance, and you should never compromise on it, no matter which stage of pregnancy you are at. Keep in mind that your twins or multiples are still growing, and therefore, you should eat healthy foods. Eating foods such as meat, milk products, and vegetables is highly recommended. Also, instead of eating fried or canned foods, opt for baked or boiled foods.

Make sure that you consume foods rich in fibre regularly, even in your breakfast. Keep dinners a light affair since a heavy one can make heartburn worse when you go to sleep. Restrict yourself to small and frequent meals throughout the day. Balancing your food with vitamin supplements is a good choice as well.

A pregnant woman drinks milk

Pregnancy Care Tips

Most of the symptoms that plagued you in the previous months would be on their way out. This would leave you with a better sense of being, which can be further taken care of with some useful tips.


  • Maintain vaginal hygiene by using multiple panties if you experience more discharge than usual. Also, keep your vagina clean and dry.
  • Your sex drive will return around this time, so you can indulge in sex. However, make sure you have safe sex.


  • Don’t compromise on your fluid intake. Lack of water or imbalance of fluids can easily trigger headaches and spells of dizziness, so make sure you drink enough water.
  • Don’t exhaust yourself by doing household activities and exercises the moment you have your energy back. You still need proper rest.

What You Need to Shop For?

Maternity dresses are not simply meant for formal occasions. You can get some great nightwear as well, that is comfortable and pretty. Keep track of your nutritional intake with a mobile app and replenish any deficiencies right away.

At 12 weeks pregnant with twins, know for a fact that you have crossed an important milestone of your pregnancy. Go ahead and celebrate this moment. Things will get better from here on out. Take good care of yourself, maintain an atmosphere of happiness and joy, and your pregnancy journey will turn out way better than you expected it to be.


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2. Twin pregnancy: What twins or multiples mean for mom; Mayo Clinic;

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4. How Your Fetus Grows During Pregnancy FAQs; The American College of Obstetricians and Gynecologists;

5. 12 Weeks Pregnant; American Pregnancy Association;

6. Vaginal discharge; Mayo Clinic;

7. Wierzejska. R; Review of Dietary Recommendations for Twin Pregnancy: Does Nutrition Science Keep Up with the Growing Incidence of Multiple Gestations?; National Library of Medicine;; March 2022

8. Dotters-Katz. S, Patel. E, Grotegut. C, Heine. R; Acute Infectious Morbidity in Multiple Gestation; National Library of Medicine;; January 2015

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