Women's Healthcare Topics

12 Weeks Pregnant

Reviewed by James Brann, M.D.
Learn about your symptoms and changes during the 12th week of pregnancy.

For weeks, you've probably been asking, "When will I start to show in pregnancy?" You don't have to ask this question anymore. For most women, they are finally showing. You might not have a prominent bump yet, but you should be noticing a difference in your abdomen.

But if you're 12 weeks pregnant with twins, you probably have a nice sized bump by now. Pregnant women carrying twins or multiples often look further along, compared to expectant mothers with a single baby. You may also have a larger bump if you're been pregnant before.

Your pregnancy weight gain at 12 weeks pregnant may be as high as four or five pounds. (Keep in mind that if you’ve gained more than this, that’s perfectly fine too! There is a lot of variability for different women.) If you’re carrying twins, you may have gained up to 10 pounds. Don’t be too alarmed by this early weight gain. Doctors recommend that pregnant women carrying twins gain between 35 to 45 pounds during pregnancy. For triplets, you should gain between 50 to 60 pounds.

Your morning sickness and fatigue should be decreasing now. You’ll soon start to feel much better in the second trimester, because your hormone levels tend to level off. Now as your uterus shifts upward and out of your pelvis, it may take pressure off your bladder so you won’t have as many bathroom runs. This may be a relief for you, but keep in mind that this is only a temporary break. In the third trimester, as your baby gets larger, your uterus will start pressing on your bladder again.

Your miscarriage risk is also lower now. A majority of miscarriages occur before week 12. This is a wonderful week to announce the big news to your family and friends. Enjoy this wonderful week and your diminished first trimester pregnancy symptoms!

At 12 weeks pregnant many of your uncomfortable first trimester symptoms – such as morning sickness (nausea and vomiting) and fatigue – are almost gone, or at least not as severe. You might also notice that you don't have to go to the bathroom as often.

As first trimester symptoms are starting to disappear, new symptoms will start to crop up, such as the common skin changes associated with pregnancy.

Have you ever heard the saying that pregnant women have a special “glow” about them? In some women, the increased blood flow and the increased levels of estrogen give them a beautiful, rosy complexion, or apregnancy glow.”

Unfortunately, your skin can also change for the worse during pregnancy. You may have already noticed that freckles, moles, and other dark spots on your face have become more pronounced and even darker. Some of this skin darkening will gradually fade after you deliver your baby, however these spots may remain darker than they were before your pregnancy.

You may have noticed discolored, brownish marks or patches on your forehead, temples, cheeks, and chin. This is called the mask of pregnancy” or chloasma, and it is very common during pregnancy. In fact, around 70 percent of all pregnant women experience these marks on their face.

Exposure to sunlight will make these patches darker. Chloasma is caused by the increased production of melanin (a skin pigment which protects your skin from ultraviolet light) in your body.

The “mask of pregnancy” is more common in the second trimester, but at pregnancy week 12, some women can also develop these brownish patches. There is nothing you can do to prevent chloasma, but limiting your exposure to the sun can help.

Have you started breaking out now? Acne is another common skin change that pregnant women experience, due to the high levels of progesterone in their body. If you experience breakouts during your regular menstrual period, you may be more prone to acne during pregnancy. However, some women’s acne may improve.

If your acne bothers you, you should cleanse your face regularly with a gentle cleanser. Don’t use acne medications without speaking to your doctor first. Certain acne medications, such as accutane, can cause very serious birth defects in your baby.

You also may have noticed that the area surrounding your areola and nipple has become darker. Urban legend suggests that this happens so that your baby has a better chance of finding your nipple when nursing. In reality, these breast changes are due to your pregnancy hormones.

Other breast changes you may notice during pregnancy are the little bumps on your nipple or areola becoming more pronounced. These bumps are called“Montgomery’s tubercles.” Almost all women have them, but they become more noticeable during pregnancy due to your increased levels of pregnancy hormones. At pregnancy week 12, as your breasts are enlarging, you may have already noticed these bumps.

Later in your pregnancy, you may also develop a dark line that runs from the top of your belly down to the bottom of your pelvis. This dark line is called the “linea nigra.” It is very common in the latter part of the second trimester, however women with darker skin may notice the linea nigra as early as 12 weeks pregnant.

The linea nigra will fade within a few weeks of delivery, but it may never go away completely.

The most troublesome skin change during pregnancy has to be the development of stretch marks. They are reddish or brownish lines that develop on your skin, as your skin expands during pregnancy. They often appear on your abdomen, breasts, and thighs.

At pregnancy week 12, it is probably too early for you to have stretch marks. They are more common in the second and third trimesters. Between 70 and 90 percent of all pregnant women develop these marks.

Researchers don’t know why some women develop stretch marks and others don’t. However, genetics may play a role.

At 12 weeks pregnant, you may have noticed that your skin is more sensitive and irritated than it was before your pregnancy. This is another very common pregnancy change. You may find that your favorite soaps or detergents cause irritation. To prevent irritation, you may want to use mild, unscented soaps.

Baby Section

12 week ultrasound image of baby.

Growth and Development of Baby

At 12 weeks pregnant, your baby is 2.2 inches long from crown to rump, or 55 mm in length. This is comparable in size to a kiwifruit! Your baby is big enough at this point to be weighed and weighs over half an ounce!

Though you won’t be able to feel your baby’s movements until the second trimester, he or she is happily swimming around in your uterus.

Your baby’s arms and legs are now fully formed, so your little boy or girl is probably trying all sorts of positions this week.

An exciting development now – your baby may be making a sucking movement with his or her mouth as early as this week. Your little one's mouth can open and close at this point in gestation, so your baby's time might be filled with sucking, yawning, and swallowing amniotic fluid.

Your baby’s head has a more rounded shape now and there are little buds inside his or her mouth that will eventually form into teeth!

Your baby's kidneys may be developed enough to start producing urine. (Believe it or not, but babies do urinate in the womb.)

Your baby's heartbeat is going strong. The average fetal heartbeat is around 167 beats per minute; this is double the speed of an adult's heart. Your little one's heart rate will slow down once you hit the second trimester.

Your little one's brain is starting to produce hormones now, and nerve cells are multiplying at a rapid rate. Brain synapses are also forming this week (synapses connect nerve cells together to pass information from nerve to nerve).

The umbilical cord is fully formed, but it will continue to get longer and longer as your pregnancy continues. The umbilical cord has an essential role in pregnancy – it supplies the baby with oxygen and nutrients.

At pregnancy week 12, you have reached a milestone in your pregnancy! This is probably the week of your second prenatal visit (the first doctor’s visit should have taken place around 8 weeks pregnant) and your first ultrasound scan. Are you excited to see your baby for the first time?

During this ultrasound scan, your baby will be measured from crown to rump (the top of your little one’s head to his or her bottom), so that the doctor can accurately date your pregnancy. You may also get to hear your baby’s heartbeat for the first time!

Video: 12 Weeks
Video: Your Pregnancy Week 12

Many new parents describe their baby’s heartbeat like the sound of galloping horses or fast beating drums. By now, your baby’s heart is beating 167 beats per minute – that’s twice as fast as your own heart rate!

You may be given a printout of your baby after the ultrasound scan. Don’t be surprised if you find yourself staring at the printout over and over again. You will be filled with love and joy at the sight of your little baby. After this prenatal visit, you may want to share the wonderful news with your family and friends (if you haven’t already!).

Pregnancy Health Section

Heartburn during Pregnancy

Heartburn is a common pregnancy symptom to expect. You may find that you are experiencing more heartburn than normal now. Heartburn is a burning sensation in the throat, chest and upper abdomen. This is a very common complaint during pregnancy at 12 weeks. It is caused by an increase in the hormone progesterone during pregnancy. Progesterone relaxes the valve between your stomach and esophagus. This relaxation allows stomach acids to enter the esophagus and cause severe irritation, which gives you that burning sensation.

Some great suggestions to relieve and prevent heartburn are as follows:
  • Eat less at each meal and have six meals a day instead of three.

  • Chew your food adequately and eat slowly.

  • Drink liquids before and after your meals and not with them.

  • For heavens sake stay away from fatty and greasy foods which will only make the problem worse.

  • Stay away from fizzy drinks, citrus juices and spicy meals.

  • Do not eat before going to bed.

  • Raise the head of your bed or prop yourself up with pillows which will help minimize heartburn.

  • Consider liquid antacids… they work much better than the tablet forms.

Spotlight on Twin Pregnancy

Spotlight on Twin Pregnancy.

Many women wonder early in their pregnancy if they might be carrying twins. Your physician might start suspecting a twin pregnancy early in your pregnancy if your uterus is larger than expected. Most of the time, a uterus that is larger than normal is the result of a miscalculated due date rather than twins. However, your healthcare provider might opt to perform an ultrasound now at 12 weeks pregnant (though some perform one many weeks sooner) to determine if your date is correct or if you are carrying twins.

Some telltale signs that you might be carrying twins include: larger than average uterus for your due date, larger weight gain early in pregnancy, more than one heartbeat, worse than normal morning sickness, and increased levels of AFP.

A twin pregnancy is usually considered a higher risk pregnancy, but that doesn't necessarily mean you will have complications. One of the more common risks associated with carrying twins is pre-term labor, but many people will go on to carry their twins to term.

There is a slightly elevated chance of miscarriage in multiple pregnancies. Sometimes a mother will lose one baby but go on to carry the other to term. Most of the time however, the risk of fetal loss is reduced after the 12th week of pregnancy. Typically women who lose one twin will go on to deliver the other baby without complication. If a twin is lost in the first 12 weeks of pregnancy it will actually be reabsorbed and not cause any harm for the health of the infant that is continuing its development in your body.

If you are carrying twins or multiples, you are also at an increased risk for developing preeclampsia, a condition that results in high blood pressure during pregnancy. Preeclampsia is more common in up to 20 percent of women carrying multiples.

You may realize worse than normal pregnancy symptoms if you are carrying twins, but this isn't always the case. Horrible morning sickness can strike a mom carrying a singleton just as much as one carrying multiples. Symptoms of fatigue and general discomfort are sometimes greater in moms carrying multiples, particularly later in pregnancy or during the third trimester.

Almost half of all mothers with multiples will go into labor before 37 weeks pregnant. Many women assume that they will undergo a cesarean section if they are carrying twins, but this is not always the case. There is a good chance you will be able to deliver both of your babies vaginally, depending on the position they present in at birth, and whether or not you experience any complications such as preeclampsia during your pregnancy.

Some women will have to be put on bed rest during their pregnancy in order to help minimize complications such as pre-term labor. A woman carrying multiples will likely be encouraged to take things easy much earlier than a woman carrying one baby.

If you are carrying multiples, even during pregnancy week 12, it is very important that you remain well hydrated and eat nutrient dense foods to maintain your energy levels and stay healthy during pregnancy. The average weight gain for a twin pregnancy is usually 45 pounds, which is more than the 25-35 pounds recommended for singleton mothers. (next week)