When does a pregnancy line start showing

• If it's your first pregnancy, you'll probably start to show at 12 to 16 weeks. 
• You'll likely show early if you're short, carrying multiple babies, or you've been pregnant before.
• By week 20, your doctor will start measuring your baby bump to track fetal growth.

Pregnancy bumps are as diverse as the babies they produce. 

You start to show in pregnancy at 12 to 16 weeks 

If it's your first pregnancy, you'll probably start to show between 12 to 16 weeks, around the start of your second trimester. But this initial bump is not from the baby. In fact, at 15 weeks, the average fetus is 4 inches long, or about as large as an orange. 

So that "baby bump" isn't from the baby's size, but rather the expansion of your uterus.

"As the uterus gets bigger with a developing pregnancy, the loops of bowel which fill the abdomen are pushed upwards and out to the sides," says Meg Wilson, MBBS, an OB-GYN at London Gynaecology.

What causes some to show early in pregnancy?

There are a few factors that might affect when you start showing: 

• Height: If you have a short abdomen, your bump will likely pop out sooner than for taller women with a longer abdomen. "Women who have a long abdomen may have more space for their uterus to develop upwards rather than outwards, which can give the appearance of a smaller bump," Wilson says.  
• Weight: If you're smaller with less body fat, you'll probably show much earlier than someone with more body fat. 
• Multiple buns in the oven: If you're carrying twins or multiples, you're more likely to show earlier — as early as 6 weeks. That's because your uterus will expand more to create space for the additional fetuses. 
• Not your first rodeo: You're more likely to show early if this isn't your first pregnancy.  "The uterus is held in position at the front by the abdominal walls: skin and muscle strength," says Wilson. "For women who have had several pregnancies, the skin and muscle become weaker and the pregnant uterus can fall forward more."

How doctors track baby bump progression

By week 20, your doctor will start measuring your fundal length — that's the distance between the pubic bone and the top of the uterus. Typically, this number should correlate with your week of pregnancy.

So, for example, if your fundal length is 25 centimeters, you should be in or near your 25th week of pregnancy. 

If, however, your fundal length is too high, it could indicate growth problems with the baby, like fetal macrosomia, which is when a baby is significantly too large. 

On the flip side, if your fundal length is too low it could mean restricted growth, which is when the baby isn't large enough. While not all small babies suffer from restricted growth, it's worth checking in with your maternal health practitioner if you are concerned. 

Insider's takeaway

There are several factors that affect when your baby bump will start to show during pregnancy. 

When it's your first pregnancy, it's common for your bump to start showing between 12 and 16 weeks. The initial baby bump is caused by the expansion of the uterus, rather than the size of the fetus.

If you have a short abdomen, less body fat, are carrying multiple fetuses, or it's not your first pregnancy, then you are more likely to show early. 

Your doctor will begin measuring your fundal length by week 20. This measurement helps doctors track fetal growth.

Rebecca Cairns is a freelance writer for Insider. 

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Pregnancy can come with some unusual body changes, like hair in places you didn’t expect, sudden indigestion, hemorrhoids and acne breakouts. But here is a lesser-known surprise to add to the growing list of pregnancy pleasantries: Linea nigra. This dark line that can develop down the center of your bump may catch you off guard. So what is linea nigra, when does it appear and what can you do—if anything—to make it go away? Here’s what you need to know about the pregnancy line on your stomach.

Linea nigra, which is Latin for “black line,” is a streak running from your belly button to your pubic region that may develop and darken during pregnancy, according to the American College of Obstetricians and Gynecologists (ACOG). The length, width and color of this pregnant belly line varies from person to person.

Image: Getty Images (2)

Its appearance might make you do a double take, but it’s nothing to be concerned about. “Linea nigra is simply the increase in pigmentation of the skin,” says Julie Lamppa, APRN, a certified nurse-midwife at the Mayo Clinic and the author of Obstetricks. “Linea nigra can look slightly different on everyone,” and it may be more obvious if you have darker skin, says Christine Greves, MD, a board-certified ob-gyn at the Winnie Palmer Hospital for Women & Babies. People with darker skin have more melanocytes, which are pigment-producing cells, making them more prone to getting this line, explains Michael Cackovic, MD, a maternal-fetal medicine physician at the Ohio State University Wexner Medical Center.

It’s important to emphasize that this dark line on your stomach isn’t something that will impact you or baby. “Pregnant women can be reassured that linea nigra isn’t harmful and has no adverse effect on pregnancy outcomes or the baby,” says Jessica Shepherd, MD, an ob-gyn and founder of Sanctum Med + Wellness in Dallas, Texas. It’s just one of those things that you may (or may not) have to deal with for a while.

Does everyone get linea nigra?

While the linea nigra line is common, not every mom-to-be will get it. In fact, there’s no way to tell in advance if this is something you’ll develop during pregnancy. “We don’t know why some people get it and others don’t,” Greves says. Of course, having more pigment-producing cells may make you more prone to it, but it’s certainly not a guarantee. If you have linea nigra once, you’re probably going to have it in subsequent pregnancies too.

What Causes Linea Nigra?

Linea nigra is just one of the many skin changes that can happen during pregnancy. “Almost all pregnant women develop some type of hyperpigmentation in their skin in certain areas,” Cackovic says. For example, many pregnant women notice their areolas darkening or experience dark patches of skin that appear on the face, known as melasma. These melanocytes are likely stimulated by hormones like estrogen and progesterone, which surge in your body during pregnancy, Greves explains.

Unfortunately, there’s no definitive known way to avoid linea nigra. While you might not love the look of it, the important thing to remember is that it’s totally normal.

When Does Linea Nigra Appear?

This signature belly line can technically show up at any point in your pregnancy, but it will typically surface sometime in the second or third trimester, Lamppa says. Again, not everyone gets linea nigra. Either way, it’s no cause for stress.

What Is the Purpose of Linea Nigra?

While some physical changes that happen in pregnancy, like your breasts growing, have a biological purpose, experts say there’s no clear reason why your body would need to develop linea nigra. You can file this one under the many mysteries of pregnancy. “There’s no biological purpose for this,” Greves says.

Sorry to spoil your fun, but if you’ve heard an old wives’ tale that the length of your pregnant belly line will determine whether you’re having a boy or a girl, we’re here to debunk that myth. (It specifically claims that if the linea nigra starts below your belly button, you’re carrying a girl; if it extends above your navel, you’re supposedly having a boy.) While this is a fun guessing game to test out, Greves stresses that it’s not a legitimate way to determine baby’s sex.

When Does Linea Nigra Go Away?

If you’re wondering when the linea nigra will go away, you’ll have to be patient. There’s no clear-cut answer: The truth is, it depends. But in all likelihood, you’ll probably notice some changes in your skin soon after baby is born. “As hormonal levels start to decrease and stabilize, linea nigra should start to fade in the weeks and months after birth,” Lamppa says. Still, Cackovic adds that it can take up to a year or longer for linea nigra to fade in some people. What’s more, for others, this pregnancy line may never completely go away.

There are really no at-home remedies you can use to get rid of linea nigra during or after pregnancy. If it continues to linger after baby is born, consider seeing a dermatologist. Cackovic says they may recommend skin-lightening agents, chemical peels or laser and light therapies to try to get the line to fade. Another tip? Use a good SPF when your stomach is exposed. The sun’s UV rays can exacerbate patches of hyperpigmentation.

You may not be thrilled with the look of your pregnant belly line, but try not to focus on it, and be patient. “Remember that your body has amazingly grown a baby, and your body will never quite be the same—and that’s okay,” Lamppa says. The linea nigra is proof that you can do amazing things.

About the experts:

Michael Cackovic, MD, is a maternal-fetal medicine physician at the Ohio State University Wexner Medical Center. He received his medical degree at the MCP Hahnemann University College of Medicine.

Christine Greves, MD, is an ob-gyn at the Winnie Palmer Hospital for Women & Babies in Orlando, Florida. She received her medical degree from the University of South Florida.

Julie Lamppa, APRN, is a certified nurse-midwife at the Mayo Clinic and the author of Obstetricks. She earned her degree at the University of Minnesota Medical School in Minneapolis.

Jessica Shepherd, MD, is an ob-gyn and founder of Sanctum Med + Wellness in Dallas, Texas. She received her medical degree from Ross University School of Medicine in Barbados.

Please note: The Bump and the materials and information it contains are not intended to, and do not constitute, medical or other health advice or diagnosis and should not be used as such. You should always consult with a qualified physician or health professional about your specific circumstances.

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Can you get the pregnancy line in early pregnancy?

What does the line on pregnant belly mean?

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