What is the purple line in pregnancy?

What is the purple line?

The purple line, also known as Chadwick’s sign, refers to a dark vertical line that appears on a pregnant woman’s lower abdomen during the later stages of pregnancy. This line typically runs from the pubic bone to the belly button, along the midline of the abdomen. It is often described as having a purple, blue, or reddish hue. The purple line is a normal occurrence during pregnancy and is not cause for concern.

What causes the purple line?

The purple line is caused by increased blood circulation and pigmentation changes related to pregnancy hormones. Here are some key factors:

– Increased blood flow – During pregnancy, blood volume increases dramatically to supply oxygen and nutrients to the growing baby. This increased blood flow causes more blood vessels near the surface of the skin to become noticeably visible, taking on a blue or purple hue.

– Pigment changes – Pregnancy hormones like estrogen and melanocyte-stimulating hormone cause the body to produce more melanin, the pigment that gives skin its color. This increase in melanin production leads to darker pigmentation along the midline skin of the lower abdomen.

– Stretching/changes to connective tissue – As the abdomen expands during pregnancy, connective tissue and skin along the midline becomes thinner and more translucent. This makes the blood vessels more visible.

When does the line appear?

The purple line usually appears sometime after the first trimester, in the second half of pregnancy. The line tends to become more prominent and defined as pregnancy progresses. Here is the typical timeline:

– 16-20 weeks – The line may first become noticeable around this stage of pregnancy. At this point, it is often faint and irregular.

– 24-28 weeks – The line darkens and lengthens, running vertically down the length of the abdomen.

– 32-36 weeks – Now very visible, the purple line is darker and well-defined during the third trimester.

– 40 weeks – Nearing delivery, the line is typically at its darkest and most prominent. It may begin fading after childbirth.

The exact timing can vary between women. Factors like skin tone, number of pregnancies, and individual differences in melanin production can affect when the line appears and how dark it gets.

Does every pregnant woman get the line?

Most pregnant women will develop a visible purple line by the third trimester. Estimates range from 70-90% of pregnant women exhibiting Chadwick’s sign. However, there are some women who never notice a distinct purple line during pregnancy. Here are some reasons why it may not appear:

– Light skin tone – The line shows up more easily in women with darker skin tones. It may be hard to see on women with very fair skin.

– Location of linea nigra – The dark vertical line running down the abdomen often overlaps or obscures the purple line.

– Minimal skin changes – Some women experience less stretching/thinning of the abdominal skin during pregnancy.

– Individual variations – Skin pigmentation, melanin levels, and blood flow changes can vary, affecting line visibility.

– Too early in pregnancy – The line may not have darkened and developed enough yet earlier on in pregnancy.

Is the purple line a sign of anything?

The purple line is primarily a cosmetic change related to pregnancy itself. It does not signify any specific complications or conditions. However, it is sometimes associated with the following:

– Progressing pregnancy – A clearly defined purple line is often a sign of healthy blood flow and changes to the skin. As pregnancy advances, the line darkness and definition tend to increase.

– Potential diabetes – Some research indicates the line may be more prevalent and visible in women with gestational diabetes. The cause is not fully known.

– Possible twin pregnancy – When very prominent early on, some have hypothesized the purple line could indicate higher hormone levels from a twin pregnancy. However, no definitive link has been established.

Overall, the purple line is considered a normal physical sign of pregnancy. Talk to your doctor if you have any concerns about your specific symptoms.

Are there any complications associated with the purple line?

There are no medical complications or risks directly associated with the purple line itself. As a purely cosmetic change to the skin, the line does not cause health problems for mother or baby.

However, some women may experience itchiness, irritation, or skin sensitivity along the area where the line develops. This is likely due to the rapid stretching of the skin over the abdomen. Using lotions and moisturizers may provide relief. Contact your doctor if symptoms do not improve.

In rare cases, the purple line may coincide with other problematic symptoms that do warrant medical attention:

– Severe itching/skin changes – Signs of intrahepatic cholestasis of pregnancy like jaundice or excessively itchy skin deserve examination.

– High blood pressure – A very dark or prominent line along with symptoms like headache or vision changes can indicate preeclampsia.

– Excessive swelling – Rapid swelling alongside the purple line can signal preeclampsia or other concerns.

Overall though, the purple line alone is not dangerous. Focus on other symptoms you may be experiencing and discuss any worries with your obstetrician.

How long does the purple line last after pregnancy?

After giving birth, the purple line will usually start fading within the first 1-2 weeks postpartum. Some residual darkness or faint shadowing may linger up to several months later.

Here is a general timeline for how the purple line changes after delivery:

– First 48 hours – Initially, the line remains dark and defined.

– 3-5 days – It should begin noticeably lightening in color and width.

– First week – The line will appear fainter, smaller, and likely disjointed.

– 2-4 weeks – It continues lightening and shrinking, only faintly visible in some spots.

– 2-3 months – Most residual lining and pigmentation is gone, abdomen returns to a pre-pregnancy appearance.

– Up to 6 months – In some cases, faint shadowing can remain but will eventually fade with time.

The purple line may disappear at a faster or slower pace depending on individual factors like skin elasticity, melanin levels, and genetics that affect postpartum changes. But it is generally expected to fully resolve within the first 6 months after delivery as abdominal skin returns to normal.

Can the purple line reappear with future pregnancies?

Yes, it is common for the purple line to reappear during subsequent pregnancies after fading postpartum. Because it relates to normal skin/circulatory changes that occur again with a growing fetus, the line typically recurs with each full-term pregnancy.

However, women who have birthed multiple children often note the purple line appears earlier and becomes darker quicker with each additional pregnancy. This may relate to already stretched abdominal skin and existing pigmentation.

While not necessarily permanent, the purple line can come and go as a woman progresses through her childbearing years and pregnancies. It tends to follow a similar pattern with each pregnancy – appearing in the second trimester, darkening by the third, and slowly resolving after giving birth.

Is there anything that can be done to prevent or reduce the purple line?

Because the purple line stems from common pregnancy-related changes to the skin and circulation, there is no way to fully prevent it. However, some women may wish to minimize its appearance. Here are a few tips that may help:

– Apply lotions frequently – Keeping the skin moisturized can improve elasticity and reduce the thin, stretched appearance.

– Exfoliate gently – Light exfoliation may help slough off accumulated pigmentation. But scrubbing too hard can cause irritation.

– Avoid sun exposure – Sun exposure can make pigmentation changes worse. Use sunscreen or cover up when outdoors.

– Wear loose clothing – Tight pants, skirts or dresses can exacerbate thinning of the abdominal skin.

– Manage weight gain – Gaining weight at a steady, healthy pace can limit excessive stretching.

– Try skin lighteners – In some cases, dermatologist-recommended lightening creams may lessen the darkness after pregnancy.

However, most women view the line as a harmless effect of pregnancy they do not try to remove. Focus on maintaining skin health, but recognize the purple hue is difficult to prevent entirely.

When to see a doctor

The purple line alone does not require medical assessment. However, you should contact your healthcare provider if you have additional concerns such as:

– Itchiness or pain along the line
– Jaundice (yellowing skin)
– Abdominal swelling and high blood pressure
– Severe rash or skin changes
– The line appears much earlier or darker than typical

Discuss any noticeable changes from your normal pregnancy symptoms with your doctor, even if they may be harmless. Stay vigilant about potential signs of preeclampsia or cholestasis that would need prompt treatment.


In summary, the purple line is a common, harmless skin change during pregnancy. Caused by increased abdominal blood flow and pigmentation changes, it runs vertically down the abdomen in most women by the third trimester. The line starts fading after delivery as skin and circulation return to normal. While no complications directly stem from the purple line itself, contact your doctor about bothersome or unusual symptoms. With this knowledge of Chadwick’s sign, you can rest assured it is simply part of a healthy, progressing pregnancy.

Leave a Comment