The nigra line

The nigra line

The linea nigra (black line) looks like a dark brown line that runs vertically through the abdomen, from the pubic area to the navel and beyond.

It is usually about ten millimeters wide and tends to darken as pregnancy progresses.

The causes of its appearance

Like most skin changes that occur during pregnancy, the appearance of linea nigra is due to increased hormone levels during the second and third trimesters of pregnancy.

This line, in reality, is nothing more than a hyperpigmentation of the linea alba, which in all humans is formed by muscles that cross their bundles on the midline of the anterior abdominal wall and by their own fibers.

Before pregnancy this hyperpigmentation remains practically invisible, while the increased production of melanin caused by the high hormonal levels of pregnancy makes it darker and more evident.

Predisposing factors

Risk factors for the appearance of the black line are related to the following conditions.

  • To the fact of belonging to an ethnic group with dark skin (such as Asians or Africans): this is due to the fact that the increased pigmentation of the skin increases the chances of hyperpigmentation, and leads to the formation of the black line and the pregnancy mask, a skin blemish known as chloasma gravidarum.
  • To the fact of exposing oneself to direct sunlight, since UV rays worsen hyperpigmentation, and lead to the formation of a darker line.

When it manifests itself

Most women notice the appearance of linea nigra towards the end of the first trimester, or during the second trimester of pregnancy.

The fact that this line darkens as the pregnancy progresses is completely normal.

Women who are expecting twins may notice the onset of linea nigra earlier — during the first trimester — and that’s because hormone levels in twin pregnancies are higher.

When it disappears

In most cases, the dark line gradually disappears after delivery, when hormone levels fall within normal values.

Thus, it is normal that it remains even during the following months of breastfeeding.

It usually takes a year to lose that dark pigmentation, but it may never go away completely.

Is it possible to do something to remove the linea nigra?

There is no way to get rid of it during pregnancy. However, you can take precautions to control belly pigmentation. Here’s how.

  • Wear protective clothing or sunscreen to protect your belly from direct exposure to sunlight.
  • Eat many foods rich in folic acid, also take the appropriate vitamin supplements: in fact, some scientific studies have shown that a folic acid deficiency can be linked to hyperpigmentation.
  • Apply fresh lemon juice to the affected area, or massage it with alcohol in order to lighten pigmentation.

Before considering these methods, you should of course consult your doctor.

However, the use of any lightening cream should be avoided, or to undergo laser therapies due to the potential dangers to the fetus.

Some curiosities about the nigra line

According to widespread popular beliefs,

  • the fact of having a linea nigra that starts from the pubic area and stops at the navel, indicates that you are pregnant with a female;
  • Conversely, if the line extends beyond the navel or just below the ribcage, it means that you are pregnant with a male.

Still with regard to the gender of the unborn child, according to another myth, a broken line indicates it as female, while a straight line indicates it as male.

However, there is no scientific evidence to support these beliefs!

Katherine Johnson, M.D., is a board-certified obstetrician-gynecologist with clinical expertise in general obstetrics and gynecology, family planning, women’s health, and gynecology.

She is affiliated with the Obstetrics and Gynecology division at an undisclosed healthcare institution and the online platform,

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