Generality
The nigra line is a dark-colored skin that appears in the middle of the abdomen, usually starting from the second trimester of pregnancy .
This phenomenon is physiological and quite common. The nigra line depends, in fact, on the strong hormonal stimulation typical of pregnancy, which increases the production of melanin and causes a hyperpigmentation of the skin .
This manifestation usually disappears within a few weeks of birth, completely spontaneously and without treatment.
Note
During pregnancy, the nigra line may appear in some women, while in others it may not. This sign is more evident in future mothers with a dark complexion and can become more pronounced following exposure to sunlight.
In any case, the nigra line is by no means an indicator of the evolution of pregnancy.
Features
The nigra line is a vertical skin sign, in shades from brown to dark brown, and about one centimeter wide.
This hyperpigmentation extends along the center of the belly up to the pubis, crossing the navel; in some women, however, this strip can reach the upper part of the abdomen or the area under the breasts.
The position of the darker skin strip coincides with the alba line . During pregnancy, in fact, this fibrotic structure, located in the middle portion of the abdomen, can become hyperpigmented due to the action of estrogen hormones, thus giving rise to the nigra line. The latter generally appears near the fourth or fifth month of gestation, presenting itself as a very thin line, which slowly expands and gradually becomes darker. However, it is not impossible to exclude that the nigra line manifests itself already around the fourteenth week or, on the contrary, it is never evident.
What is the linea alba?
The linea alba is located between the margins of the two rectus muscles and is formed by the aponeurosis of the external oblique muscle, the internal oblique muscle and the transversus muscle.
Causes
The nigra line generally appears near the second trimester, due to the strong hormonal stimulation typical of pregnancy.
The increase in estrogens has, in particular, an effect on the melanocyte-stimulating hormone that is produced by the placenta.
The action of these hormones stimulates the production of melanin, making a brownish line emerge from the pubis to the navel and, sometimes, to the lower part of the sternum. The nigra line originates from the resulting hyperpigmentation phenomenon.
The increase in melanin production also affects other areas of the face and body, such as the sides of the nose, upper lip, cheeks and forehead (the so-called chloasma gravidarum), areolas, vulva and inner part of the thighs. The skin of these areas may become darker, as well as any scar tissue, freckles and snow may appear more noticeable than before.
After giving birth, the nigra line tends to lighten, until it disappears completely within a few months, although in some women the return to normal pigmentation can take up to a year.
Changes in skin pigmentation during pregnancy
- Some changes in skin pigmentation are quite common during pregnancy. For example, it is common for skin blemishes, moles and freckles to darken.
- On the skin of the face, instead, it is possible the emergence of chloasma (or gravidic mask), determined by a phenomenon similar to that which the nigra line causes.
- Moreover, due to the high concentration of estrogens, it is possible that also the stellate angiomas appear, that is small aggregates of blood vessels that can appear in any part of the body.
- These changes in pigmentation normally disappear within six months after delivery but, in some cases, they can last longer or even be permanent.
When it appears
Usually, the nigra line appears only and exclusively during pregnancy.
This sign is evident after the twenty-second week of gestation, even if there is no precise rule (it is not possible to establish with certainty if and when it will appear).
Furthermore, it does not occur in all women and its appearance depends, in part, on the type of complexion.
Women with fair skin are less likely to develop a nigra line than those with a darker complexion.
Furthermore, in women with dark skin, the line tends to appear earlier, around the fifth-sixth month of pregnancy; in other future mothers, this sign appears in the last three weeks, while in others it never appears or is very mild and not very visible. At times, the nigra line is confused with stretch marks.
Exposure to sunlight can accentuate this temporary phenomenon.
When it disappears
The nigra line usually disappears within a few weeks after birth, in a completely spontaneous and gradual manner. Therefore, no specific treatment is necessary, but, like the other hyperpigmentations typical of pregnancy, the advice to keep the skin elastic and well hydrated during the nine months of gestation, through the constant use of creams and oils, remains appropriate. natural. Furthermore, it is always good to expose yourself to the sun with a high protection cream.
Only rarely, the nigra line can be permanent after the birth of the child; in this case, you should contact your doctor to find the most suitable treatment.
Popular beliefs
The appearance of the nigra line in pregnancy has given rise to various popular beliefs.
In the past, it was believed that depending on the different extension of the line the sex of the newborn could be deduced: if the dark mark was directed towards the upper part of the abdomen the unborn child would probably have been a sissy; otherwise, that is, in the event that the line had gone from the navel to the pubis, it would have been a boy.
In reality, the nigra line manifests itself due to the strong hormonal changes typical of this period, without any correlation with the sex of the child.
Remedies and prevention
The nigra line is a temporary phenomenon, which tends to disappear gradually and spontaneously after birth.
However, to help restore normal pigmentation it is possible to implement some tricks, such as:
- Protect the skin from ultraviolet rays : excessive exposure to the sun during pregnancy increases the probability of having a more pronounced dawn line. To reduce the risk of developing or accentuating this sign, it is recommended to apply a sunscreen with a high or total protection factor on the face and areas of the body most exposed to the sun. Furthermore, it is also important to avoid exposure to the sun at times of higher UV radiation, ie between 11 and 15.
- Take food with folic acid : some scientific studies claim that the appearance of the nigra line and other skin hyperpigmentations during pregnancy is related to a lack of folic acid. This B group vitamin is essential for the proper development of the baby's organs. For this reason, a proper and rich diet is recommended in foods that can bring the right substances to the body, such as green leafy vegetables (spinach, broccoli, lettuce and other asparagus), oranges, tangerines, lemons, cereals, legumes, kiwi and strawberries.
- Using cosmetics: during pregnancy, it is important to keep the skin elastic and well hydrated, through the constant use of creams and natural oils.
After giving birth, the application of cosmetics based on vitamin A (topical retinoid) or vitamin E (also known as tocopherol), an ingredient widely used to keep the skin smooth and hydrated, can contribute to the depigmentation of the nigra line. A "natural" alternative may be the application of lemon juice; however, its effects are variable and - if not properly diluted with water - can cause irritation and burning.
- Making a scrub : during the bath, it can be a good habit to exfoliate the skin of the belly with a loofah sponge, a gommage or a scrub to stimulate cell turnover.
What not to do
During pregnancy, it is important to avoid applying cosmetic products with bleaching agents to lighten skin hyperpigmentation at the nigra line, in particular those containing hydroquinone. In fact, these types of products have not proved safe for use during pregnancy or during breastfeeding.
Another trick is to avoid the application on the nigra line of any drugs for the treatment of acne (in particular those that contain substances such as salicylic acid, doxycycline, minocycline and tetracycline).
