Linea nigra: What that pregnancy belly line means and why it appears

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  • If you have noticed a line on your stomach during pregnancy, you're not alone! It's known as the linea nigra and many women have this vertical line on their belly when they're expecting.

    The linea nigra is a latin term which literally translates to ‘black line’. It is the name used to describe the dark vertical line which often appears on the abdomen of pregnant women around the middle of pregnancy.

    Developing a linea nigra during pregnancy is very common and it’s no cause for alarm. It’s estimated that around 75 per cent of pregnant women will experience some evidence of linea nigra during their pregnancy. It can be darker on some and lighter on others and some people believe that the way the line extends over your belly can even be used as a baby gender predictor.

    Pregnancy is an exciting, amazing and scary time. It’s a rollercoaster of emotions for women and the way the body changes in pregnancy can be both strange and wonderful. This dark line which seems to appear overnight during the second or start of the third trimester is part of many alterations you will see you skin go through in pregnancy.

    What is the linea nigra?

    The linea nigra is simply a line that forms, running vertically on the pregnant belly. “Some women experience significant skin changes in the 2nd trimester, mostly resulting in darkening of the skin”, says midwife Marie Louise, founder of The Modern Midwife and author of Pregnancy, Birth and Beyond.

    The dark line generally appears to run from the umbilicus (your belly button) and runs straight down to the pubic bone. But it can also run from the umbilicus upwards, towards (and almost level with) the ribcage.

    It may be a slight shade of brown or a darker pigment to almost black in colour. You will likely start to notice it from during the second (weeks 13 – 26) and third (27 – 40 weeks) trimester. In the same vein, dark lines may also appear around your belly button, areolas and vagina too, but they should all disappear nine to 12 months after birth.

    pregnancy - linea nigra

    Credit: Getty Images

    Why does the linea nigra develop?

    The reason the linea nigra develops is all down to hormones. When you’re pregnant, your hormones go through unique changes. For example, a woman will produce more estrogen during one pregnancy than throughout her entire life when not pregnant.

    Women develop a linea nigra because of an increase in the melanocyte stimulating hormone which causes skin cells to darken. This is specifically down to high levels of oestrogen, which has a direct effect on the melanocyte stimulating hormone which is manufactured by the placenta.

    Darkening of the skin can happen to pregnant woman due to stimulation of pigment-producing cells by female sex hormones so that they produce more melanin pigments. This process is referred to as melasma and is nothing to worry about.

    However, melasma can increase your skin’s sensitivity to the sun, so it’s a good idea to invest in some good suncream with strong SPF. Midwife Marie Louise advises, “Some women get darker patches on the forehead or cheeks, if this is the case ensure you protect your skin from the sun.”

    Is the linea nigra supposed to be straight?

    No, there’s no need to worry if your linea nigra is not completely straight. It can look different from woman to woman. Linea nigras can be crooked, completely straight, or squiggly, and none of these are any cause for concern. It’s simply how the pigmentation has formed on your skin.

    Can the linea nigra predict the gender of my baby?

    Like the popular Nub Theory or the ancient Chinese birth chart, there are some old wives tales about pregnancy that say you can predict the gender of your baby by analysing your linea nigra.

    Unlike the Nub or Skull Theory which rely on a scan photo to determine the sex of your baby, to work out if your are having a boy or girl using your linea nigra all you have to do is look at your stomach and the way the line extends across your skin.

    Apparently, if the line extends from your navel downwards towards your pubic bone then you’re more likely to have a girl. However, if your linea nigra is heading ‘north’ – from your navel up towards your head – then you are more likely to have a boy. However, there’s no conclusive evidence that this method of predicting your baby’s gender is accurate and ultrasound scans are the best – and most scientific! – way to find out your baby’s gender.

    What is the linea nigra actually for?

    Midwife Marie Louise explains that the development of the linea nigra is part of the body’s natural evolution and is designed to help your baby to find the breast.

    Midwife Marie Louise explains, ‘The linea nigra is perfectly normal, it’s a hormonal change and there mainly to facilitate darkening of nipples so that your baby is able to see the his/her target for breastfeeding.”

    The dark line acts as a direction from mum’s pregnant belly up towards the darkened areola, for baby to latch on. In the days before modern medicine, newborns were left with mum skin-on-skin straight from birth. It was in this time that baby would instinctively shimmy up the belly, nuzzling to find the breast.

    It is believed that the scent of the mother’s nipple is similar to the amniotic fluid, which surrounds the foetus for nine months so the baby recognises and trusts it.

    Will linea nigra harm me or my baby?

    No, the linea nigra is not harmful at all. Its seemingly sudden appearance might seem shocking at first, but experts have agreed the line is cosmetic and is not going to harm mum or baby. You don’t need medical treatment if you develop a linea nigra and it’s nothing to be concerned about.

    linea nigra

    Credit: Getty Images

    What can I do to prevent linea nigra?

    There’s nothing you can do to prevent the line from developing, but if you really want to help it fade quicker, you can consult a dermatologist about using certain creams to help it fade after pregnancy. However, it’s very important to note that you should not use these creams during pregnancy as it can be harmful to your baby.

    If you really want to hide the line during your pregnancy, it’s much safer to use a makeup concealer over any strong creams. For most women, the pigmentation usually disappears after birth, and Marie Louise adds, “The changes usually go after birth but it’s important to also use sun cream postnatally as darker skin patches or linea nigra may reappear in the sun.”

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