Linea nigra: What that pregnancy belly line really means

Wondering what that pregnancy belly line – or linea nigra – really means?

Pregnancy is an exciting, amazing and scary time – it’s a rollercoaster of emotions for women, and your body is going through so many weird and wonderful changes.

We’re not just talking about the bump that will soon be protruding – your skin will go through some alterations too, including a dark line which seems to appear overnight during the second or third trimester.

The linea nigra is a latin term which literally translates to ‘black line’, and describes the dark vertical line which so often appears on the abdomen of pregnant women.

It’s estimated that around 75 per cent of pregnant women will experience some evidence of linea nigra – it can be darker on some and lighter on others.

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 darkening of the skin,’ says midwife Marie Louise.

‘Some women get darker patches on the forehead or cheeks, if this is the case ensure you protect your skin from the sun.’

The linea nigra 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 – with the ribcage.

It may be a slight shade of brown or a darker pigment to almost black in colour.

You will start to notice it from during the second (weeks 13 – 27) and third (29 – 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.

Why does the linea nigra develop?

It’s all down to hormones. Oh yes, they’ve been a constant in your life, from moodswings during your period, to that cluster of chin spots which appear as if from nowhere and for no reason. When you’re pregnant hormones make their comeback with a vengeance and it’s not just monthly, it’s for nine whole months.

The linea nigra is due to 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.

Can the linea nigra predict the gender of my baby?

There are so many old wives tales out there about how to find out the gender of your baby, and the linea nigra is definitely one of them.

Apparently, if it 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 to prove that this will always be the case.

What is the linea nigra actually for?

It has been said by many a midwife that the body’s natural evolution meant that the development of the linea nigra was specifically to help baby 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 of the linea nigra 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.