Linea Nigra: Why the Line Appears on a Pregnant Belly

A brown line has appeared down the middle of your belly, and someone has already told you it means you are having a boy.

It does not. It has a name, a cause, and an ending.

What it is

Linea nigra is Latin for black line, which oversells it. The line is usually brown.

• Darker than the skin around it
• Running vertically from your pubic bone to your navel, sometimes higher
• Roughly half a centimetre to just over a centimetre wide
• Usually turning up around the fifth month

It was there before you were pregnant, as linea alba, the white line. Pigment has simply made it visible.

Why it appeared

Rising oestrogen and progesterone stimulate melanin, the pigment that darkens skin.

The same process is darkening other things at the same time: scars, birthmarks, your nipples, your underarms, your inner thighs. One mechanism, several changes.

Dr Michelle Tollefson, an obstetrician-gynaecologist, notes that up to 75% of pregnant women get this hormonal darkening. It is one of the most common skin changes there is.

Exactly why it forms this particular line is still not fully understood, which is a satisfying thing to be able to say about something so common.

It is harmless

No problem for your pregnancy and none for your baby. No medical treatment needed.

For some Mamas it is a source of self-consciousness, which is a fair reason to wish it gone. It is not a reason to worry about your health.

The myth

The story that the line predicts your baby's sex, depending on whether it runs above or below your navel, has no research behind it whatsoever.

It belongs in the same drawer as the wedding-ring test and the shape of your bump.

When it fades

Over the months after the birth, gradually, as your hormones settle. Most Mamas find it has gone or nearly gone somewhere between six months and a year.

It often comes back in a second pregnancy, usually earlier and sometimes darker, which surprises people who assumed it was a one-off.

Some of it lingers longer on deeper skin tones, because the pigment contrast is greater to begin with. That is not a sign anything is wrong, and it is worth knowing so you are not counting the months against someone else's timeline.

The other lines and patches

Once you know what is causing it, the rest of what is happening to your skin makes more sense.

Darker nipples and areolas. Very common, and the one change that often does not fully reverse.

Darker underarms, groin and inner thighs. Same mechanism, fades the same way.

Existing scars and moles going darker. Also normal. A mole that changes shape or outline rather than only shade is a different question and worth showing a doctor.

Melasma on your face, which is the same process on the one part of you that gets sun. That is why it needs sun protection when the line down your belly does not.

What not to bother with

Bleaching creams. They will not shift it, your skin there is thin, and unregistered whitening products still routinely turn out to contain mercury.

Scrubbing it. The pigment is in the skin, not on it. All you achieve is irritation, and irritated skin pigments more.

Lemon juice. Contains psoralens, which react with sunlight and leave the area darker than it started.

Waiting for a cream that works. There is not one, and the line goes on its own.

What makes it darker

Sun exposure, reliably. So keeping your belly out of direct sun is worth doing on beach days, and it is the only thing on this page you can actually act on.

Beyond that: no cream removes it, and none needs to. It fades over the months after the birth, on its own, whatever you do or do not put on it.