Effects on your skin may be noticeable from about 20 weeks onwards. The darker your skin, the more likely you are to see changes. If you're very fair or have red hair you may not notice any at all. Pigmentation changes may mean:
Your nipples deepen in colour. They may appear to get larger and more prominent. The areola around the nipple may spread. A linea nigra, or dark line, appears down the middle of your chest and tummy.
Some women have a mask-like colouration on the face, which can be irregular and blotchy.
Uneven tanning when in the sun or using sunbed. While there's no evidence that sunbathing or sunbeds are harmful to your baby, some tanning shops advise against using sunbeds while pregnant.
Moisturising bath and shower products may help if your skin is dry or itchy.
In rare cases if your skin is very itchy all the time, mainly on your torso, it can be a sign of a condition called cholestasis, which affects the liver and kidneys. This can be harmful to your baby, so talk to your midwife or doctor.
Stretch marks are most likely to appear on your tummy, breasts and thighs from about six months onwards. They're the outward sign of broken elastic fibres in the skin and look red at first, but fade to silver-grey.
There are creams and gels that claim to reduce them, but they can't do that much as the breaking of the fibres occurs some way beneath the skin's surface. The tendency to stretchmarks seems to run in families, so if your mum got them you're more likely to get them too.
Hair can look shiny and thick in pregnancy, probably because normal daily hair loss slows down. After the birth you may feel as though your hair's falling out more quickly. It's probably the contrast you're noticing, rather than anything more serious, but speak to your doctor if you're worried.
It's fine to use hair colourants and perm lotions on your hair, although you may find the results are unpredictable. This may be because hair can be more porous in pregnancy, affecting the way it reacts to a product.