Pigmentation
When you are pregnant, it’s possible for the cells that produce pigmentation in the skin to go a little crazy.  This results in parts of your body getting darker than other parts.  A lot of women notice that they have darker moles or even additional moles at some point in the pregnancy (for me this happened around 6 months).  This change in the color of your moles can be permanent.

You can also have localized darkening of this skin.  This most commonly happens in the underarms, groin, belly, and neck.  My underarms got really dark while I was pregnant.  From far away it looked like my underarms were hairy!  I was pretty embarrassed by it and covered it up with shirts that covered my underarms.  My groin area also got a lot darker.  I was not aware of this until after I had my baby because I could not see my groin!  A lot of women will get a line of pigmentation on their bellies.  This line will run all the way to the pubic region, through the belly button, up to the chest line.  When I first saw this line coming in on my belly, I thought it was hair.  Some women get what is called “the mask of pregnancy”.  This is when the neck becomes discolored.  All of these areas of discoloration are not normally permanent and should fade after the baby is born.  This pigmentation can be partially prevented by avoiding direct contact with the sun or UV light.  Yet another reason to slather on the sun block (be careful to use a sunblock that has safe ingredients in it!). 

Skin tags
Another wonderful side effect of pregnancy.  Skin tags are similar to moles except that they are almost always benign growths.   They are normally the size of a rice grain or smaller.  Skin tags will most commonly appear on the skin above regions that have lymph nodes (the neck, underarms, and groin).  Skin tags are generally painless and can be removed after the baby is born.  I had a skin tag under my arm that rubbed the wrong way when I moved my arm.  The skin tag actually got twisted around itself and died.  It was pretty gross.  Part of it ended up falling in a shower – nasty!    

Weight gain
Ugh, weight gain.  Most women will gain some (or a substantial amount of) weight while they are pregnant.  How much weight you should gain depends on your weight before you were pregnant and how many babies you are carrying.  Recommended weight gain and actual weight gain are two different things.  My doctor wanted me to gain no more than 25 pounds while I was pregnant.  I failed.  Miserably.  I don’t really want to go into numbers here, but basically I gained a third of my original body mass when I was pregnant.  So let’s pretend I weighed 100 pounds before I got pregnant (that would have been nice).  Gaining a third would put me at 133 pounds the day the baby was born. 

My advice: While you’re pregnant, it’s important that you eat right since you are feeding the baby.  That doesn’t mean you are “eating for two”.  It means eating lots of fruits, vegetables, whole grains, and dairy and only adding about 300-500 calories to each day’s meals.  Don’t worry about the weight if you are eating as healthy as possible.  When you’re pregnant, your weight will be closely monitored by your doctor and if you have any concerns you should mention them. 

Stretch marks
Some women get them, some don’t.   I thought I was in the clear because I didn’t have a mark on my body all the way up to about 7 months.  And then BAM.   Red marks started spreading from the sides of my body to my hips.  Also, once my breasts started enlarging, they also got stretch marks.  If you want to know if you will get stretch marks or not, ask your mother if she has them.  If your mother has stretch marks, you will probably get them too.  These can appear on your belly (duh), legs, back, arms, boobs… pretty much anywhere that you gain weight while you are pregnant.  Different women swear by different products and oils to use while pregnant to prevent stretch marks.  The research about these products is not very clear in terms of their effectiveness.  I put an expensive cream (Trilastin) on my belly and boobs every night.  I still have the marks but they are fading (slowly!).  Stretch marks will, in time, fade.