When you're pregnant, almost everyone is eager to offer advice and a blueprint of what to expect during this monumental time. But moms-to-be may find that some aspects of pregnancy are rarely discussed. Here, we disclose some of pregnancy's best-kept secrets:

Morning sickness isn't limited to the morning. Contrary to what its name suggests, morning sickness, which may include nausea and vomiting, can occur at any time of day. Nausea is often a result of the increased hormones in your body and usually tapers off after the first trimester of pregnancy. On the plus side, many health-care providers feel that morning sickness is a good thing, because it means the placenta is developing normally. To help alleviate your symptoms, experts suggest eating small meals throughout the day, staying hydrated, and avoiding warm places, as heat can contribute to nausea.

"The blues" may find you. Pregnancy can be one of the happiest times in a woman's life, but for many expectant mothers, it's also a time of fear, stress, and confusion. 10 to 20 percent of women will struggle with some symptoms of depression during pregnancy, also known as perinatal depression. If you believe you or a loved one may have symptoms of depression, it's important to talk with your health-care provider immediately.

You could become forgetful. Women who become a bit scatterbrained during pregnancy can attribute it to more than just a busy schedule.Pregnant women do, in fact, experience a slight decline in memory. The memory loss may last up to one year after giving birth.

Your skin pigment may change. Many of us believe that all pregnant women "glow" with health and anticipation of motherhood. Well, some women do, but others may develop brownish or yellowish patches on their faces called melasma, also known as the "mask of pregnancy." Up to 70 percent of pregnant women experience this condition. These skin changes are the result of pregnancy hormones, which cause the body to produce more melanin. Melasma can't be prevented, but wearing sunscreen and avoiding UV light can minimize its effects. Fortunately, it usually fades within a few months of giving birth.

Sitting down might be a pain. Many women experience hemorrhoids during pregnancy, particularly during the third trimester. Hemorrhoids, also known as piles, are varicose veins in the rectal area that can become extremely uncomfortable and bothersome. Hemorrhoids during pregnancy may be caused by straining during bowel movements, excess weight during pregnancy, or the pressure of sitting or standing for long periods of time. Drinking plenty of water, eating a high-fiber diet, minimizing weight gain, and getting regular exercise can help decrease your chances of developing this uncomfortable condition.