(provided by babycenter.com)
Why do they call it morning sickness when I feel nauseated all day long?
"Morning sickness" is really a misnomer. (In fact, the technical medical term is "nausea and vomiting of pregnancy.") For some pregnant women, the symptoms are worst in the morning and ease up over the course of the day, but they can strike at any time and last all day long.
About three quarters of pregnant women experience nausea and sometimes vomiting during their first trimester. The nausea usually starts around six weeks of pregnancy, but it can begin as early as four weeks. It tends to get worse over the next month or so.
About half of the women who get it feel complete relief by about 14 weeks. For most of the rest, it takes another month or so for the queasiness to ease up, though it may return later and come and go throughout pregnancy.
What causes nausea and vomiting during pregnancy?
No one knows for sure what causes nausea during pregnancy, but it's probably some combination of the many physical changes taking place in your body. Some possible causes include:
• Rapidly rising levels of the hormone human chorionic gonadotropin (hCG) during early pregnancy. No one knows how hCG contributes to nausea, but the timing is right: Nausea tends to peak around the same time as levels of hCG.
Estrogen, another hormone that rises rapidly in early pregnancy, is also considered a prime suspect, and it's possible that other hormones play a role as well.
• An enhanced sense of smell and sensitivity to odors. It's not uncommon for a newly pregnant woman to feel overwhelmed by the smell of a bologna sandwich from four cubicles away, for example, and that certain aromas instantly trigger her gag reflex. This may be a result of higher levels of estrogen.
• A tricky stomach. Some women's gastrointestinal tracts are simply more sensitive to the changes of early pregnancy.
You may have heard that morning sickness can be caused by a vitamin B deficiency. While taking a vitamin B6 supplement does seem to help ease nausea in many pregnant women, this doesn't mean they have a vitamin deficiency. In fact, at least one study has shown no significant differences in the levels of B6 in women with morning sickness and those without.
No one knows why B6 is helpful. There's also some evidence that taking a multivitamin at the time of conception and in early pregnancy helps prevent severe morning sickness, but again, no one knows why.
Some researchers have proposed that certain women are psychologically predisposed to having nausea and vomiting during pregnancy as an abnormal response to stress. However, there's no good evidence to support this theory. (Of course, if you're constantly nauseated or vomiting a lot, you certainly may begin to feel more stressed!)
Are some pregnant women more likely than others to feel nauseated?
You're more likely to have nausea or vomiting during your pregnancy if any of the following apply:
• You're pregnant with twins or higher multiples. This may be from the higher levels of hCG, estrogen, or other hormones in your system. You're also more likely to have a more severe case than average. On the other hand, it's not a definite thing — some women carrying twins have little or no nausea.
• You had nausea and vomiting in a previous pregnancy.
• You have a history of nausea or vomiting as a side effect of taking birth control pills. This is probably related to your body's response to estrogen.
• You have a history of motion sickness.
• You have a genetic predisposition to nausea during pregnancy. If your mother or sisters had severe morning sickness, there's a higher chance you will, too.
• You have a history of migraine headaches.
• You're carrying a girl. One study found that women with severe nausea and vomiting were 50 percent more likely to be carrying a girl.
