If you're pregnant, there's an 80 percent chance you're going to grapple with nausea and vomiting for the first few months. "Morning sickness," as it's called (though it can happen at any time of day), is the most common side effect of pregnancy. But statistics provide little comfort when you're heading off to work each morning feeling queasy.

Morning sickness appears to be linked to shifting levels of two hormones — human chorionic gonadotropin (hCG) and estrogen — which are produced by the placenta and fetus and cause the stomach to empty more slowly. Nausea is more common in first pregnancies, in young women, and in women carrying multiple fetuses.

But morning sickness isn't all bad. Studies have revealed that morning sickness may actually be good for your developing fetus. A study in the Journal of Obstetrics and Gynecology released in May 2000 suggested that morning sickness could help regulate levels of insulin in a pregnant woman's bloodstream, particularly during the early stages of pregnancy when bloodstream insulin levels tend to increase. Insulin, which is released in response to food intake, regulates blood sugar levels. As insulin levels increase in the bloodstream, more fat is metabolized. It appears that during early pregnancy, vomiting keeps insulin levels down, thus slowing fat metabolism. This is beneficial to the fetus because it ensures there are enough nutrients to fuel its early development.

For most women, nausea is an unpleasant but manageable side effect of early pregnancy. However, a small number of unlucky women will suffer from hyperemesis gravidarum: severe and persistent nausea and vomiting. If you experience persistent nausea and vomiting, and are unable to keep yourself hydrated or eat balanced meals, talk with your physician to work out a treatment plan.

Sources: Mayo Clinic HealthOasis; American College of Obstetrics and Gynecology; March of Dimes: 888-MODIMES, www.modimes.org; www.nacersano.org

Reviewed 12/00 by Jane Forester, MD

The information on this Web site is designed for educational purposes only. It is not intended to be a substitute for informed medical advice or care. You should not use this information to diagnose or treat any health problems or illnesses without consulting your pediatrician or family doctor. Please consult a doctor with any questions or concerns you might have regarding your or your child's condition.

Content courtesy of American Baby.