Morning sickness, nausea and vomiting during pregnancy, is experienced by at least 60 percent of pregnant women, according to Consumer Reports Health. It typically affects you during the first 12 weeks of pregnancy. Some women complain of nausea occurring throughout the day, while you may only suffer from morning symptoms. Severity of nausea also varies among women. While the exact causes of morning sickness remain unknown, hormonal fluctuations can play a major role.
Human Chorionic Gonadotropin
Human chorionic gonadotropin, or hCG, may contribute to morning sickness. Levels of hCG spike during the first trimester. This timing corresponds with nausea and vomiting associated with morning sickness. Mothers carrying two or more babies often experience increased severity of morning sickness symptoms. This is attributable to higher than normal levels of hCG present with a multiple pregnancy.
Olfactory Sensitivity
Many women say they notice heightened olfactory activity throughout early pregnancy. Certain smells, such as perfume, cigarette smoke, gasoline and food odors can trigger nausea. The National Health Service website suggests a possible link in odor sensitivity to the female sex hormone estrogen. A sudden increase in estrogen levels, particularly during the first trimester, might explain this adverse reaction to familiar odors.
Molar Pregnancy
A hydatidiform mole, or molar pregnancy, typically causes severe nausea. Rare molar pregnancies result from irregularities during the fertilization process, and an abnormal mass of tissue forms within the uterus. The tissue mass grows in place of, or in addition to, a compromised embryo. During early gestation, a hydatidiform mole can mimic a normal pregnancy. As the mass increases in size, symptoms include extreme nausea, vomiting and vaginal bleeding. Most molar pregnancies terminate spontaneously.
Gastrointestinal Changes
Gastrointestinal changes can contribute to morning sickness. During early pregnancy, progesterone levels increase. This hormone helps prepare the uterus to support the developing embryo. Elevated levels of progesterone slow motility in the small intestine, stomach and esophagus. Slow digestion can create an accumulation of caustic gastric juices in the stomach, leading to upset, nausea and vomiting.
Self-Treatment
You can reduce morning sickness symptoms by making simple dietary adjustments. Try eating small meals throughout the day instead of three large meals. Stay away from over-seasoned, fried and fatty foods. Avoid foods with bothersome smells. Include more carbohydrates such as white rice, dry toast and plain baked potatoes. To curb nausea, consume low-sodium saltine crackers, gelatin, clear broths and ginger ale.
Other Considerations
Call your health care provider if you have been unable to hold down food and fluids for more than one day, experience unintended weight loss or vomit blood. Your doctor will ask you about significant lifestyle or diet changes and additional symptoms. A blood panel, urine tests and ultrasound can help diagnose severe nausea.
References
- MedlinePlus; Morning Sickness; Linda J. Vorvick, M.D.; September 2009
- Consumer Reports Health.org; What Are Nausea and Vomiting in Early Pregnancy?; June 2011
- MayoClinic.com; Symptoms of Pregnancy; February 2011
- National Health Service: Causes of Morning Sickness
- MedlinePlus; Hydatidiform Mole; Linda Vorvick, M.D.; November 2010
- FamilyDoctor.org; Morning Sickness; September 2000
