Pregnancy nausea, commonly known as morning sickness, is a widespread experience in early pregnancy. It causes queasiness and can include vomiting. Despite its name, these symptoms can occur at any time of day or night. Affecting most expectant mothers, it is a recognized early indicator of pregnancy.
When Nausea Typically Begins
Pregnancy nausea often starts around the sixth week of pregnancy, typically two weeks after a missed period. Some individuals may experience symptoms earlier, as early as four weeks. Nausea intensity usually increases, peaking between weeks 8 and 11. For most, these sensations subside by the end of the first trimester, around weeks 12 to 14. However, some women experience symptoms longer, into the second trimester or, rarely, throughout pregnancy.
Variations in Onset and Severity
The experience of pregnancy nausea is not uniform; its onset and severity can differ greatly among individuals. Individual physiological responses and hormonal fluctuations influence when symptoms begin and how intense they become. Some women might experience an earlier or later onset, or their symptoms might be milder or more pronounced. The presence of nausea in previous pregnancies can also impact symptoms in subsequent ones, though each pregnancy remains unique.
What Causes Pregnancy Nausea
Hormonal shifts in early pregnancy are the primary cause of nausea. A rapid increase in human chorionic gonadotropin (hCG), a placental hormone, is strongly implicated. Higher hCG levels correlate with increased nausea severity; for example, twin pregnancies often lead to more intense symptoms due to higher hCG. Elevated estrogen levels, which rise substantially, are also linked to more pronounced nausea. Recent research suggests fetal GDF15, and a mother’s sensitivity to it, also plays a significant role, alongside other factors like blood sugar fluctuations, an increased sense of smell, and changes in gastrointestinal function.
Recognizing Severe Nausea
While mild to moderate pregnancy nausea is common, a severe form known as hyperemesis gravidarum (HG) can occur. HG is characterized by prolonged, severe nausea and vomiting, often leading to dehydration, significant weight loss (5% or more of pre-pregnancy weight), and electrolyte imbalances. Individuals with HG may be unable to keep down food or fluids, feel persistently tired, dizzy, or lightheaded, and have dark, concentrated urine. Seek immediate medical attention if vomiting occurs multiple times daily, is bloody, or if there is persistent abdominal pain or a rapid heart rate. Untreated HG can result in malnourishment for both the mother and the fetus.
Coping Strategies
Managing mild to moderate pregnancy nausea involves simple adjustments to diet and routine. Eat small, frequent meals to prevent an empty stomach, which often worsens nausea. Choose bland, easily digestible foods like crackers, toast, or rice, and avoid greasy, spicy, or strong-smelling foods. Stay hydrated by sipping fluids between meals; ginger products or peppermint may help. Get adequate rest and avoid triggers like certain odors or flickering lights.