Nausea and vomiting are linked to increased hormone production in early pregnancy. Symptoms usually begin between the fifth and sixth week after the first day of the last menstrual period, and can range from mild heartburn to violent vomiting. The symptoms usually clear up by the 13th week of pregnancy but in some cases it can continue until delivery.

Heartburn, nausea and vomiting during early pregnancy are common and affect up to 80 per cent of all pregnant women. However, some women experience prolonged and severe vomiting called hyperemesis gravidarum, which can pose risks to the health of both mother and baby. Excessive vomiting can result in malnutrition and dehydration with dangerous shifts in the electrolyte levels (chemistry) in the blood. Another serious potential complication is bleeding in the retina of the eye (hemorrhagic retinitis) caused by increased blood pressure during vomiting.

Because hyperemesis gravidarum can be life threatening to the woman and her baby, she may be hospitalised and given electrolytes and drugs via an intravenous drip. Once dehydration and vomiting have been corrected, she can begin eating frequent, small portions of bland foods.

Easing nausea

In mild cases of morning sickness, several steps can be taken to ease the symptoms:

• Eat frequent, small meals that are high in carbohydrates. Have a snack as often as every two hours
• Avoid greasy, spicy or strong smelling foods and drinks
• Limit your intake of sweet foods, which seem to worsen nausea in many women
• Try eating breakfast before getting out of bed in the morning. Many women find that bland, dry biscuits or ginger biscuits eaten first thing in the morning relieve their nausea
• Avoid drinking beverages with your meals
• Ginger is a safe method of easing nausea. Try sipping ginger tea or ginger ale throughout the day, or nibbling on crystallised ginger when you feel nauseous
• Consider liquid meals such as nutrient-enriched diet shakes, if you cannot tolerate solid foods
• Your doctor may prescribe medications for nausea but there remains some doubt about the safety of some of these medications

The good news is that morning sickness generally clears up by the second trimester, when a hearty appetite is likely to replace your earlier aversion to foods.