Pregnancy weight linked to nausea

Underweight women have an increased risk of severe nausea and vomiting during pregnancy. Suffering from morning sickness in the early months of pregnancy is common, but in some cases, nausea and vomiting can progress to a condition known as hyperemesis gravidarum. Women with this condition have unrelenting, excessive nausea and vomiting, which makes them vulnerable to malnutrition, dehydration and significant weight loss. This in turn poses risk to the mother and the fetus and may require hospitalisation. To investigate the relation between pregnancy weight and hyperemesis gravidarum, Swiss researchers studied nearly 943,000 women who gave birth between 1992 and 2001. 'Underweight' was defined as a body mass index (BMI- the ratio between height and weight) of less than 20, while obesity was defined as a BMI of 30 or higher. It was found that those who were underweight before pregnancy were 43 percent more likely to get hospitalised for hyperemesis gravidarum than the normal-weight women. In contrast, obese women were found to have a 10 percent decreased risk compared with normal-weight women. Underweight women were also more likely to have taken antiemetics early in pregnancy than normal-weight and obese women. The research pointed out that women might be able to reduce the risk of excessive nausea and vomiting by eating small portions throughout the day, rather than large meals. Taking antiemetic drugs, which prevent vomiting, may also help keep morning sickness from progressing to hyperemesis. Though the cause of hyperemesis gravidarum is still not known, the above findings suggest that pre-pregnancy weight influences the risk of hyperemesis.