Women whose mothers suffered from severe morning sickness are three times more likely to develop the condition when they become pregnant, new research has found.
A study at the Norwegian Institute of Public Health looked at data on more than two million births between 1967 and 2006.
Researchers found that morning sickness was much more common in women whose mothers had experienced the condition.
The study, which is published in the British Medical Journal, focused on women who experienced nausea and vomiting before the 22nd week of pregnancy - a condition called hyperemesis gravidarum.
'The risk of hyperemesis in a pregnant woman is threefold if the woman's mother had ever experienced hyperemesis in a pregnancy,' the researchers wrote.
'This was regardless of whether hyperemesis had occurred in the pregnancy leading to the woman under study or in a previous or subsequent pregnancy.'
NHS figures suggest that around half of all pregnant women experience both nausea and vomiting during early pregnancy, while 28 per cent suffer from nausea alone.