Extreme nausea and vomiting varies among pregnant women from different countries

April 25, 2008

Mothers born in India and Sri Lanka are three times more likely to suffer from extreme nausea and vomiting in pregnancy (hyperemesis gravidarum) than ethnic Norwegians. This finding comes from the Norwegian Institute of Public Health’s study of 900, 000 first-time pregnancies registered in the Medical Birth Registry of Norway over a forty year period.

Earlier studies reported that 90 percent of pregnant women experience some degree of nausea and vomiting, whereas 0.5 to 2 percent have hyperemesis gravidarum. Due to dehydration, loss of important electrolytes, malnutrition and weight loss, hyperemesis gravidarum could be life-threatening for mother and baby if left untreated. In the USA it is the commonest cause for hospitalisation during early pregnancy. The cause of hyperemesis gravidarum is unknown.

Åse Vikanes, specialist in gynaecology and obstetrics at the institute’s Division of Epidemiology, wanted to explore whether the mothers’ country of birth affected the prevalence of hyperemesis gravidarum. Vikanes is primary author of the paper “Variations in prevalence of hyperemesis gravidarum by country of birth: A study of 900, 074 pregnancies in Norway, 1967-2005.”

Large study on hyperemesis gravidarum

Vikanes and her colleagues collected data from the Medical Birth Registry of Norway, which since 1967 has recorded data on all pregnancies and pregnancy complications. 8, 300 cases of hyperemesis gravidarum were recorded out of 900, 000 pregnancies, giving an overall prevalence of 0.89 percent. Data on the mother’s country of birth and education were recorded by Statistics Norway and linked to pregnancy information through the mother’s unique personal identification number. Socio-demographic factors such as marital status, country of birth, education, age and number of foetuses in each pregnancy were also studied.

“This is one of the largest studies carried out on hyperemesis gravidarum. In contrast to earlier studies we tested the quality of the data and therefore have confidence in our findings” says Vikanes.

Mothers born in India and Sri Lanka had the highest prevalence of hyperemesis gravidarum, followed by those born in Africa (excluding North Africa) and Pakistan by 3.2 percent, 3.1 percent and 2.1 percent, respectively. Ethnic Norwegians, North Americans and Western Europeans had the lowest prevalence by 0.9 percent, 0.9 percent and 0.8 percent, respectively. A maternal age between 20-24 years old, being married, carrying a female foetus or more than one foetus were all socio-demographic characteristics associated with a higher prevalence of hyperemesis gravidarum.

Need to study further

“The difference in prevalence of hyperemesis gravidarum related to the mother’s country of birth cannot be explained by differences in socio-demographic characteristics”, says Vikanes. “We have to look for other explanations such as genetic factors, a change of diet or a history of infections. This topic needs further research to identify ways to prevent this life-threatening and distressing condition.”

Source: Norwegian Institute of Public Health

Explore further: Study shows extreme form of pregnancy-related morning sickness could be genetic

Related Stories

Recommended for you

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

(PhysOrg.com) -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...

Quantum Theory May Explain Wishful Thinking

April 14, 2009

(PhysOrg.com) -- Humans don’t always make the most rational decisions. As studies have shown, even when logic and reasoning point in one direction, sometimes we chose the opposite route, motivated by personal bias or simply ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

THEY
not rated yet Apr 25, 2008
Hyperemesis gravidarum is very severe for both mother and baby in numerous ways. My sister in law had that through her entire pregnancy, and her baby was diagnosed with liver cancer at 5 months old. At 13 months old she is still fighting for her life, all due to the severe malnutrition when she was in the womb.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.