Severe morning sickness may pose long term risks for children

A study by researchers at The University of Auckland’s Liggins Institute and Gravida: National Centre for Growth and Development has revealed that children whose mothers were diagnosed with severe hyperemesis gravidarum (SHG), a severe form of “morning sickness”, may have increased risks of metabolic diseases, such as type 2 diabetes, as adults.

The research, published in the Journal of Clinical Endocrinology and Metabolism, showed that SHG children had a 20% reduction in insulin sensitivity – a measure of the effectiveness of the hormone insulin in managing the body’s blood glucose concentrations.

The researchers assessed development, metabolism and body composition in 36 children aged between four and eleven, whose mothers had had between one and four admissions to hospital for SHG in the first trimester of pregnancy. In 32 cases the condition had persisted throughout pregnancy. The results were compared with data from matched control children of unaffected pregnancies.

Lead investigator Professor Wayne Cutfield said the investigators hypothesised that SHG during early pregnancy exposed the fetus to nutritional stress leading to altered programming of metabolism in postnatal life.
“We were particularly interested in whether there were changes to these children’s body composition and the way they maintained glucose levels,” he said.

Research by Liggins Institute scientists and their collaborators has shown that a child’s nutritional environment during its early stages of development has a critical impact on its long term health.

These effects have been illustrated in survivors of the Dutch Famine which occurred over a clearly defined period during World War ll. Children whose mothers were severely undernourished during their first trimester of pregnancy, were shown to have disturbed glucose metabolism, lipid profiles and cardiovascular disease risk in adulthood.

Prof. Cutfield speculates that there may be similarities between the famine survivors and children exposed to SHG in the way that compromised maternal nutrition in early pregnancy reprogrammes long term food and energy metabolism.

“The reduction we saw in SHG children’s glucose sensitivity is significant,” said Cutfield, “and may put them at risk of developing diseases such as type 2 diabetes later in life.

“However the findings represent a “snap-shot” and need to be corroborated by larger studies. The children in this study should be reassessed in adulthood to identify any long term problems,” he said.

Ayyavoo A, Derraik JGB, Hofman PL, Biggs J, Bloomfield FH, Cormack BE, Stone P, Cutfield WS. Severe hyperemesis gravidarum is associated with reduced insulin sensitivity in the offspring in childhood. J Clin Endocrinol Metab 2013; 98(8):3263-3268.