Low birth weight or stress during pregnancy can lead to long-term health problems in women, according to a study published today in The Journal of Physiology.

The study found that stress caused by routine physiological tests leads to long-term health complications, affecting adrenal, metabolic and cardio-renal health after pregnancy.

Jean Ni Cheong, from The University of Melbourne, and the PhD student leading the study, said it was known that both stress during pregnancy and being born a female of low birth weight increased the risks of pregnancy complication.

“We know women born with a low birth weight have a higher risk of developing complications while pregnant and stress during pregnancy can also result in pregnancy complications,’’ Ms Cheong said.

“But little is understood about how stress, or a combination of both stress and having been born with a low birth rate affects the mothers for the rest of their lives.’’

Previous research has shown that a low birth weight and stress are very common during pregnancy and can lead to poor health outcomes in children.

Ms Cheong said her research explored what these health issues could also mean to the health of a mother post pregnancy.

“We know stress in pregnancy and low birth rates can complicate pregnancies, but it is unknown if the combination of both these factors together would lead to even more severe outcomes.’’

The researchers used a rat model where restricting oxygen, nutrient and blood supply during pregnancy led to offspring being born with a low birth weight.

When the low birth weight female rats became pregnant, researchers induced stress through common measurements performed during human pregnancy.

Long after the conclusion of pregnancy, they studied parameters in the mothers, including blood pressure, renal function, stress hormone production and performed glucose tolerance testing.

“We found that stress and low birth weight can independently affect cardiovascular, kidney and metabolic health of the mother long after the pregnancy,’’ Ms Cheong said.

“Interestingly, having both risk factors did not exacerbate the effects of one another.”

She said the findings indicated researchers should pay more attention to the role complicated pregnancies have on the health of the women after pregnancy.

“By identifying individuals at higher risk of developing complications during pregnancy and therefore long-term disease, appropriate interventions can be implemented.”

University of Melbourne Professor Mary Wlodek, Professor of Physiology, and lead investigator of the study, said the findings highlight the long-term health implications for women born small or who endured a stressful pregnancy.

“More research is required to further explore why a low birth weight and a stressful pregnancy cause pregnancy complications and adversely harm the health of these mothers,’’ Professor Wlodek said.

“By understanding these pathways, appropriate interventions and advice can be given to women who were born small or had a stressful pregnancy.”