Pregnant women who take probiotics face increased risk of pre-eclampsia, study suggests

Pregnant women who take probiotic supplements significantly increase their risk of developing the potentially dangerous complication, pre-eclampsia, world-first Queensland research suggests.

Brisbane-based obstetric physician Leonie Callaway, who was involved in the study, said many "mummy bloggers" promoted probiotic tablets or capsules as being "kind of magical in pregnancy", without evidence to prove the benefits.

She said a Queensland review of international studies into the use of probiotic supplements in pregnancy found "a doubling of the risk of pre-eclampsia".

The review was triggered by a Royal Brisbane and Women's Hospital (RBWH) study of more than 400 pregnant women, which found a link between increased rates of high blood pressure and pre-eclampsia in those who took probiotic supplements.

"This was a surprising finding," said Dr Callaway, the RBWH Women's and Newborn Services' director of research.

"It goes to show that natural things we assume to be safe need to be carefully examined for pregnant women. Pregnancy is a special case that requires extra caution.

Further research on the connection between probiotic supplementation and pre-eclampsia is planned.

Dr Callaway said there was no suggestion low-dose probiotics found in yoghurts, sauerkraut, kombucha and kimchi products increased pre-eclampsia in pregnant women.

"The best medicine for pregnancy is a nutritious diet, regular physical activity, plenty of sleep, sunshine, a generally healthy lifestyle," she said.

The professor of medicine at the University of Queensland, described pre-eclampsia as one of the most serious complications of pregnancy, describing it as a common reason for women to give birth prematurely or to a low birth weight baby.

"It's associated with higher blood pressure and with the kidneys not working properly, such that they leak protein out into the urine," she said.

"It's a condition that affects every part of the body – it causes trouble with the liver, with the blood vessels, with the brain and heart.

"It affects the placenta … which is why babies being born to mothers with pre-eclampsia can be very, very tiny."

Dr Callaway, co-chair of the Queensland Maternal and Perinatal Quality Council, said pre-eclampsia affected about 4 per cent of all pregnancies.

Symptoms of pre-eclampsia include severe headaches, blurry vision, severe abdominal pain and shortness of breath.

Obstetrician Gino Pecoraro, who was not involved in the research, said based on the findings, he would discourage pregnant women from taking probiotic supplements.

"The moral of the story is when you're pregnant, don't take any faddish things. It may actually do harm," Dr Pecoraro said.

"We found the same thing with fish oil tablets. Eating fish decreased the risk of pre-eclampsia but taking fish oil capsules for some reason didn't and in fact, may have made things worse."

Dr Pecoraro said taking folic acid in pregnancy had been conclusively found to decrease the risk of neural tube defects in babies and women were also recommended to take a pregnancy supplement that included iodine.

The RBWH Foundation and the National Health and Medical Research Council funded Dr Callaway's research.