The study used data about diet and a number of other factors from more than 33 000 first-time mothers who participated in the Norwegian Mother and Child Cohort Study (MoBa) at the NIPH.
Too early to comment on causation
The study shows that the incidence of pre-eclampsia was lowest in those who consumed probiotic dairy products equivalent to a glass of probiotic milk or probiotic yoghurt daily.
“The results are exciting for further research and suggest the possibility of an entirely new direction in the prevention of pre-eclampsia and other diseases in pregnancy. However, it is important to note that this relationship must be confirmed by randomised controlled studies before we can say that probiotics actually protect against pre-eclampsia,” says researcher Ronny Myhre at the NIPH.
The results correspond with other studies which have found an association between the use of probiotics and lower blood pressure, and between probiotics and inflammatory reactions in the intestine. Elevated blood pressure is a cardinal symptom of pre-eclampsia.
What should pregnant women do?
The Norwegian Directorate of Health's advice about diet during pregnancy includes a daily intake of milk and dairy products because they provide many essential nutrients.
Based on this study, it is too early to recommend that pregnant women should consume probiotic milk products. More studies to support the findings and identify any potential adverse effects are required.
About the study
This population study is part of the Norwegian Mother and Child Cohort Study at the Norwegian Institute of Public Health.
The study used data about diet and other factors for 33 399 first-time mothers. Among these 1,755 (5.3 per cent) developed pre-eclampsia. Pre-eclampsia is a condition that can become dangerous for the mother and the unborn child. The condition is characterised by elevated blood pressure and protein in the urine.
The study shows only a statistical association between intake of probiotic milk products and a lower incidence of pre-eclampsia. To find out more about the causal relationship, a study of a random sample of pregnant women is required where half would drink a probiotic milk product and the other half would drink a milk product without these bacteria. Even if a beneficial effect was found, all cases of pre-eclampsia would not necessarily be prevented with the consumption of probiotic milk products.
Probiotics are a special type of live bacteria, usually lactic acid bacteria, a natural inhabitant of the intestines. In this study, the probiotics were bifido and lactic acid bacteria with an assumed beneficial effect to health.
Intake of Probiotic Food and Risk of Preeclampsia in Primiparous Women, The Norwegian Mother and Child Cohort Study, Brantsæter AL, Myhre R, Haugen M, Myking S, Sengpiel V, Magnus P, Jacobsson B and Meltzer HM (2011) Am J Epidemiol. 174(7):807-15.