Article Text

Timing of probiotic milk consumption during pregnancy and effects on the incidence of preeclampsia and preterm delivery: a prospective observational cohort study in Norway
  1. Mahsa Nordqvist1,
  2. Bo Jacobsson2,3,
  3. Anne-Lise Brantsæter4,
  4. Ronny Myhre5,
  5. Staffan Nilsson6,
  6. Verena Sengpiel1
  1. 1 Department of Obstetrics and Gynecology, Sahlgrenska University Hospital, Gothenburg, Sweden
  2. 2 Department of Obstetrics and Gynecology, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden
  3. 3 Department of Genetics and Bioinformatics, Domain of Health Data and Digitalisation, Institute of Public Health, Oslo, Norway
  4. 4 Department of Environmental Exposure and Epidemiology, Domain of Infection Control, Environment and Health, Norwegian Institute of Public Health, Oslo, Norway
  5. 5 Department of Genetics and Bioinformatics, Domain of Health Data and Digitalisation, Norwegian Institute of Public Health, Oslo, Norway
  6. 6 Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden
  1. Correspondence to Mahsa Nordqvist; mahsa.nordqvist{at}


Objectives To investigate whether the timing of probiotic milk intake before, during early or late pregnancy influences associations with preeclampsia and preterm delivery.

Design Population based prospective cohort study.

Setting Norway, between 1999 and 2008.

Participants 70 149 singleton pregnancies resulting in live-born babies from the Norwegian Mother and Child Cohort Study (no chronic disease, answered questionnaires, no placenta previa/cerclage/serious malformation of fetus, first enrolment pregnancy). Only nulliparous women (n=37 050) were included in the preeclampsia analysis. Both iatrogenic and spontaneous preterm delivery (between gestational weeks 22+0 and 36+6) with spontaneous term controls (between gestational weeks 39+0 and 40+6) were included in the preterm delivery analysis resulting in 34 458 cases.

Main outcome measures Adjusted OR for preeclampsia and preterm delivery according to consumption of probiotic milk at three different time periods (before pregnancy, during early and late pregnancy).

Results Probiotic milk intake in late pregnancy (but not before or in early pregnancy) was significantly associated with lower preeclampsia risk (adjusted OR: 0.80 (95% CI 0.68 to 0.94) p-value: 0.007). Probiotic intake during early (but not before or during late pregnancy) was significantly associated with lower risk of preterm delivery (adjusted OR: 0.79 (0.64 to 0.97) p-value: 0.03).

Conclusions In this observational study, we found an association between timing of probiotic milk consumption during pregnancy and the incidence of the adverse pregnancy outcomes preeclampsia and preterm delivery. If future randomised controlled trials could establish a causal association between probiotics consumption and reduced risk of preeclampsia and preterm delivery, recommending probiotics would be a promising public health measure to reduce these adverse pregnancy outcomes.

  • Preeclampsia
  • preterm delivery
  • timing of probiotic intake
  • The Norwegian Mother and Child Cohort Study
  • MoBa.

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Supplementary materials


  • Contributors All the authors participated in the planning and conduct of this study and approved the final version. MN, SN and VS analyzed the data. MN, VS, ALB, BJ, RM, SN contributed to interpretation of results and writing the paper. MN wrote the first draft of the manuscript. MN, BJ, VS, ALB, RM, and SN revised several versions of this manuscript. MN is the guarantor.

  • Funding The Norwegian Mother and Child Cohort Study was supported by the Norwegian Ministry of Health and Care Services and the Ministry of Education and Research, NIH/NIEHS (contract no N01-ES-75558), NIH/NINDS (grant no.1 UO1 NS 047537- 01 and grant no.2 UO1 NS 047537-06A1).

  • Competing interests None declared.

  • Ethics approval The present study was conducted according to the guidelines laid down in the Declaration of Helsinki and all procedures involving human subjects were approved by the Regional Committee for Ethics in Medical Research in South-Eastern Norway (S-95113 and S-97045) and the Norwegian Data Inspectorate. This specific project was approved by The Regional Committee for Medical and Health Research Ethics South East (REK/S-06075a (2010/2683)). All MoBa participants provided written informed consent before enrolment into the study.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement No additional data available.