About the Authors

Tiina Drell

tiinadrell@gmail.com

Affiliations Centre for Biology of Integrated Systems, Tallinn University of Technology, Tallinn, Estonia, Competence Centre on Reproductive Medicine and Biology, Tartu, Estonia

Triin Lillsaar

Affiliations Centre for Biology of Integrated Systems, Tallinn University of Technology, Tallinn, Estonia, Competence Centre on Reproductive Medicine and Biology, Tartu, Estonia

Lea Tummeleht

Current address: Department of Infectious Diseases, Estonian University of Life Sciences, Tartu, Estonia

Affiliation Centre for Biology of Integrated Systems, Tallinn University of Technology, Tallinn, Estonia

Jaak Simm

Affiliation Centre for Biology of Integrated Systems, Tallinn University of Technology, Tallinn, Estonia

Anu Aaspõllu

Affiliation Centre for Biology of Integrated Systems, Tallinn University of Technology, Tallinn, Estonia

Edda Väin

Affiliation Fertilitas Hospital, Haabneeme, Estonia

Ivo Saarma

Affiliation Fertilitas Hospital, Haabneeme, Estonia

Andres Salumets

Affiliations Competence Centre on Reproductive Medicine and Biology, Tartu, Estonia, Department of Obstetrics and Gynaecology, University of Tartu, Tartu, Estonia, Institute of Biomedicine, University of Tartu, Tartu, Estonia

Gilbert G. G. Donders

Affiliations Department Obstetrics and Gynecology, Regional Hospital H Hart, Tienen, Belgium, Femicare vzw, Clinical Research for Women, Tienen, Belgium

Madis Metsis

Affiliations Centre for Biology of Integrated Systems, Tallinn University of Technology, Tallinn, Estonia, Competence Centre on Reproductive Medicine and Biology, Tartu, Estonia

Competing Interests

The study received funding from a commercial source, BiotaP LCC. The company partly financed and provided sequencing service for the project as part of their workflow development for metagenomic sequencing service. This does not alter the authors' adherence to all the PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: TD TL MM. Performed the experiments: TD TL AA. Analyzed the data: LT JS. Contributed reagents/materials/analysis tools: EV IS. Wrote the paper: TD LT GD AS.