Study design and participants
The present cross-sectional study forms part of the GEStation and FITness (GESTAFIT) project, the methodology of which has been explained in detail elsewhere14. A total of 384 pregnant women were informed about the study during their first visit to a gynaecologist at the hospital in the 12th week of gestation (w.g.); 159 women who met the inclusion criteria were eventually recruited to the study (Supplementary Table S1) . In adherence to the CONSORT statement15, all provided written, informed consent to be included. The broader GESTAFIT study involved subjects taking part in an exercise program, or following their normal lifestyle, thus requiring the present results be appropriately adjusted (see below).