Fig. 1

Associations between pre-implantation (n = 125) and post-implantation (n = 121) early pregnancy biomarker concentrations and implantation-based length of gestation. Pre-implantation (white dots) hazard ratios represent the risk of birth for women with pre-implantation measured biomarker concentrations above the median compared with those below the median (reference) and post-implantation (black dots) hazard ratios represent the risk of birth for women with post-implantation measured biomarker concentrations above the median compared with those below the median (reference). Hazard ratios < 1.0, indicate a reduced risk of delivery (i.e., longer gestation) and hazard ratios > 1.0 indicate increased risk of delivery (i.e, shorter gestation)