Fig. 2. Labor progress population models present individual measurements (vertical bars ) and model prediction (red squares ). Time is presented as hours before full cervical dilation. (A ) Initial progress model without covariates. (B ) Final genetic optimization model incorporating covariate effects. Predictors include genotype at β2AR27, maternal weight, and presence of neuraxial analgesia. (C ) Final ethnicity optimization model incorporating covariate effects. Predictors include ethnicity and neuraxial analgesia.