| aging | Residual DNA-methylation-based (DNAm) gestational age |
| beta_v_indices | Indices for random beta values |
| bmiq_norm_450k | Normalize DNA methylation values |
| download_beta_values_case | Access Beta values at individual CpG sites for case group |
| download_beta_values_control | Access Beta values at individual CpG sites for control group |
| ga | Gestational age for both case and control groups |
| ipla | Identify placental aging |
| phenotype | Phenotype for both case and control groups |
| plec | Estimate DNA-methylation-based gestational age |
| plec_int_coef | Intercept and coefficients of placental epigenetic clock |
| plec_scaler_mean | Mean values of the scalers of placental epigenetic clock |
| plec_scaler_scale | Scale values of the scalers of placental epigenetic clock |
| probe_info_450k | Probe info for 450K |
| qc | Perform quality control |