Miscarriage is a pregnancy loss before 20 gestational weeks. Preterm birth (PTB), a birth before 37 gestational weeks, causes a high rate of perinatal morbidity and mortality. Despite the threats, there is a lack of diagnostic biomarker that can identify PTB or miscarriage in the early stage of pregnancy. The goal of this project is to discover of PTB and miscarriage metabolic markers in urine or serum by partial deuterium oxide (D2O) labeling for developing an early diagnostic tool. The technique, “Deuterium Oxide (D2O) Labeling for Global Omics Relative Quantification (DOLGOReQ)” was performed in search for PTB or miscarriage markers.