A prospective cohort study monitored anti-Xa levels, thromboelastography (TEG) parameters, and coagulation indices in 50 postpartum venous thromboembolism (VTE) patients treated with nadroparin during the first 10 doses. Patients with maximum anti-Xa levels of 0.5–1.0 IU/ml after the 4th dose formed the therapeutic group. TEG parameters showed a biphasic response: R and K peaked after four doses and then declined, while MA, angle and CI had inverse trends. Mean peak anti-Xa levels increased from 0.05 ± 0.08 IU/ml (day 0) to 0.59 ± 0.19 IU/ml (day 5) and correlated positively with R (p = 7.88, p < 0.001) and K (p = 1.45, p = 0.01), negatively with angle (p = -18.38, p < 0.001). 0.001). The treatment group had a shorter hospital stay (7.54 ± 1.72 vs. 9.04 ± 3.14 days, p = 0.044) with no differences in thrombi or adverse events. Nadroparin shows a non-linear dose response and anti-Xa levels with TEG correlations may improve individual anticoagulation monitoring. The study was conducted in Shanghai First Maternity Hospital from September 2021 to July 2022 with a one-year follow-up.