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Establishment of trimester-specific reference intervals for hemostatic and hematologic indices and their associations
Huimin Shi1, Jiayi Chen1, Junwei Liu1
1Fujian Maternity and Child Health Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou 350001, China; Department of Epidemiology and Health Statistics, School of Public Health, Fujian Medical University, Fuzhou 350001, China.
Background:
We established trimester-specific reference intervals (TSRIs) for hemostatic and hematologic indices in singleton pregnancy and evaluated their abnormalities in relation to adverse pregnancy outcomes (APOs; defined in Section 2.4).
Methods:
This single-center prospective cohort study at Fujian Maternity and Child Health Hospital in southeastern China included 16,923 singleton pregnancies (97.8% Han Chinese; ChiCTR2200055116). Nine indices were measured: fibrinogen (FIB), prothrombin time (PT), prothrombin activity (PTA), activated partial thromboplastin time (APTT), thrombin time (TT), D-dimer, fibrinogen degradation products (FDP), platelet count (PLT), and hemoglobin (HGB). These indices were measured at four predefined stages (9-12, 22-26, and 30-34 weeks, and within 3 days before delivery) using an STA-R Max coagulation analyzer and a BC-7500 hematology analyzer. TSRIs were established using inverse modeling (primary method), truncated maximum likelihood (TML), and Hoffmann methods, and associations between abnormalities defined by these TSRIs and APOs were evaluated.
Results:
Inverse modeling defined TSRIs for T1, T2, T3, and delivery as follows: FIB, 2.70-4.76, 2.81-5.46, 3.15-5.60, and 3.09-5.77 g/L; PT, 9.8-12.0, 9.8-11.7, 9.8-11.9, and 9.8-11.5 s; PTA, 87.7-115.3, 89.9-120.1, 89.9-117.5, and 92.2-120.8%; APTT, 22.4-30.2, 21.9-29.6, 21.4-29.9, and 21.6-30.8 s; TT, 14.7-16.8, 14.4-16.5, 14.4-16.5, and 14.6-16.7 s; D-dimer, 0.14-0.70, 0.26-1.97, 0.56-3.07, and 0.65-3.51 mg/L; FDP, 0.57-4.00, 1.12-7.92, 2.13-11.40, and 3.50-12.92 μg/mL; PLT, 159-349, 143-319, 133-324, and 122-308 × 10^9/L; HGB, 111-144, 100-132, 99-137, and 103-144 g/L. TSRI-defined abnormalities in FIB, APTT, D-dimer, FDP, and HGB were associated with higher risks of preterm birth, low birth weight, macrosomia, and postpartum hemorrhage.
Conclusion:
We recommend using TSRIs to assess hemostatic and hematologic indices in pregnancy to enable earlier detection and reduce APO risk.
