[Comparison of four-coagulation-tests values in normal pregnant women during early and late pregnancy and the influence of age].

Objective: To explore and compare the reference ranges of four coagulation tests in normal pregnant women during early and late pregnancy and the influence of age. Methods: Values of four coagulation tests from 4 974 pregnant women, who gave single birth at Peking University First Hospital, Obstetrics and Gynecology Hospital of Fudan University, West China Second University Hospital, Peking University Third Hospital and Shengjing Hospital of China Medical University from February 2017 to July 2020, were measured and analyzed in this study, including prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fib) and thrombin time (TT). The four normal reference ranges of coagulation during early and late pregnancy phases were expressed as P2.5-P97.5. The difference of two pregnancy phases was compared by non-parametric test of two related samples. And the difference between pregnant women of advanced and non-advanced age in the same pregnancy phase was compared by independent sample non-parametric test. Chi-square test was used to compare the incidence of pregnancy complications in different coagulation reference ranges. Results: The reference ranges of PT of normal pregnant women's early and late pregnancy were 10.0-13.9 s and 9.6-12.3 s, the reference ranges of APTT were 22.6-35.3 s and 22.4-30.9 s, the reference ranges of Fib were 2.4-5.0 g/L and 3.0-5.7 g/L, the reference ranges of TT were 12.0-19.0 s and 11.5-18.4 s. Compared with early pregnancy, PT, APTT and TT shortened significantly, while the Fib significantly increased in late pregnancy (all P<0.001). PT, APTT and TT of advanced and non-advanced age pregnant women were significantly different (all P<0.01). Compared with the ranges of non-pregnant population, more pregnant women were included in the normal pregnant reference ranges of PT in early pregnancy and APTT in the early and late pregnancy, while the incidence of pregnancy complications had no significant differences (all P>0.05). The incidence of fetal distress was higher and the incidence of preterm birth was lower in the reference range of PT in late pregnancy. The incidence of gestational diabetes mellitus was higher in the early and late gestational Fib reference ranges, and the incidence of hypertensive disorders in pregnancy was higher in the late gestational Fib reference range (all P<0.05). Conclusions: The coagulation function of pregnant women increases significantly with the growth of pregnancy, and there is a significant difference between advanced significantly and non-advanced age pregnant women. The recommended ranges of normal pregnant women's early and late pregnancy PT are 10.0-13.9 s and 9.6-12.3 s, the recommended ranges of APTT are 22.6-35.3 s and 22.4-30.9 s, the recommended ranges of TT are 12.0-19.0 s and 11.5-18.4 s. The appropriate ranges of normal pregnant women's early and late pregnancy Fib still need further exploration.目的： 探讨正常孕妇妊娠早期、妊娠晚期凝血四项的参考值范围，并分析年龄对其影响。 方法： 收集并分析2017年2月至2020年7月于北京大学第一医院、复旦大学附属妇产科医院、四川大学华西第二医院、北京大学第三医院和中国医科大学附属盛京医院单胎分娩的4 974例孕妇妊娠早期、妊娠晚期的凝血四项检查结果，包括凝血酶原时间（PT）、活化部分凝血活酶时间（APTT）、纤维蛋白原（Fib）及凝血酶时间（TT）。以其中2 322例无并发症的正常孕妇妊娠早期、妊娠晚期凝血四项检查结果的第2.5~97.5百分位数为本研究的参考值范围，分析高龄对其影响，比较此参考值范围与正常非孕妇女正常值的差异，分析相应范围妊娠并发症的发生率。 结果： 2 322例无并发症孕妇妊娠早期、妊娠晚期的PT参考值范围分别为10.0~13.9、9.6~12.3 s，APTT参考值范围分别为22.6~35.3、22.4~30.9 s，Fib参考值范围分别为2.4~5.0、3.0~5.7 g/L，TT参考值范围分别为12.0~19.0、11.5~18.4 s。与妊娠早期比较，妊娠晚期PT、APTT和TT显著缩短，而Fib显著升高（P均<0.001）。2 322例正常孕妇中，非高龄孕妇妊娠早期PT、APTT及妊娠晚期APTT均长于高龄孕妇；其妊娠早期TT及妊娠晚期PT、TT均短于高龄孕妇；分别比较，差异均有统计学意义（P均<0.01）。4 974例孕妇中，与非孕妇女正常值范围纳入的孕妇相比，本研究妊娠早期PT、妊娠早期和妊娠晚期APTT的参考值范围纳入的孕妇例数更多，而妊娠并发症的发生率无显著差异（P均>0.05）；妊娠晚期PT参考值范围内胎儿窘迫的发生率更高而早产发生率较低；妊娠早期Fib参考值范围内的孕妇妊娠期糖尿病发生率较高，妊娠晚期Fib参考值范围内的孕妇妊娠期糖尿病、妊娠期高血压疾病的发生率均较高（P均<0.05）。 结论： 孕妇凝血功能随着孕周增长显著增强，且高龄和非高龄孕妇间存在显著差异。正常孕妇妊娠早期、妊娠晚期PT参考值范围分别为10.0~13.9、9.6~12.3 s；APTT参考值范围分别为22.6~35.3、22.4~30.9 s；TT参考值范围分别为12.0~19.0、11.5~18.4 s；Fib的参考值范围还有待进一步研究。.