Rau cov poj niam cev xeeb tub ib txwm, thaum lub hnub nyoog cev xeeb tub nce ntxiv, lub plawv tso zis ntau ntxiv thiab kev tiv thaiv ntawm cov hlab ntsha txo qis. Feem ntau ntseeg tias lub plawv tso zis pib nce ntxiv thaum 8 txog 10 lub lis piam ntawm kev cev xeeb tub thiab ncav cuag qhov siab tshaj plaws thaum 32 txog 34 lub lis piam ntawm kev cev xeeb tub, nce ntxiv 30% txog 45% piv rau cov neeg tsis cev xeeb tub, thiab tswj qib no kom txog thaum yug menyuam. Qhov txo qis ntawm kev tiv thaiv ntawm cov hlab ntsha hauv cov hlab ntsha txo qis lub siab ntawm cov hlab ntsha, thiab lub siab ntawm cov ntshav diastolic txo qis heev, thiab qhov sib txawv ntawm lub zog ntawm lub plawv dhia dav dua. Txij li 6 txog 10 lub lis piam ntawm kev cev xeeb tub, cov ntshav ntim ntawm cov poj niam cev xeeb tub nce ntxiv thaum lub hnub nyoog cev xeeb tub nce ntxiv, thiab nce li ntawm 40% thaum kawg ntawm kev cev xeeb tub, tab sis qhov nce ntawm cov ntshav hauv cov ntshav ntau dua li cov qe ntshav liab, cov ntshav hauv cov ntshav nce ntxiv 40% txog 50%, thiab cov qe ntshav liab nce ntxiv 10% txog 15%. Yog li ntawd, thaum cev xeeb tub ib txwm, cov ntshav raug diluted, qhia tau tias cov ntshav viscosity txo qis, hematocrit txo qis, thiab erythrocyte sedimentation rate nce ntxiv.

Cov yam ntxwv ntshav coagulation Ⅱ, Ⅴ, VII, Ⅷ, IX, thiab Ⅹ txhua yam nce ntxiv thaum cev xeeb tub, thiab tuaj yeem ncav cuag 1.5 txog 2.0 npaug ntawm qhov ib txwm muaj thaum cev xeeb tub nruab nrab thiab lig, thiab cov haujlwm ntawm cov yam ntxwv coagulation Ⅺ thiab  txo qis. Fibrinopeptide A, fibrinopeptide B, thrombinogen, platelet factor Ⅳ thiab fibrinogen nce ntxiv ntau, thaum antithrombin Ⅲ thiab protein C thiab protein S txo qis. Thaum cev xeeb tub, lub sijhawm prothrombin thiab lub sijhawm ua haujlwm ib nrab prothrombin raug luv dua, thiab cov ntsiab lus plasma fibrinogen nce ntxiv ntau, uas tuaj yeem nce mus txog 4-6 g / L hauv peb lub hlis thib peb, uas yog kwv yees li 50% siab dua li thaum tsis cev xeeb tub. Tsis tas li ntawd, plasminogen nce ntxiv, lub sijhawm euglobulin yaj tau ntev dua, thiab kev hloov pauv coagulation-anticoagulation ua rau lub cev nyob rau hauv lub xeev hypercoagulable, uas tau txais txiaj ntsig zoo rau kev hemostasis tom qab placental abruption thaum lub sijhawm yug menyuam. Ntxiv rau, lwm yam hypercoagulable thaum cev xeeb tub suav nrog kev nce ntawm tag nrho cov cholesterol, phospholipids thiab triacylglycerols hauv cov ntshav, androgen thiab progesterone secreted los ntawm placenta txo cov nyhuv ntawm qee cov ntshav coagulation inhibitors, placenta, uterine decidua thiab embryos. Qhov muaj cov tshuaj thromboplastin, thiab lwm yam, tuaj yeem txhawb cov ntshav kom nyob rau hauv lub xeev hypercoagulable, thiab qhov kev hloov pauv no yog exacerbated nrog kev nce ntawm lub hnub nyoog gestational. Medium hypercoagulation yog ib qho kev ntsuas tiv thaiv physiological, uas yog pab txhawb kom fibrin deposition hauv cov hlab ntsha, phab ntsa uterine thiab placental villi, pab tswj kev ncaj ncees ntawm placenta thiab tsim thrombus vim stripping, thiab pab txhawb kom sai hemostasis thaum thiab tom qab yug menyuam. , yog ib qho tseem ceeb mechanism los tiv thaiv postpartum hemorrhage. Tib lub sijhawm ntawm coagulation, theem nrab fibrinolytic kev ua ub no kuj pib tshem tawm cov thrombus hauv uterine spiral arteries thiab venous sinuses thiab ua kom nrawm dua kev rov ua dua thiab kho ntawm endometrium.