Mu amayi oyembekezera abwinobwino, ndi kukula kwa gestational zaka, linanena bungwe mtima kumawonjezeka ndi zotumphukira kukana amachepetsa.Ambiri amakhulupirira kuti kutulutsa kwa mtima kumayamba kuwonjezeka pa masabata 8 mpaka 10 a mimba ndipo kufika pachimake pa masabata 32 mpaka 34 a bere, kuwonjezeka kwa 30% mpaka 45% poyerekeza ndi omwe alibe mimba, ndipo amasunga mlingo umenewu mpaka kubereka.Kutsika kwa zotumphukira mtima kukana kumachepetsa kuthamanga kwa magazi, ndipo kuthamanga kwa magazi kwa diastolic kumachepa kwambiri, ndipo kusiyana kwa kugunda kwa mtima kumakulirakulira.Kuyambira masabata 6 mpaka 10 a bere, kuchuluka kwa magazi kwa amayi apakati kumawonjezeka ndi kuwonjezeka kwa msinkhu, ndipo kumawonjezeka pafupifupi 40% kumapeto kwa mimba, koma kuwonjezeka kwa madzi a m'magazi kumaposa chiwerengero cha maselo ofiira a m'magazi, plasma. imawonjezeka ndi 40% mpaka 50%, ndipo maselo ofiira amawonjezeka ndi 10% mpaka 15%.Choncho, mu yachibadwa mimba, magazi kuchepetsedwa, anasonyeza ngati utachepa kukhuthala kwa magazi, utachepa hematocrit, ndi kuchuluka erythrocyte sedimentation mlingo .

Magazi a coagulation factor Ⅱ, Ⅴ, VII, Ⅷ, IX, ndi Ⅹ onse amawonjezeka pa nthawi ya mimba, ndipo amatha kufika 1.5 mpaka 2.0 nthawi zachilendo pakati ndi mochedwa mimba, ndi ntchito za coagulation factor Ⅺ ndi  kuchepa.Fibrinopeptide A, fibrinopeptide B, thrombinogen, platelet factor Ⅳ ndi fibrinogen zinawonjezeka kwambiri, pamene antithrombin Ⅲ ndi mapuloteni C ndi mapuloteni S anachepa.Pa nthawi ya mimba, nthawi ya prothrombin ndi nthawi yowonjezera ya prothrombin imafupikitsidwa, ndipo plasma fibrinogen zomwe zili mu plasma zimawonjezeka kwambiri, zomwe zingathe kuwonjezeka kufika 4-6 g/L mu trimester yachitatu, yomwe ili pafupifupi 50% kuposa ya omwe alibe. nthawi.Kuonjezera apo, plasminogen inawonjezeka, nthawi ya kusungunuka kwa euglobulin inali yaitali, ndipo kusintha kwa coagulation-anticoagulation kunapangitsa kuti thupi likhale la hypercoagulable state, zomwe zinali zopindulitsa ku hemostasis yogwira mtima pambuyo pa kutuluka kwa placenta panthawi yobereka.Komanso, zinthu zina hypercoagulable pa mimba monga kuchuluka kwa mafuta m`thupi okwana, phospholipids ndi triacylglycerols m`mwazi, androgen ndi progesterone opangidwa ndi latuluka amachepetsa zotsatira za magazi coagulation inhibitors, latuluka, uterine decidua ndi miluza.Kukhalapo kwa zinthu za thromboplastin, ndi zina zotero, kungapangitse magazi kukhala mu hypercoagulable state, ndipo kusintha kumeneku kumawonjezereka ndi kuwonjezeka kwa msinkhu wa gestational.Moderate hypercoagulation ndi njira yotetezera thupi, yomwe imakhala yopindulitsa kusunga fibrin m'mitsempha, khoma la chiberekero ndi placenta villi, kuthandizira kusunga umphumphu wa placenta ndikupanga thrombus chifukwa cha kuvula, ndikuthandizira kuthamanga kwa magazi panthawi ndi pambuyo pobereka., ndi njira yofunika kwambiri yopewera kutaya magazi pambuyo pobereka.Pa nthawi yomweyo coagulation, sekondale fibrinolytic ntchito akuyambanso kuchotsa thrombus mu uterine ozungulira mitsempha ndi venous nkusani ndi imathandizira kusinthika ndi kukonza endometrium .