Kwa amayi apakati abwinobwino, pamene msinkhu wa mimba ukukwera, mphamvu ya mtima imawonjezeka ndipo mphamvu ya mtima imachepa. Kawirikawiri amakhulupirira kuti mphamvu ya mtima imayamba kukwera pa masabata 8 mpaka 10 a mimba ndipo imafika pachimake pa masabata 32 mpaka 34 a mimba, kuwonjezeka kwa 30% mpaka 45% poyerekeza ndi omwe alibe mimba, ndipo kumasunga mulingo uwu mpaka kubadwa. Kuchepa kwa mphamvu ya mtima kumachepetsa kuthamanga kwa magazi, ndipo kuthamanga kwa magazi kwa diastolic kumachepa kwambiri, ndipo kusiyana kwa kuthamanga kwa mtima kumakula. Kuyambira masabata 6 mpaka 10 a mimba, kuchuluka kwa magazi kwa amayi apakati kumawonjezeka ndi kuchuluka kwa msinkhu wa mimba, ndipo kumawonjezeka ndi pafupifupi 40% kumapeto kwa mimba, koma kuwonjezeka kwa mphamvu ya plasma kumaposa kwambiri kuchuluka kwa maselo ofiira a magazi, plasma imawonjezeka ndi 40% mpaka 50%, ndipo maselo ofiira a magazi amawonjezeka ndi 10% mpaka 15%. Chifukwa chake, mu mimba yabwinobwino, magazi amachepetsedwa, kumawonekera ngati kuchepa kwa kukhuthala kwa magazi, kuchepa kwa hematocrit, komanso kuchuluka kwa erythrocyte sedimentation rate.

Zinthu zolimbitsa magazi Ⅱ, Ⅴ, VII, Ⅷ, IX, ndi Ⅹ zonse zimawonjezeka panthawi ya mimba, ndipo zimatha kufika nthawi 1.5 mpaka 2.0 kuposa nthawi yachibadwa pakati pa mimba ndi kumapeto kwa mimba, ndipo ntchito za zinthu zolimbitsa magazi Ⅺ ndi  zimachepa. Fibrinopeptide A, fibrinopeptide B, thrombinogen, platelet factor Ⅳ ndi fibrinogen zimawonjezeka kwambiri, pomwe antithrombin Ⅲ ndi protein C ndi protein S zimachepa. Pa nthawi ya mimba, nthawi ya prothrombin ndi nthawi yoyambitsa prothrombin yochepa imafupikitsidwa, ndipo kuchuluka kwa fibrinogen m'magazi kumawonjezeka kwambiri, komwe kumatha kuwonjezeka kufika pa 4-6 g/L mu trimester yachitatu, yomwe ndi yokwera pafupifupi 50% kuposa nthawi yomwe si yapakati. Kuphatikiza apo, plasminogen idawonjezeka, nthawi yosungunuka ya euglobulin idakulitsidwa, ndipo kusintha kwa coagulation-anticoagulation kunapangitsa thupi kukhala lolimba kwambiri, zomwe zinali zothandiza pakuchotsa magazi m'thupi pambuyo pa kusokonekera kwa placenta panthawi yobereka. Kuphatikiza apo, zinthu zina zomwe zimapangitsa kuti magazi azigaya magazi ambiri panthawi ya mimba ndi monga kuchuluka kwa cholesterol yonse, ma phospholipid ndi ma triacylglycerols m'magazi, androgen ndi progesterone zomwe zimatulutsidwa ndi placenta zimachepetsa mphamvu ya zinthu zina zoletsa magazi kugaya magazi, placenta, uterine decidua ndi ma embryos. Kupezeka kwa zinthu za thromboplastin, ndi zina zotero, kungapangitse magazi kukhala mu mkhalidwe wogaya magazi kwambiri, ndipo kusinthaku kumawonjezeka ndi kukula kwa msinkhu wa mimba. Kugaya magazi pang'ono ndi njira yotetezera thupi, yomwe ndi yothandiza kusunga fibrin mu mitsempha yamagazi, khoma la uterine ndi placental villi, kumathandiza kusunga umphumphu wa placenta ndikupanga thrombus chifukwa chochotsa, komanso kuthandizira kutuluka magazi mwachangu panthawi yobereka komanso pambuyo pake. , ndi njira yofunika kwambiri yopewera kutuluka magazi pambuyo pobereka. Nthawi yomweyo yogaya magazi, ntchito yachiwiri ya fibrinolytic imayambanso kuchotsa thrombus mu mitsempha ya uterine spiral ndi venous sinuses ndikufulumizitsa kukonzanso ndi kukonzanso endometrium.