Kukukhulelwa okuqhelekileyo, umlinganiselo wentliziyo uyanda kwaye ukumelana nomzimba uyancipha xa ukhulelwe. Ngokuqhelekileyo kukholelwa ukuba umlinganiselo wentliziyo uqala ukwanda kwiiveki ezisi-8 ukuya kwezili-10 zokukhulelwa, kwaye ufikelela kwincopho kwiiveki ezingama-32 ukuya kwezingama-34 zokukhulelwa, okungaphezulu ngama-30% ukuya kuma-45% kunaxa ungakhulelwanga, kwaye kugcina eli nqanaba de kube kuzelwe. Ukwehla kokumelana nomzimba emzimbeni kunciphisa uxinzelelo lwemithambo yegazi, kwaye uxinzelelo lwegazi lwe-diastolic luyancipha kakhulu, kwaye umahluko woxinzelelo lwe-pulse uyanda. Ukusuka kwiiveki ezi-6 ukuya kwezili-10 zokukhulelwa, umthamo wegazi wabasetyhini abakhulelweyo uyanda ngokunyuka kweminyaka yokukhulelwa, kwaye unyuka malunga nama-40% ekupheleni kokukhulelwa, kodwa ukwanda komthamo weplasma kudlula kakhulu inani leeseli ezibomvu zegazi, iplasma inyuka ngama-40% ukuya kuma-50%, kwaye iiseli ezibomvu zegazi zinyuka nge-10% ukuya kwi-15%. Ke ngoko, kukukhulelwa okuqhelekileyo, igazi liyancitshiswa, libonakala njengokuncipha kwe-viscosity yegazi, ukwehla kwe-hematocrit, kunye nokwanda kwesantya se-erythrocyte sedimentation [1].

Izinto ezibangela ukujiya kwegazi Ⅱ, Ⅴ, VII, Ⅷ, IX, kunye Ⅹ zonke ziyanda ngexesha lokukhulelwa, kwaye zinokufikelela kwi-1.5 ukuya kwi-2.0 amaxesha aqhelekileyo phakathi kokukhulelwa kunye nokugqibela, kwaye imisebenzi yezinto ezibangela ukujiya Ⅺ kunye  iyancipha. I-Fibrinopeptide A, i-fibrinopeptide B, i-thrombinogen, i-platelet factor Ⅳ kunye ne-fibrinogen zanda kakhulu, ngelixa i-antithrombin Ⅲ kunye neproteni C kunye neproteni S zehla. Ngexesha lokukhulelwa, ixesha le-prothrombin kunye nexesha le-prothrombin elisebenzayo elingasebenziyo liyafinyezwa, kwaye umxholo we-plasma fibrinogen uyanda kakhulu, onokunyuka uye kwi-4-6 g/L kwi-trimester yesithathu, engaphezulu ngama-50% kunaleyo kwixesha elingakhulelwanga. Ukongeza, i-plasminogen yanda, ixesha lokuchithwa kwe-euglobulin landiswa, kwaye utshintsho lwe-coagulation-anticoagulation lwenze umzimba ube kwimeko yokujiya kakhulu, eyayiluncedo kwi-hemostasis esebenzayo emva kokuphazamiseka kwe-placenta ngexesha lokubeletha. Ukongeza, ezinye izinto ezibangela ukubola kwegazi ngexesha lokukhulelwa ziquka ukunyuka kwe-cholesterol iyonke, ii-phospholipids kunye nee-triacylglycerols egazini, i-androgen kunye ne-progesterone ekhutshwa yi-placenta inciphisa impembelelo yezinye izithinteli zokubola kwegazi, i-placenta, i-uterine decidua kunye nee-embryos. Ubukho bezinto ezibangela i-thromboplastin, njl.njl., bunokukhuthaza igazi ukuba libe kwimeko yokubola kwegazi, kwaye olu tshintsho luba mandundu xa ixesha lokukhulelwa lisanda. I-hypercoagulation ephakathi yindlela yokukhusela yomzimba, eluncedo ekugcineni i-fibrin ifakwa kwimithambo yegazi, udonga lwesibeleko kunye ne-placental villi, inceda ukugcina ukuthembeka kwe-placenta kunye nokwenza i-thrombus ngenxa yokukrazula, kwaye iququzelele i-hemostasis ekhawulezayo ngexesha nasemva kokubeleka. , yindlela ebalulekileyo yokuthintela ukopha kwegazi emva kokubeletha. Ngexesha elifanayo lokubola kwegazi, umsebenzi wesibini we-fibrinolytic uphinda uqale ukususa i-thrombus kwimithambo yegazi ye-uterine kunye ne-venous sinuses kwaye ukhawulezise ukuvuselelwa nokulungiswa kwe-endometrium [2].

Nangona kunjalo, imeko yokubola kakhulu kwegazi inokubangela iingxaki ezininzi zokubeleka. Kwiminyaka yakutshanje, uphando lufumanise ukuba abafazi abaninzi abakhulelweyo bathambekele kwi-thrombosis. Le meko yesifo se-thromboembolism kubafazi abakhulelweyo ngenxa yeziphene zemfuza okanye izinto ezinobungozi ezifana neeproteni ze-anticoagulant, izinto ezibangela ukubola kwegazi, kunye neeproteni ze-fibrinolytic ibizwa ngokuba yi-thrombosis. (thrombophilia), eyaziwa ngokuba yi-prothrombotic state. Le meko yokubola kwegazi ayikhokeleli kwisifo se-thrombotic, kodwa inokukhokelela kwiziphumo ezimbi zokukhulelwa ngenxa yokungalingani kwindlela yokubola kwegazi-i-anticoagulation okanye umsebenzi we-fibrinolytic, i-microthrombosis yemithambo ye-spiral yesibeleko okanye i-villus, okubangela ukuvuza kakuhle kwe-placental okanye nokuba yi-infarction, njenge-Preeclampsia, i-placental abruption, i-placental infarction, i-disseminated intravascular coagulation (DIC), ukuthintelwa kokukhula kwe-fetal, ukuphuphuma kwesisu okuphindaphindiweyo, ukuzalwa kwengane esele ifile kunye nokuzalwa ngaphambi kwexesha, njl.njl., kunokukhokelela ekufeni komama nakwi-perinatal kwiimeko ezinzima.