Doutremepuich C, Fantauzzi B, Masse A, Refauvelet J, Bousquet F, Toulemonde F, Quilichini R
Pathol Biol (Paris). 1985 Jun;33(6):677-9.
Because of a further clinical use of low-molecular weight heparin fraction in prevention or treatment of venous thrombo-embolism, it was necessary to establish whether they cross the placenta. The studies were performed in pregnant rabbits. High doses of commercial unfractionated heparin (1 000 and 1 600 anti-Xa units per kg of body-weight) and high doses of a low molecular weight heparin fraction (1 000; 8 000 and 16 000 anti-Xa units per kg of body weight) were injected to animals at the end of gestation (term: 30 days). The placenta crossing was studied by drawing blood samples from the mother and foetus for assays of heparin blood level. There is no detectable levels of heparin in the foetus at any time after injection of commercial heparin at the dose of 1 000 anti-Xa units per kg; meanwhile heparin blood level is very low at the dose of 16 000 anti-Xa units/kg. The low molecular weight heparin fraction do not cross the placenta at the dose of 1 000 anti-Xa units/kg. However for higher doses (8 000 and 16 000 anti-Xa/kg) this heparin fraction gives a foetal heparin blood level upper than the one given by commercial heparin.
由于低分子量肝素片段在预防或治疗静脉血栓栓塞方面有进一步的临床应用，因此有必要确定它们是否会穿过胎盘。研究在怀孕的兔子身上进行。在妊娠末期（孕期：30天）给动物注射高剂量的市售普通肝素（每千克体重1000和1600抗Xa单位）和高剂量的低分子量肝素片段（每千克体重1000；8000和16000抗Xa单位）。通过采集母体和胎儿的血样来检测肝素血水平，从而研究胎盘的通透性。在以每千克1000抗Xa单位的剂量注射市售肝素后的任何时候，胎儿体内均未检测到肝素水平；同时，在每千克16000抗Xa单位的剂量下，肝素血水平非常低。低分子量肝素片段在每千克1000抗Xa单位的剂量下不会穿过胎盘。然而，对于更高的剂量（每千克8000和16000抗Xa），这种肝素片段使胎儿的肝素血水平高于市售肝素所产生的水平。
