Jauniaux E, Gulbis B
Academic Department of Obstetrics and Gynaecology, Royal Free and University College, London Medical School, 86-96 Chenies Mews, WC1E 6HX, London, UK.
Eur J Obstet Gynecol Reprod Biol. 2000 Sep;92(1):45-9. doi: 10.1016/s0301-2115(00)00424-3.
The use of coelocentesis to study placental drug transfer in the first trimester has required the adaptation of existing pharmacologic models to the changing anatomical structures present before and after 12 weeks of gestation. The biochemical properties of the coelomic and amniotic fluids are important parameters in evaluating the pharmacokinetics of drugs and toxins in early pregnancy. In particular, the protein concentration and pH of these fluids are significantly different and vary widely with gestational age. These biochemical variations are less likely to influence the distribution of inert substances such as inulin inside the first trimester conception cavities than the distribution of drugs such as diazepam or propofol. This can explain why they are not all accumulating inside the exocoelomic cavity. It has been demonstrated that the permeability of the placenta is greater in early pregnancy than at term. Furthermore, because of the slow turn-over of the coelomic fluid, substances such as nicotine to which the mother is chronically exposed accumulate inside the exocoelomic cavity. This prolonged fetal exposure to tobacco carcinogens has important teratogenic implications and should be further explored.
在孕早期使用体腔穿刺术研究胎盘药物转运，需要对现有的药理学模型进行调整，以适应妊娠12周前后不断变化的解剖结构。体腔液和羊水的生化特性是评估孕早期药物和毒素药代动力学的重要参数。特别是，这些液体的蛋白质浓度和pH值存在显著差异，并且会随着孕周的增加而有很大变化。与地西泮或丙泊酚等药物的分布相比，这些生化变化对孕早期孕腔内惰性物质（如菊粉）分布的影响较小。这可以解释为什么它们并非都在体腔外腔内蓄积。研究表明，胎盘在孕早期的通透性比足月时更高。此外，由于体腔液周转缓慢，母亲长期接触的尼古丁等物质会在体腔外腔内蓄积。胎儿长期暴露于烟草致癌物具有重要的致畸意义，值得进一步研究。
