Pasupathy D, Smith G C S
Department of Obstetrics and Gynaecology, Addenbrookes NHS Trust, Cambridge, UK.
Minerva Ginecol. 2005 Aug;57(4):397-410.
Antepartum stillbirth is the single most common cause of perinatal death. Antepartum stillbirth is associated with fetal abnormality, congenital infection, rhesus isoimmunisation, maternal medical conditions, and complications of pregnancy, such as pre-eclampsia and placental abruption. However, the majority have no direct obstetric cause and are referred to as unexplained. Many of these so-called unexplained deaths are associated with growth restriction. Maternal characteristics, such as age and smoking, are associated with an increased risk of antepartum stillbirth. The risk of stillbirth in late pregnancy is related to the function of the placenta in early pregnancy. Placental function can be assessed using circulating markers in the mothers blood, such as pregnancy associated plasma protein A and alpha-fetoprotein. Invasion of the trophoblast into the uterine vessels is associated with decreased resistance to flow in the uterus and impaired placentation is reflected in high resistance Doppler flow velocity waveforms in the utero-placental circulation. Both circulating placental markers and Doppler indices of resistance to flow are predictive of the risk of antepartum stillbirth. However, none of these tools has sufficient positive predictive value to justify population based screening. Future research in unexplained stillbirth should be directed towards developing better predictive tests to identify women at high risk and the evaluation of interventions in large scale trials.
产前死产是围产期死亡最常见的单一原因。产前死产与胎儿异常、先天性感染、恒河猴血型不合、母亲的医疗状况以及妊娠并发症（如先兆子痫和胎盘早剥）有关。然而，大多数产前死产并无直接的产科原因，被称为原因不明。这些所谓原因不明的死亡中有许多与生长受限有关。母亲的特征，如年龄和吸烟，与产前死产风险增加有关。妊娠晚期死产风险与妊娠早期胎盘功能有关。胎盘功能可通过检测母亲血液中的循环标志物来评估，如妊娠相关血浆蛋白A和甲胎蛋白。滋养层侵入子宫血管会导致子宫血流阻力降低，而胎盘形成受损则表现为子宫胎盘循环中高阻力的多普勒血流速度波形。循环胎盘标志物和血流阻力多普勒指数均可预测产前死产风险。然而，这些工具均没有足够高的阳性预测价值来证明基于人群的筛查的合理性。未来关于原因不明死产的研究应致力于开发更好的预测性检测方法，以识别高危女性，并在大规模试验中评估干预措施。
