Schneider H, Herrmann U
Universitäts-Frauenklinik Bern.
Geburtshilfe Frauenheilkd. 1990 Jan;50(1):8-14. doi: 10.1055/s-2007-1026424.
The postdate pregnancy remains an unresolved clinical problem with the threat of medicolegal consequences in cases of unfavorable outcome. Placental dysfunction leading to fetal hypoxia may develop in these pregnancies at any time and for the truly postmature fetus there is a considerable risk of asphyxia. Fetal hypoxia, accompanied with hemoconcentration due to a maternofetal fluid imbalance, leads to diminished fetal urine production and a reduced amniotic fluid volume, which can cause cord compression. According to this simplified pathophysiological cascade, the monitoring of postdate pregnancies should be based mainly on ultrasound assessment of amniotic fluid volume and cardiotocography. At our institution, instead of an obligatory induction of labor at a fixed gestational age, induction is performed when the largest amniotic fluid pocket measures less than 3 cm (vertical) or when variable decelerations of the fetal heart rate appear. A nonreactive nonstress test calls for a complete biophysical profile. As long as these monitoring techniques indicate fetal well-being, pregnancy is allowed to continue, especially in the presence of an incompatible condition of the cervix.
过期妊娠仍然是一个尚未解决的临床问题,在结局不佳的情况下存在法律后果的风险。在这些妊娠中,随时可能发生导致胎儿缺氧的胎盘功能障碍,对于真正过期成熟的胎儿,存在相当大的窒息风险。胎儿缺氧伴有母胎液体失衡导致的血液浓缩,会导致胎儿尿液生成减少和羊水量减少,进而可能导致脐带受压。根据这个简化的病理生理级联反应,过期妊娠的监测应主要基于超声评估羊水量和胎心监护。在我们机构,不是在固定孕周强制引产,而是当最大羊水暗区小于3厘米(垂直)或出现胎儿心率变异减速时进行引产。无反应型无应激试验需要进行完整的生物物理评分。只要这些监测技术表明胎儿状况良好,妊娠就可以继续,尤其是在宫颈条件不相容的情况下。