Sadovnick A D, Baird P A
Can Med Assoc J. 1983 Nov 15;129(10):1109-10.
Reports of an apparent decline in the incidence of neural tube defects (NTDs) have come from various parts of the world. If these findings are consistent they would have an important impact on prenatal diagnosis and on screening programs. The incidence of NTDs over a 10-year period was examined in British Columbia, a province that has a population-based health surveillance registry through which there is virtually complete ascertainment of liveborn infants with NTDs. The results showed a significant decrease in incidence only for stillborn infants with anencephaly. The increased use of ultrasonography and the subsequent termination of pregnancies in which the fetus has been found to have anencephaly may explain this observation.
世界各地均有神经管缺陷（NTDs）发病率明显下降的报道。如果这些研究结果具有一致性，将会对产前诊断和筛查项目产生重大影响。我们对不列颠哥伦比亚省10年间的神经管缺陷发病率进行了研究，该省拥有一个基于人群的健康监测登记系统，通过这个系统几乎能完全确定患有神经管缺陷的活产婴儿。结果显示，仅无脑儿死产儿的发病率显著下降。超声检查的更多使用以及随后对发现胎儿患有无脑儿的妊娠终止，可能解释了这一现象。
