Objective To define an evidence-based conclusion concerning ultrasound screening for fetal genital system malformations during pregnancy. Methods In order to assess whether or not ultrasound screening for fetal genital system malformations is effective and feasible, we searched The Cochrane Library (Issue 3, 2009), MEDLINE (1981 to 2009), ACP Journal Club (1991 to 2008), and BMJ Clinical Evidence (1999 to 2008) for systematic reviews, randomized controlled trials (RCTs), cohort studies, and controlled clinical trials. Results Five cohort studies and three crosssectional studies were retrieved. The results showed ultrasound screening detected fetal sex determination by the contour of the rump and the angle of the genital tubercle to a horizontal line through the lumbosacral skin surface in the first trimester. Scrotal size and penile length increases with gestational age for male fetuses, and by 32 weeks, bilateral testicular descent was observed in most cases. Ultrasonographic scans, fetal genetic studies, and hormonal assays of amniotic fluid can diagnosis certain diseases, fetal sex differentiation disorders, fetal endocrinal disorders, and chromosome abnormality. Conclusion The findings of this study should reassure physicians and parents alike that ultrasound screening is an reliable option for the prenatal diagnosis of fetal genital system malformations, but more randomized controlled trials are needed to further supply relevant evidence.
目的 分析死胎死亡原因及可能的相关因素，为降低死胎发生的措施提供依据。 方法 对2007年1月－2011年12月住院分娩的609例死胎（≥28周） 的病例资料进行回顾性分析,包括对产检次数差异、死胎性别、死胎孕周分布、母亲年龄差别、母亲文化程度等进行统计分析。 结果 ① 死胎的原因依次为：胎儿因素（41.2%），母体因素（24.1%），胎盘因素（21.7%）及不明原因（13.0%）；其中胎儿畸形、重度子痫前期及胎盘早剥为主要原因；② 母亲的文化程度低、未建卡或未正规产检者死胎发生的几率高于正规产检者，差异有统计学意义（P＜0.05）。 结论 加强围产保健，早期筛查胎儿畸形、防治妊娠期并发症及合并症等都有助于降低死胎的发生率。
Objective To formulate an evidence-based conclusion concerning ultrasound screening for fetal malformations for a pregnant woman after 12 gestational weeks. Methods Based on the clinical problem of whether pregnant women need ultrasound screening for fetal malformations after 11-14 gestational weeks, we used “ultrasound or sonography and prenatal or fetal at first trimester or 11-14 weeks; ultrasound exposure; fetal development” as the keywords and searched The Cochrane Library (Issue 4, 2008), MEDLINE (1981 to 2008), ACP Journal Club (1991 to 2008), and BMJ Clinical Evidence (1999 to 2008) for systematic reviews, randomized controlled trials (RCTs) and controlled clinical trials. The methodological quality of the included studies was assessed to identify the current best evidence. Results Three systematic reviews, two RCTs and ten cohort studies were retrieved. The results showed ultrasound screening detected different fetal malformations in the first, second and third trimester. Not all of the fetal malformations could be detected through prenatal ultrasound screening. Nuchal translucency (NT) measurement as a tool for screening chromosomally abnormal fetuses and detecting fetal malformations by ultrasound proved to be effective if performed within 11-14 gestational weeks. The routine second trimester screening, however, could not be replaced by a detailed ultrasound examination at 11-14 gestational weeks. Most of the trials concluded that the effect of ultrasound on a fetus was not harmful. Conclusion The findings of this study should reassure physicians and parents alike that ultrasound screening is an appropriate option for the pregnant women after 12 gestational weeks.