Widlund Kjerstin Ferm, Gottvall Tomas
Department of Obstetrics and Gynecology, Vrinnevi Hospital, Centre of Pediatrics and Obstetrics in Ostergötland, Norrköping, Sweden.
Acta Obstet Gynecol Scand. 2007;86(2):167-71. doi: 10.1080/00016340601048012.
Open fetal neural tube defects are often followed by an increase in alpha-Fetoprotein concentration in amniotic fluid. For over 25 years there has been a routine to measure amniotic fluid alpha-Fetoprotein in conjunction with early genetic amniocentesis. The efficacy of such a screening test in a low-risk population has been questioned but never evaluated in a Swedish population.
Data were reviewed retrospectively from all consecutive early second-trimester genetic amniocenteses from two hospitals during the years 1993-2003. Indications for the genetic amniocenteses were maternal age > or = 35 years, maternal anxiety or a history of fetal aneuploidy. A questionnaire was sent to all obstetric clinics in Sweden regarding current common policy and experience of routine amniotic fluid alpha-Fetoprotein measurements, in the detection of open fetal neural tube defects.
A total of 1,813 samples were included. In eight cases (0.4%) the amniotic fluid alpha-Fetoprotein concentrations were > or = 3 multiples of median, but five of them were false positive (63%). Out of the three true positive cases, one had clinical relevance. In the other two cases the detection of open fetal neural tube defects was of subordinate importance. In Sweden, during 2004, 91% of the obstetric clinics performed routine assessment of amniotic fluid alpha-Fetoprotein at second-trimester genetic amniocentesis, but only 9% regarded the analysis useful in clinical practice.
According to our results, routine measurement of amniotic fluid alpha-Fetoprotein in early second-trimester genetic amniocentesis, to rule out a risk of open fetal neural tube defects, does not seem justified. The clinical usefulness seems to be limited.
开放性胎儿神经管缺陷常伴有羊水甲胎蛋白浓度升高。25 多年来，一直有在早期遗传羊膜腔穿刺术时常规检测羊水甲胎蛋白的做法。这种筛查试验在低风险人群中的有效性受到质疑，但从未在瑞典人群中进行过评估。
回顾性分析了 1993 年至 2003 年期间两家医院所有连续进行的孕中期早期遗传羊膜腔穿刺术的数据。遗传羊膜腔穿刺术的指征为孕妇年龄≥35 岁、孕妇焦虑或有胎儿非整倍体病史。向瑞典所有产科诊所发送了一份问卷，询问有关常规测量羊水甲胎蛋白以检测开放性胎儿神经管缺陷的现行通用政策和经验。
共纳入 1813 份样本。8 例（0.4%）羊水甲胎蛋白浓度≥中位数的 3 倍，但其中 5 例为假阳性（63%）。在 3 例真阳性病例中，1 例具有临床相关性。在另外 2 例中，开放性胎儿神经管缺陷的检测重要性较低。2004 年在瑞典，91%的产科诊所在孕中期遗传羊膜腔穿刺术时进行羊水甲胎蛋白的常规评估，但只有 9%的诊所认为该分析在临床实践中有用。
根据我们的结果，在孕中期早期遗传羊膜腔穿刺术中常规测量羊水甲胎蛋白以排除开放性胎儿神经管缺陷的风险似乎没有道理。其临床实用性似乎有限。
