羊水细胞染色体核型分析与高龄孕妇年龄因素的相关性

Relationship between fetal karyotype and age of pregnancy

目的通过对高龄孕妇（≥35周岁）染色体核型结果的分析，探讨提高高龄孕妇行羊水细胞遗传学诊断年龄标准的可能性。方法采用回顾性队列研究，分析了2003年7月至2015年8月在宁波市妇女儿童医院细胞遗传室进行羊水细胞染色体检查的5176例高龄孕妇病例资料，选取其中产前筛查检测的目标染色体（13号、18号、21号）以及性染色体X和Y的阳性样本，按年龄分组，利用χ2检验比较相邻的两个年龄组的阳性率的差异。结果在15408份样本中，共发现目标染色体（13号、18号、21号）和性染色体的异常262份，阳性率为1．70％；高龄孕妇共5176例，其中目标染色体（13号、18号、21号）和性染色体异常的82例，阳性率占高龄孕妇的1．58％。统计发现从35岁到〉40岁每个年龄组孕妇的阳性率分别为0．95％（11／1156）、0．94％（9／954）、0．87％（10／1144）、2．16％（14／648）、2．16％（10／464）、2．51％（10／399）和4．38％（18／411），χ2检验显示只有37岁与38岁组的阳性率差异有统计学意义（χ2=5．181，P=0．023），其他各组与前一个年龄组比较后，染色体的阳性率差异无统计学意义χ2值依次为〈0．001、0．028、〈0．001、0．117、2．129，P值依次为0．985、0．868、0．995、0．733、0．145）。结论以38周岁作为孕妇行羊水染色体分析的指征值得探讨。

Objective To evaluate the possibility of elevating the age line for pregnant women with advanced age to conducted amniocentesis. Methods A retrospective cohort study was performed. The information of 5 176 advanced age pregnant women in July 2003 to August 2015 from Ningbo Women and Children Hospital were collected and analyzed. Grouped the patients by age, using chi-square analysis, comparing the difference of abnormal rate of target chromosomes （13, 18, 21 ） and sex chromosomes （X and Y） between the adjacent two age groups. Results Total of 15 408 cases were screened. Among these, 262 cases were diagnosed with abnormal chromosome. The positive rate was 1.70%. Total of 5 176 advanced age pregnant women were included, 82 women were found with abnormal target chromosomes （ 13, 18, 21 ） and sex chromosome. The positive rate was 1.58% （82/5 176）. For age groups, the positive rates were 0. 95% （11/1 156）, 0. 94% （9/954）, 0. 87% （10/1 144）, 2.16% （ 14/648）, 2. 16% （ 10/464）, 2. 51% （ 10/ 399） and 4. 38% （18/411 ） respectively. Chi-square analysis results showed that the positive rate between group of 37 and 38 was significant difference （ chi-square value of 5. 181, P value of 0. 023 ）. There were no significant differences among all remained groups （ chi-square value： 〈0. 001, 0. 028, 〈 0. 001, 0. 117, 2. 129 respectively, P value： 0. 985, 0. 868, 0. 995, 0. 733, 0. 145 respectively ）. Conclusion It is worthwhile to elevate the age of pregnant women up to 38 years old as the age line for the indications of amniotic fluid chromosome analysis.