Wang Ruixue, Yu Yang, Xi Qi, Jiang Yuting, Zhu Haibo, Li Shibo, Liu Ruizhi, Zhang Hongguo
Center for Reproductive Medicine and Center for Prenatal Diagnosis, First Hospital, Jilin University, Changchun, China.
Department of Pediatrics, Genetics Laboratory at University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
Medicine (Baltimore). 2019 Sep;98(38):e17200. doi: 10.1097/MD.0000000000017200.
The universal two-child policy has now been fully implemented in China. This change requires adaptations to maternal care and childcare systems, but the features of prenatal diagnosis before and after implementation of the policy have not been reported.We conducted a retrospective study of 6736 prenatal cytogenetic diagnoses performed on amniotic fluid cells over a 4-year period, including 2 years before and after implementation of the second child policy. Amniotic fluid cells collected through amniocentesis were cultured, harvested, and stained for chromosome analysis using standard laboratory protocols.The study included 3222 pregnant women referred before implementation of the policy, which we used as a control group, and 3514 pregnant women referred after policy implementation as an investigational study group. There were significantly fewer pregnant women aged <25 years in the investigational group than in the control group (P < .001). There were no significant between-group differences for other pregnant women aged >31 years and 27-28 years old (P > .05). A total of 358 cases with chromosomal abnormalities were diagnosed, including 129 (4%, 129/3222) in the control group which was significantly lower than the 229 (6.5%, 229/3514) in the study group (P < .001). In particular, significantly more trisomy 21 cases were observed in the study group than in the control group (120 vs 59). More pregnant women underwent non-invasive prenatal testing (NIPT) in the study group (46%) than in the control group (20%). In the study group, the average age of pregnant women who underwent NIPT was significantly higher than that of women who did not receive NIPT (P < .05). However, there were no significant between-group differences for the control group (P > .05).The number of cases with chromosomal abnormalities increased in northeastern China in the 2 years after implementation of the two-child policy. The number of pregnant women of advanced maternal age did not increase significantly, perhaps because of the widespread application of NIPT. However, the number of fetuses with Down syndrome increased significantly, suggesting that prenatal screening and diagnosis should be strengthened.
中国现已全面实施普遍二孩政策。这一变化要求对孕产妇保健和儿童保育系统进行调整，但政策实施前后产前诊断的特征尚未见报道。
我们对4年间6736例羊水细胞产前细胞遗传学诊断进行了回顾性研究，包括二孩政策实施前后各2年。通过羊膜穿刺术采集的羊水细胞按照标准实验室规程进行培养、收获及染色以进行染色体分析。
该研究纳入政策实施前转诊的3222例孕妇作为对照组，以及政策实施后转诊的3514例孕妇作为研究组。研究组中年龄＜25岁的孕妇明显少于对照组（P＜0.001）。其他年龄＞31岁及27 - 28岁的孕妇组间差异无统计学意义（P＞0.05）。共诊断出358例染色体异常病例，其中对照组129例（4%，129/3222），显著低于研究组的229例（6.5%，229/3514）（P＜0.001）。特别是，研究组中观察到的21三体病例明显多于对照组（120例对59例）。研究组中接受无创产前检测（NIPT）的孕妇比对照组（20%）更多（46%）。在研究组中，接受NIPT的孕妇平均年龄显著高于未接受NIPT的孕妇（P＜0.05）。然而，对照组组间差异无统计学意义（P＞0.05）。
二孩政策实施后2年，中国东北地区染色体异常病例数增加。高龄孕产妇数量没有显著增加，可能是因为NIPT的广泛应用。然而，唐氏综合征胎儿数量显著增加，提示应加强产前筛查和诊断。
