通过对北京市5年先天性脑积水(CH)监测资料分析，了解北京市胎儿及婴儿的CH发生率、诊断及转归。

选择2015年1月至2019年12月，北京市出生缺陷监测系统内监测对象(胎龄为13周至生后1岁)中，407例CH患儿(胎儿或婴儿)为研究对象。对其出生缺陷诊断资料进行分析。采用χ²检验，对孤立性与非孤立性CH活产儿婴儿期存活率进行统计学比较。本研究遵循的程序符合2013年新修订的《世界医学协会赫尔辛基宣言》要求。

本研究时间(5年)内，北京市胎儿及1岁内婴儿的CH发生率为3.60×10^-4(407/1 129 861)。这407例CH患儿中，82例(20.15%)合并颅外畸形，20例(4.91%)合并染色体异常；CH胎儿的产前诊断率为92.38%(376/407)，超声检出CH胎儿时，其胎龄为24周(23~35周)，其中胎龄≥28周者占26.06%(98/376)。376例产前被诊断的CH胎儿中，44例采取产前胎儿超声联合MRI检查，而且通过胎儿MRI检查对4例胎儿的颅内畸形具体类型进行了补充诊断。本研究未发现CH患儿的孕母合并宫内感染；103例CH活产儿中，73例孤立性CH患儿的婴儿期(1岁内)存活率为72.6%(53/73)，高于30例非孤立性CH患儿的婴儿期存活率(60.0%，18/30)，二者比较，差异无统计学意义(P>0.05)。

北京市在预防出生缺陷发生的三级防控体系中，对CH胎儿与婴儿的一级、二级防控已取得效果。对孕妇全孕期多次动态胎儿超声检查，必要时联合胎儿MRI检查，对非孤立性CH胎儿同时采取细胞遗传学和分子遗传学检测，可进一步提高CH患儿的防控效果。

To explore the incidence, diagnosis and sequelae of congenital hydrocephalus (CH) fetus and infants of Beijing by analyzing monitoring data of CH in Beijing in nearly 5 years.

From January 2015 to December 2019, a total of 407 CH fetuses or infants in the Birth Defects Monitoring Network in Beijing from 13 weeks of gestation to 1 year after birth were selected as research subjects. Their birth defects diagnosis data were analyzed. Chi-square test was used to statistically compare the survival rate between isolated and non-isolated CH of live born infants within 0-1 year after birth. The procedures followed in this study were in line with World Medical Association Declaration of Helsinki revised in 2013.

The incidence of CH in fetuses and infants within 1 year after birth in nearly 5 years in Beijing was 3.60×10^-4 (407/1 129 861). Among 407 cases of CH fetuses or infants, 82 cases (20.15%) were complicated with extracranial malformation, and 20 cases (4.91%) were complicated with chromosome abnormalities. The prenatal diagnosis rate of CH fetus was 92.38%(376/407). When fetus diagnosed with CH by fetal ultrasound, their gestational age was 24 gestational weeks (23-35 gestational weeks), and fetus of gestational age ≥28 weeks were accounted for 26.06% (98/376) of the prenatal diagnosed cases. Among 376 CH fetuses diagnosed prenatally, 44 cases were examined by prenatal fetal ultrasound and magnetic resonance imaging (MRI), and 4 cases were diagnosed supplementary specific types of intracranial malformations by fetal MRI. No intrauterine infection of pregnant women was found in this study. Among 103 CH cases of live births, the survival rate within 1 year after birth of 73 infants with isolated CH was 72.6% (53/73), the survival rate of 30 infants with non-isolated CH was 60.0% (18/30), but the difference was not statistically significant (P>0.005).

In three-level prevention and control system to prevent birth defects, the primary and secondary prevention for CH fetuses or infants in Beijing has achieved results. Multiple dynamic fetal ultrasound examinations for pregnant women during pregnancy, combined with fetal MRI if necessary, and cytogenetic and molecular genetic examinations for non-isolated CH fetus may improve the prevention effects of CH.