ACOG Guidelines at a Glance: Key points about 4 perinatal infections


ACOG指南概览：四种围产期感染的关键点


This 2015 Practice Bulletin replaces one published in 2000. I will not review the basic facts about the 4 possible perinatal infections (type of virus or parasite, symptomatology, potential impact on the fetus, and methods of diagnosis in the mother and fetus); that information is in the full Practice Bulletin, which I recommend that you read. Listed here are what I consider the key diagnostic points about maternal and fetal infection, highlights of the few new findings, and information on the level A recommendations for each disease.

2015年的临床实践公告，是基于2000版的改进。所以我不会在这里给大家背书围产期4种感染的基础知识（病原体类型、症状、对胎儿的潜在影响和母胎诊断方法等）。这些基础知识在临床实践公告的全文中有谈及，大家可以自己去翻阅。这里我要列出的，是四种母胎感染的关键诊断要点、新发现的亮点，以及A级建议。


Cytomegalovirus

巨细胞病毒（CMV）


Diagnostic points

诊断要点


Risk of transmission to the fetus with maternal primary infection is approximately 30% to 40% and 0.15% to 2% with recurrent infection. If you are suspicious, check maternal immunoglobulin M (IgM) and immunoglobulin G (IgG) with avidity testing.

初始感染，由母体传播给胎儿的风险为30%~ 40%，复发感染风险为0.15%~ 2%。如果你怀疑就诊者受到感染，建议行母体免疫球蛋白M（IgM抗体）和免疫球蛋白G（IgG）亲合力检查。


New points

新的亮点


1. IgG avidity assay measures the maturity of the IgG antibody, which helps to identify a primary infection with greater accuracy than simple IgG and IgM titers. After an initial cytomegalovirus (CMV) infection, the IgG antibody produced has low avidity because it is not mature. After about 4 months, the antibodies mature, hence the high avidity. Therefore, if a woman has low-avidity IgG and positive IgM, she is likely to have a recent primary infection with CMV.

母体IgG亲合力检查识别初始感染的精度高于单纯检测IgG和IgM滴度。初始巨细胞病毒（CMV）感染后，母体内所产生的IgG抗体因为并不成熟，所以亲合力低。感染4个月后，抗体渐趋成熟，体现高亲和力。因此，如果母体低亲和力IgG和IgM阳性，则很可能在近期原发感染了CMV。


2. Use of polymerase chain reaction (PCR) on amniotic fluid is now recommended for diagnosis of fetal CMV infection. Fetal blood sampling is no onger recommended to make this diagnosis. PCR on amniotic fluid for CMV is more sensitive after 21 weeks’ gestation.

目前推荐使用羊水聚合酶链反应（PCR），诊断胎儿巨细胞病毒感染。不再推荐胎儿血取样做这个诊断。羊水巨细胞病毒 PCR的最佳检测时间为孕21周。


3. Remember that 75% of congenital CMV infections may be due to reactivation of old infection, or reinfection with a new strain of CMV, so evidence of old infection does not rule out the possibility of fetal CMV.

切记，75％的先天性巨细胞病毒感染可能源于既往的感染，或巨细胞病毒的新菌株再感染后活化。所以，既往有感染者，不排除胎儿CMV的可能性。