Russo M, Galanti B
Istituto di Clinica delle Malattie Infettive, I Facoltà di Medicina e Chirurgia dell'Università di Napoli.
Clin Ter. 1990 Sep 30;134(6):383-92.
Toxoplasma gondii can be transmitted from mother to fetus during primary maternal infection acquired after or, possibly, slightly before conception. The incidence of congenital infection is highest in the third trimester, while severity is greatest when maternal infection is acquired during the first trimester. About 50 per cent of mothers who acquire the infection during gestation, if not treated, will give birth to infected infants. Incidence of congenital toxoplasmosis varies from 0.5 to 6.5 cases per 1000 live births. Serologic screening before or very early in pregnancy is required to identify seronegative women who are at risk to acquire the infection during pregnancy. Prevention of congenital toxoplasmosis is obtained by educating pregnant women at risk about how to prevent the infection and by diagnosing acute infection of mother. Every mother who demonstrates seroconversion for toxoplasmosis during pregnancy has to be treated as soon as possible. Therapy is based on spiramycin that achieves high concentrations in the placenta; if the fetus is infected pyrimethamine plus sulphonamides are administered since fourth month. Chemotherapy of the infected pregnant mother reduces the incidence of congenital toxoplasmosis and the severity of the disease in the newborn. Intrauterine infection can be detected by fetal blood sampling, by amniocentesis and ultrasound examination; prenatal diagnosis is mandatory if an abortion is being considered.
弓形虫可在孕期初次感染时由母亲传染给胎儿，孕期初次感染发生在受孕后或可能在受孕前稍早时。先天性感染的发生率在妊娠晚期最高，而当母亲在妊娠早期感染时，疾病的严重程度最大。孕期感染弓形虫的母亲中，约50%若不治疗，将产下受感染的婴儿。先天性弓形虫病的发病率为每1000例活产中有0.5至6.5例。需要在怀孕前或怀孕早期进行血清学筛查，以识别有在孕期感染风险的血清学阴性女性。通过对有风险的孕妇进行如何预防感染的教育以及诊断母亲的急性感染来预防先天性弓形虫病。每位在孕期弓形虫血清学转换呈阳性的母亲都必须尽快接受治疗。治疗基于螺旋霉素，其在胎盘中可达到高浓度；如果胎儿受到感染，自妊娠第四个月起给予乙胺嘧啶加磺胺类药物。对受感染的孕妇进行化疗可降低先天性弓形虫病的发病率以及新生儿疾病的严重程度。可通过胎儿血样采集、羊膜穿刺术和超声检查检测宫内感染；如果考虑堕胎，则必须进行产前诊断。
