Prenatal diagnosis using polymerase chain reaction on amniotic fluid for congenital toxoplasmosis

OBJECTIVE: To evaluate sensitivity, specificity, and predictive values of a prenatal amniotic fluid (AF) polymerase chain reaction (PCR) test for diagnosis of congenital toxoplasmosis. METHODS: A multicenter prospective study was done on 271 women with proved primary Toxoplasma infection during pregnancy and who had amniocentesis for prenatal diagnosis by PCR. Live-born infants were eligible for analysis only if a serologic follow-up could assess a definitive infection status. RESULTS: Of the 270 evaluable cases, 75 were congenitally infected, 48 of whom had a positive PCR at prenatal diagnosis. Overall sensitivity of PCR on AF was estimated at 64% (95% confidence interval [CI] 53.1%, 74.9%), negative predictive value of 87.8% (95% CI 83.5%, 92.1%), whereas specificity and positive predictive value were 100% (95% CIs 98%, 100% and 92.3%, 100%, respectively). Among cases with congenital toxoplasmosis, there were no significant differences between those with positive or negative PCR with regard to median gestational age at maternal infection, interval between maternal infection and amniocentesis, or duration of treatment before amniocentesis. However, sensitivity of PCR was found to be significantly higher for maternal infections that occurred between 17 and 21 weeks' gestation (P <.02). CONCLUSION: A negative PCR of AF cannot rule out congenital infection. In this case, continuation of treatment with spiramycin combined with ultrasonographic follow-up and postnatal follow-up are warranted. Our results also suggest presumptive treatment combining pyrimethamine and sulfonamides in case of maternal infection occurring late in pregnancy.     

Prenatal diagnosis of congenital toxoplasmosis: a multicenter evaluation of different diagnostic parameters.

OBJECTIVE: Our purpose was to evaluate different methods of diagnosing congenital toxoplasmosis prenatally by amniocentesis and cordocentesis. STUDY DESIGN: In a retrospective multicenter study, we investigated consecutive women who had seroconversion for Toxoplasma gondii during pregnancy and who underwent either amniocentesis or cordocentesis or both to obtain a prenatal diagnosis of fetal toxoplasmosis. Data were obtained from 122 patients recruited in 6 different European Toxoplasma reference centers. Infants born to these mothers were followed up until 1 year of age to confirm or exclude congenital toxoplasmosis. Sensitivity, specificity, positive predictive value, and negative predictive value were measured for the following parameters: (1) detection of the parasite in amniotic fluid by mouse inoculation, (2) detection of the parasite in amniotic fluid by in vitro cell culture, (3) detection of Toxoplasma deoxyribonucleic acid in amniotic fluid by a polymerase chain reaction assay, (4) detection of the parasite in fetal blood by mouse inoculation, (5) detection of specific immunoglobulin M antibodies in fetal blood, and (6) detection of specific immunoglobulin A antibodies in fetal blood. RESULTS: The polymerase chain reaction test performed on amniotic fluid had the highest level of sensitivity (81%) and also a high level of specificity (96%). The combination of the polymerase chain reaction test and mouse inoculation of amniotic fluid increased sensitivity to 91%. The sensitivity of immunoglobulins M and A in fetal blood was 47% and 38%, respectively. In congenitally infected fetuses a negative correlation was observed between positive serologic parameters and gestational age at the time of maternal infection and at prenatal diagnosis. CONCLUSION: Congenital toxoplasmosis is best predicted by prenatal examination with the combination of T gondii polymerase chain reaction and mouse inoculation of amniotic fluid. The role of cordocentesis in the diagnosis of congenital toxoplasmosis is limited.     

Prenatal diagnosis of congenital toxoplasmosis by duplex real-time PCR using fluorescence resonance energy transfer hybridization probes

The diagnosis of congenital toxoplasmosis frequently relies on PCR tests of amniotic fluid (AF). A duplex real-time quantitative PCR test based on fluorescence resonance energy transfer was developed to quantify the parasite load and to decrease the risk of contamination. An internal control based on the detection of 10 pg mouse DNA added to the AF was included to check for PCR efficiency. The relationship between the parasite load and the occurrence of ultrasonographic abnormalities in 87 samples of AF was analyzed. Seven AF (8%) had a parasitic load > 10(3); 14 (16%) had > 10(2)-< or =10(3); 26 (30%) had > 10-< or = 10(2); and 40 (46%) had < or = 10 parasites/ml. Four of the six AF with cerebral ventriculomegaly had >10(3) parasites/ml. The other two had 130 and 24 parasites/ml, respectively. No parasitic loads of > 10(3) parasites/ml and no ultrasonographic abnormalities were observed in the 11 AF with maternal toxoplasmosis in the third trimester. Therefore, there is a trend to associate high parasite count with ultrasonographic abnormality, but the main concern remains early maternal infection. The importance of quantification should be better evaluated with postnatal studies. The duplex LightCycler PCR test currently provides rapid and safe results.     

Prenatal diagnosis of congenital cytomegalovirus infection

OBJECTIVE: To assess prospectively the diagnostic reliability and prognostic significance of prenatal diagnosis of cytomegalovirus (CMV) infection. METHODS: One hundred ten pregnant women (four with twin pregnancies) with a risk of congenital CMV infection were investigated. Prenatal diagnosis was carried out by amniocentesis and fetal blood sampling (n = 75) or amniocentesis alone (n = 35). Serial ultrasonographic examinations were performed from time of referral until pregnancy end. All infected neonates were given long-term follow-up. Autopsy was performed in all cases of termination of pregnancy. RESULTS: Nearly 23% (26 of 114) of fetuses were infected and prenatal diagnosis was positive in 20 cases. Sensitivity of prenatal diagnosis was 77% and specificity 100%. In eight cases, parents requested termination of pregnancy on the basis of abnormal ultrasonographic findings and/or biologic abnormalities in fetal blood. In 12 cases, parents decided to proceed with the pregnancy. In this group, one intrauterine and one neonatal death were observed. In one case, prenatal diagnosis revealed an abnormal cerebral sonography and the infant had bilateral hearing loss at birth. In 15 cases (nine positive and six false-negative prenatal diagnoses), no apparent lesion was present at birth, nor did it develop during the follow-up period (mean 31 months). In 88 (77.2%) of 114 infants, no evidence of vertical transmission was found during the pre- or postnatal period. CONCLUSION: Prenatal diagnosis provides the optimal means for both diagnosing fetal infection (amniocentesis) and identifying fetuses at risk of severe sequelae (ultrasound examination, fetal blood sampling), thus allowing proper counseling.     

Prenatal diagnosis of symptomatic congenital cytomegalovirus infection

OBJECTIVE: The aim of this study was to evaluate whether the amniotic viral load of mothers with primary cytomegalovirus infection correlate with fetal or neonatal outcomes. STUDY DESIGN: Sixty-eight of 138 pregnant women with primary infection defined by immunoglobulin G seroconversion or the presence of immunoglobulin M with low immunoglobulin G avidity accepted amniocentesis. Polymerase chain reaction and quantitative polymerase chain reaction were used to detect amniotic fluid cytomegalovirus. Cytomegalovirus infection in neonates was determined by means of urinary viral isolation during the first week after birth or the histologic examination of tissue from aborted fetuses. RESULTS: Cytomegalovirus infection was found in 16 fetuses and neonates (23%), 5 of whom had symptoms. Quantitative polymerase chain reaction showed that the presence of >/=10(3) genome equivalents predicted mother-child infection with 100% probability; >/=10(5) genome equivalents predicted the development of a symptomatic infection. CONCLUSION: Fewer than expected cytomegalovirus-infected fetuses are at risk for development of cytomegaloviral disease, and this fact may be useful in counseling pregnant women with primary cytomegalovirus infection.     

Prenatal diagnosis of Fukuyama congenital muscular dystrophy

Fukuyama congenital muscular dystrophy (FCMD) is characterized by infantile hypotonia, symmetrical generalized muscle weakness, and neuronal migration disturbances that result in changes consistent with cobblestone lissencephaly with cerebral and cerebellar cortical dysplasia. FCMD is recognized as an autosomal recessive genetic defect. Genetic counselling is recommended for parents at risk of having a child with FCMD. Given the high risk and overwhelming prospect of having another child with this incurable devastating condition leads many couples to consider prenatal diagnosis. In Japanese families, haplotype analysis using microsatellite markers is available. In non-Japanese families, DNA sequence analysis is available. Both disease-causing alleles of an affected family member must be identified before prenatal testing can be performed.     

Prenatal diagnosis of Milroy's primary congenital lymphedema

Milroy's primary congenital lymphedema (PCL) (hereditary lymphedema type I, Milroy disease) is present at birth, and mostly affects the dorsal aspects of feet. It is mostly a life-long condition but does not affect longevity. Complications are rare except for chronic discomfort and warmness of affected areas. PCL is an autosomal dominant disease with incomplete penetrance due to a mutation in the gene locus encoding for VEGFR3 with resultant dysgenesis of microlymphatic vessels. We report on two fetuses where ultrasonographic examination at 15 weeks of gestation showed significant edema of the dorsal aspects of both feet with no evidence of other major malformations. Whereas in one fetus the edema resolved completely, it persisted in the second fetus and proved after birth to be of lymphedematous nature. To the best of our knowledge, this is the first report of early prenatal diagnosis of primary congenital lymphedema via fetal ultrasonographic examination and of spontaneous resolution of lymphedema during fetal life.     

Prenatal sonographic diagnosis of congenital hiatal hernia

OBJECTIVES: To report a rare case of congenital hiatal hernia illustrating the importance of its prenatal diagnosis as well as to discuss the prenatal sonographic criteria. CASE REPORT: A case of congenital hiatal hernia was diagnosed by ultrasound at 33 weeks of gestation. After a normal second-trimester morphologic ultrasound examination, a hypoechogenic mass was detected in the posterior mediastinum juxtaposed to the vertebral body and seemed to be in continuity with the intra-abdominal stomach bubble. Congenital hiatal hernia was suspected mainly because of the dynamic position of the stomach during the examination, without mediastinal shift, and normal appearance of the diaphragm on parasagittal sections of the thorax. Postnatal management was planned with no urgency and surgery was successfully performed, confirming the diagnosis. CONCLUSION: This rare case illustrates the importance of prenatal diagnosis of congenital hiatal hernia for prenatal counseling and postnatal management. The ultrasound criterion for prenatal diagnosis is the presence of a herniated stomach in the posterior mediastinum, sometimes having a dynamic position during examination, with no mediastinal shift associated with normal diaphragm appearance on parasagittal sections of the thorax.     

先天性心脏畸形的产前诊断及临床分析

目的探讨先天性心脏畸形的产前诊断及临床意义。方法本研究应用Yagel5个心脏横面和心脏长轴切面进行胎儿心脏扫描，并有效多普勒血流技术、彩色血流、M型超声等超声仪器各项功能技术，对2002至2004年982例先天心脏畸形高危患者进行胎儿心脏全方位检查，并对引产胎儿进行尸体解剖核对产前诊断的正确性，并进行胎儿染色体分析；对产前诊断未发现明显异常的胎儿进行临床随访，胎儿出生后进行新生儿或要儿心脏超声检查，判定产前诊断的正确性。结果（1）982例先天心脏畸形高危患者中，检查发现胎儿心脏结构异常为46例（4．7％）。其中应用单纯四腔心即能诊断的先天性胎儿心脏结构异常为32例，其余14例需同时结合其他心脏检测平面诊断。（2）41例引产胎儿中，32例进行尸体解剖，病理结果与产前超声检查符合率为93．8％（30／32），其中1例患者病理诊断为永存动脉干畸形，产前诊断为法洛四联症；另1例为右心室双流出道畸形，产前诊断为大动脉转位。（3）46例患者中，32例进行胎儿染色体检测，合并染色体异常8例（25．0％）。（4）5例为产前诊断右心系统略大胎儿，分娩后新生儿或要儿心脏超声检查，结果与产前基本相同，表现为单纯右心系统略大，但新生儿和要儿无任何临床症状。（5）936例产前诊断为正常胎儿心脏患者，新生儿或要儿心脏超声检查发现室间隔缺损1例，动脉导管未闭2例，房间隔缺损1例。结论（1）应用本研究方法，以先天心脏畸形高危患者为筛查对象，产前诊断先天性心脏畸形阳性率为4．7％，产前诊断与尸体解剖符合率为93．8％。（2）应用本研究方法可使高危人群产前诊断胎儿先天性心脏畸形的敏感性达92．0％，特异性达99．6％。（3）单纯左右心比例轻中度失调胎儿可能有较好的临床预后。     

Prenatal diagnosis of congenital lobar fluid overload

Prenatal congenital lobar fluid overload (CLFO), which was first described by Ramsay and Byron, is identical to postnatal congenital lobar overinflation. It is characterized by progressive lobar overexpansion that compresses the other adjacent lung lobes. The underlying cause can be an intrinsic cartilaginous abnormality or an extrinsic airway compression. It may be associated with cardiovascular anomalies in 12%–14% of cases and affects males more frequently than females. Most cases are diagnosed postnatally, but early antenatal diagnosis and sequential follow-up are attempted for early treatment, if clinically indicated. This article provided a thorough review of CLFO, including prenatal diagnosis and differential diagnoses, as well as comprehensive illustrations of the perinatal imaging findings of CLFO. Prenatal diagnosis of fetal lung lesions should include CLFO in the differential diagnosis and prompt investigation for associated anomalies.     

Prenatal diagnosis of congenital malformations in 500 pregnancies

The organization, techniques used and diagnostic findings of 500 prenatal diagnoses are reported in detail. In 15 cases the pregnancy was terminated because of abnormal laboratory findings. Follow-up of the remaining pregnancies revealed a perinatal mortality of 1.7%, and the risk of an abortion induced by amniocentesis, performed in the 15–16th wk, to be 1–2%. Serious counseling problems arose in 2 cases with trisomy X, in 2 instances of a balanced chromosome translocation and in 1 case of a de novo translocation.     

Prenatal diagnosis of familial congenital pyloric atresia.

Familial congenital pyloric atresia is a rare malformation of the fetal gastrointestinal tract. It usually manifests as maternal polyhydramnios and enlarged fetal stomach on ultrasound scan. Sonographic prenatal diagnosis and management of a pregnancy complicated by familial congenital pyloric atresia are presented.     

Prenatal diagnosis and management of congenital heart disease

Thirty-two fetuses were diagnosed as having congenital heart disease (CHD). The major indications for level II echocardiography other than suspected cardiac abnormalities were fetal malformations, nonimmune hydrops and cardiac arrhythmia. Only three patients had a previous history of fetal CHD. No false-abnormal diagnosis of severe CHD was made. Aortic arch anomalies represented the major diagnostic problem among the six correct but incomplete diagnoses. Sixty-one percent of the fetuses were growth retarded, thus confirming the severity of their CHD. Chromosomal anomalies and extracardiac malformations were associated in 19% and 44% of the fetuses, respectively. Obstetric management and fetal prognosis in cases of extracardiac malformations were greatly influenced by the diagnosis of CHD. The poorest perinatal outcome was associated with heart failure. The only intrauterine deaths occurred in that group, and only one neonate survived. The outcome was more favorable in neonates without other malformations or heart failure. Four of ten (40%) of those neonates survived, while the overall perinatal survival rate was 24%.