Genetic autopsy and genetic counseling for a case of fatal oligohydramnios due to de novo 17q12 deletion syndrome.

We report here a fatal oligohydramnios case, which was suspected due to autosomal recessive polycystic kidney disease at first, but genetic analysis using chorionic tissue and umbilical cord after stillbirth led to the diagnosis of 17q12 deletion syndrome. Subsequent genetic analysis of the parents showed no 17q12 deletion. In this case, if the fetus had autosomal recessive polycystic kidney disease, the recurrence rate in the next pregnancy was suspected to be 25%, but since it was a de novo autosomal dominant disorder, the recurrence rate is extremely low. When a fetal dysmorphic abnormality is detected, a genetic autopsy not only helps to understand the cause but also provides information about the recurrence rate. This information is important for the next pregnancy. A genetic autopsy is useful in cases of fetal deaths or abortions resulting from fetal dysmorphic abnormalities.

Prevalence of common aneuploidy in twin pregnancies.

The incidence of chromosomal abnormalities in twin pregnancies is not well-studied. In this retrospective study, we investigated the frequency of chromosomal abnormalities in twin pregnancies and compared the incidence of chromosomal abnormalities in dichorionic diamniotic (DD) and monochorionic diamniotic (MD) twins. We used data from 57 clinical facilities across Japan. Twin pregnancies of more than 12 weeks of gestation managed between January 2016 and December 2018 were included in the study. A total of 2899 and 1908 cases of DD and MD twins, respectively, were reported, and the incidence of chromosomal abnormalities in one or both fetuses was 0.9% (25/2899) and 0.2% (4/1908) in each group (p = 0.004). In this study, the most common chromosomal abnormality was trisomy 21 (51.7% [15/29]), followed by trisomy 18 (13.8% [4/29]) and trisomy 13 (6.9% [2/29]). The incidence of trisomy 21 in MD twins was lower than that in DD twins (0.05% vs. 0.5%, p = 0.007). Trisomy 21 was less common in MD twins, even when compared with the expected incidence in singletons (0.05% vs. 0.3%, RR 0.15 [95% CI 0.04-0.68]). The risk of chromosomal abnormality decreases in twin pregnancies, especially in MD twins.

Evaluation of the clinical performance of noninvasive prenatal testing at a Japanese laboratory.

AIM: We aimed to evaluate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of noninvasive prenatal testing (NIPT) in high-risk pregnant women. METHODS: Pregnant women who underwent GeneTech NIPT, the most commonly used NIPT in Japan, between January 2015 and March 2019, at Japan NIPT Consortium medical sites were recruited for this study. The exclusion criteria were as follows: pregnant women with missing survey items, multiple pregnancy/vanishing twins, chromosomal abnormalities in the fetus other than the NIPT target disease, and nonreportable NIPT results. Sensitivity and specificity were calculated from the obtained data, and maternal age-specific PPV and NPV were estimated. RESULTS: Of the 45 504 cases, 44 263 cases fulfilling the study criteria were included. The mean maternal age and gestational weeks at the time of procedure were 38.5 years and 13.1 weeks, respectively. Sensitivities were 99.78% (95% confidence interval [95% CI]: 98.78-99.96), 99.12% (95% CI: 96.83-99.76), and 100% (95% CI: 88.30-100) for trisomies 21, 18, and 13, respectively. Specificities were more than 99.9% for trisomies 21, 18, and 13, respectively. Maternal age-specific PPVs were more than 93%, 77%, and 43% at the age of 35 years for trisomies 21, 18, and 13, respectively. CONCLUSION: The GeneTech NIPT data showed high sensitivity and specificity in the detection of fetal trisomies 21, 18, and 13 in high-risk pregnant women, and maternal age-specific PPVs were obtained. These results could provide more accurate and improved information regarding NIPT for genetic counseling in Japan.

The Current Challenges in Developing Biological and Clinical Predictors of Congenital Cytomegalovirus Infection.

Congenital cytomegalovirus (CMV) infection may cause severe long-term sequelae. Recent studies have demonstrated that early antiviral therapy for infants with symptomatic congenital CMV (cCMV) infection may improve neurological outcomes; thus, accurate identification of newborns at high risk of cCMV infection may contribute to improved outcomes in affected children. However, maternal serological screening for cCMV infection by diagnosing primary infection during pregnancy, which is a popular screening strategy, is inefficient, because the number of cCMV infections with nonprimary causes, including reactivation of or reinfection with CMV, is larger than that of cCMV infections with primary causes. Low levels of neutralizing antibodies against pentameric complex and potent CMV-specific T cell-mediated immune responses are associated with an increased risk of cCMV infection. Conversely, our prospective cohort studies revealed that the presence of maternal fever/flu-like symptoms, threatened miscarriage/premature delivery, or actual premature delivery are risk factors for cCMV infection among both women with normal pregnancies and those with high-risk ones, regardless of whether the infection is primary or nonprimary. This review focused on host immune responses to human CMV and current knowledge of potential biological and clinical factors that are predictive of cCMV infection.

Qualitative investigation of the factors that generate ambivalent feelings in women who give birth after receiving negative results from non-invasive prenatal testing.

BACKGROUND: Women who receive negative results from non-invasive prenatal genetic testing (NIPT) may find that they later have mixed or ambivalent feelings, for example, feelings of accepting NIPT and regretting undergoing the test. This study aimed to investigate the factors generating ambivalent feelings among women who gave birth after having received negative results from NIPT. METHODS: A questionnaire was sent to women who received a negative NIPT result, and a contents analysis was conducted focusing on ambivalent expressions for those 1562 women who responded the questionnaire. The qualitative data gathered from the questionnaire were analyzed using the N-Vivo software package. RESULTS: Environmental factors, genetic counseling-related factors, and increased anticipatory anxiety, affected the feeling of ambivalence among pregnant women. Furthermore, pregnant women desired more information regarding the detailed prognosis for individuals with Down syndrome and living with them and/or termination, assuming the possibility that they were positive. CONCLUSIONS: Three major interrelated factors affected the feeling of ambivalence in women. Highlighting and discussing such factors during genetic counseling may resolve some of these ambivalences, thereby enhancing the quality of decisions made by pregnant women.

A cohort study of the universal neonatal urine screening for congenital cytomegalovirus infection.

OBJECTIVES: This prospective cohort study aimed to evaluate the efficacy of the universal neonatal urine screening, followed by diagnosis, workup and antiviral therapy for symptomatic congenital cytomegalovirus (CMV) infection to reduce neurological impairments and sequelae. METHODS: Neonates born in three facilities underwent the universal urine screening of PCR analyses for CMV-DNA. Neonates with symptomatic congenital CMV infection (cCMV) received oral valganciclovir (VGCV) of 32 mg/kg/day for six weeks or six months, and were evaluated for neurological outcomes including developmental quotient (DQ) and hearing function at around 18 months of corrected age. RESULTS: cCMV was diagnosed in 56 (0.48%) of 11,736 neonates, consisting of 23 neonates with symptomatic and 33 with asymptomatic cCMV. The incidence of cCMV in the general perinatal medical center (0.69%) was higher than that in the primary maternity hospital (0.23%, p<0.01%). Twenty of the 23 infants with symptomatic cCMV received VGCV therapy, and 19 underwent neurological assessment. Eight neonates (42%) had severe sequelae of DQ < 70, bilateral hearing dysfunction, and/or epilepsy. Four neonates (21%) had mild sequelae of DQ 70-79 or unilateral hearing dysfunction only, and seven (37%) showed normal development without any impairment. CONCLUSIONS: This study on a large scale demonstrated that a series of universal neonatal urine screening, diagnosis, workup, and VGCV therapy for neonates with symptomatic cCMV may decrease neurological impairments, because 58% of the treated infants had normal development or mild sequelae. The universal urine screening likely identifies subclinical symptomatic cCMV. Mothers with fetuses of cCMV seem to be selectively transferred to perinatal medical centers before deliveries.

Classification of factors involved in nonreportable results of noninvasive prenatal testing (NIPT) and prediction of success rate of second NIPT.

OBJECTIVE: To evaluate the reasons for nonreportable cell-free DNA (cfDNA) results in noninvasive prenatal testing (NIPT), we retrospectively studied maternal characteristics and other details associated with the results. METHODS: A multicenter retrospective cohort study in pregnant women undergoing NIPT by massively parallel sequencing (MPS) with failed cfDNA tests was performed between April 2013 and March 2017. The women's data and MPS results were analyzed in terms of maternal characteristics, test performance, fetal fraction (FF), z scores, anticoagulation therapy, and other details of the nonreportable cases. RESULTS: Overall, 110 (0.32%) of 34 626 pregnant women had nonreportable cfDNA test results after an initial blood sampling; 22 (20.0%) cases had a low FF (<4%), and 18 (16.4%) cases including those with a maternal malignancy, were found to have altered genomic profile. Approximately half of the cases with nonreportable results had borderline z score. Among the women with nonreportable results because of altered genomic profile, the success rate of retesting using a second blood sampling was relatively low (25.0%-33.3%). Thirteen (11.8%) of the women with nonreportable results had required hypodermic heparin injection. CONCLUSIONS: The classification of nonreportable results using cfDNA analysis is important to provide women with precise information and to reduce anxiety during pregnancy.

A cohort study of maternal screening for congenital Toxoplasma gondii infection: 12 years' experience.

Primary infection with Toxoplasma gondii (T. gondii) during pregnancy may cause congenital infection of the infant. This study evaluated whether screening using IgG avidity and multiplex-nested polymerase chain reaction (PCR) methods was effective for detecting a high-risk pregnancy for congenital T. gondii infection. In a prospective cohort study serum T. gondii IgG avidity was measured in 469 pregnant women who had a positive test for T. gondii antibody plus a positive or equivocal test for IgM. Multiplex-nested PCR for T. gondii DNA on amniotic fluid, maternal blood, and neonatal blood was performed with informed consent. Low (<30%), borderline (30-35%), and high (>35%) IgG avidity indices were found in 104 (22.2%), 30 (6.4%), and 305 (71.4%), respectively. A total of 12 cases had a positive PCR test for amniotic fluids of the prenatal amniocentesis or at birth, or neonatal blood. Seven of the 12 cases were diagnosed as having congenital T. gondii infection, and they had low IgG avidity indices. Congenital T. gondii infection screening using of IgG avidity and multiplex-nested PCR methods for pregnant women with a positive test for T. gondii antibody plus a positive or equivocal test for T. gondii IgM was useful for detecting a high-risk pregnancy and diagnosing congenital T. gondii infection.

Clinical factor associated with congenital cytomegalovirus infection in pregnant women with non-primary infection.

The aim of this nested case-control study was to evaluate clinical factors associated with the occurrence of congenital cytomegalovirus (CMV) infection in pregnant women with non-primary CMV infection. In a cohort study of CMV screening for 2193 pregnant women and their newborns, seven newborns with congenital CMV infection were identified among 1287 pregnant women with non-primary CMV infection that was defined as negative IgM and positive IgG with IgG avidity index >45%. In the 1287 women with non-primary CMV infection, clinical findings and complications were compared between pregnancies with and without congenital CMV infection. Clinical factors associated with the occurrence of congenital CMV infection were evaluated. The birth weight of newborns with congenital CMV infection was less than that of newborns without congenital infection (p < 0.05). Univariate logistic regression analyses demonstrated that threatened premature delivery (OR 10.6, 95%CI 2.0-55.0; p < 0.01) and multiple pregnancy (OR 7.1, 95%CI 1.4-37.4; p < 0.05) were associated with congenital infection. Multivariable logistic regression analyses demonstrated that threatened premature delivery (OR 8.4, 95%CI 1.5-48.1; p < 0.05) was a single risk factor for congenital CMV infection in pregnant women with non-primary CMV infection. This study revealed for the first time that threatened premature delivery was associated with the occurrence of congenital CMV infection in pregnant women with non-primary CMV infection, the pathophysiology of which may be closely associated with CMV reactivation during pregnancy.

Universal Screening With Use of Immunoglobulin G Avidity for Congenital Cytomegalovirus Infection.

BACKGROUND: The aim of this prospective cohort study was to evaluate the efficacy of maternal screening for congenital cytomegalovirus infection (CCI) using cytomegalovirus (CMV) immunoglobulin G (IgG) and the IgG avidity index (AI). METHODS: Pregnant women underwent screening of CMV IgG and AI measurements. IgG-negative women underwent remeasurement of IgG after educational intervention. Women with an AI ≤45% received further examinations, including measurement of CMV IgM. All newborns received polymerase chain reaction analyses of the urine, and CCI was diagnosed by the detection of CMV-DNA in the urine. Primary infection was defined as an AI <35% and/or positive IgM (>1.20 index). Serum samples from women with an AI >45% were stored, and the IgM levels were measured after delivery. The efficacy of AI and IgM for CCI screening was compared. RESULTS: A total of 1562 (71.2%) women tested positive for IgG. In this study, 10 newborns with CCI were detected. The presence of infection in 3 newborns from mothers with primary infection was predicted by screening of IgG and AI <35%. However, infection in 7 newborns from women with nonprimary infection could not be predicted by screening of CMV IgG, AI <35%, or IgM. The application of an AI <35% for CCI screening yielded 22.2% sensitivity, 95.0% specificity, 2.5% positive predictive value, and 99.5% negative predictive value and was similar to that of IgM (11.1% sensitivity, 93.2% specificity, 0.9% positive predictive value, and 92.7% negative predictive value). CONCLUSIONS: Maternal screening using CMV IgG and AI can identify pregnancies with CCI from primary infection, but overlooks a number of those from nonprimary infection.

Prediction of Congenital Cytomegalovirus Infection in High-Risk Pregnant Women.

BACKGROUND: This prospective study aimed to determine maternal clinical, laboratory, and ultrasound findings that effectively predict the occurrence of congenital cytomegalovirus (CMV) infection (CCI) in high-risk pregnant women. METHODS: Three hundred CMV immunoglobulin (Ig) M-positive pregnant women were enrolled. The maternal clinical and laboratory findings, including serum CMV IgM and IgG; IgG avidity index (AI); antigenemia assay (C7-HRP); polymerase chain reaction (PCR) for the detection of CMV-DNA in the maternal serum, urine, and uterine cervical secretion; and prenatal ultrasound findings, were evaluated. To determine predictive factors for the occurrence of CCI, logistic regression analyses were performed. RESULTS: In 22 of the 300 women, CCI was confirmed using PCR for CMV-DNA in newborn urine. Univariate analyses demonstrated that the presence of maternal flu-like symptoms, presence of ultrasound fetal abnormalities, serum titers of CMV IgM, positive results for C7-HRP, CMV IgG AI <40%, and positive PCR results in the uterine cervical secretion were statistically associated with the occurrence of CCI. Multivariable analysis revealed that the presence of ultrasound fetal abnormalities (odds ratio [OR], 31.9; 95% confidence interval [CI], 8.5-120.3; P < .001) and positive PCR results in the uterine cervical secretion (OR, 16.4; 95% CI, 5.0-54.1; P < .001) were independent predictive factors of CCI in CMV IgM-positive women. CONCLUSIONS: This is the first prospective cohort study to suggest that the presence of CMV-DNA in the maternal uterine cervical secretion and ultrasound fetal abnormalities are predictive of the occurrence of congenital CMV infection in high-risk pregnant women.

Current status of non-invasive prenatal testing in Japan.

AIM: The purpose of this study was to report the 3-year experience of a nationwide demonstration project to introduce non-invasive prenatal testing (NIPT) of maternal plasma for aneuploidy, and review the current status of NIPT in Japan. METHODS: Tests were conducted to detect aneuploidy in high-risk pregnant women, and adequate genetic counseling was provided. The clinical data, test results, and pregnancy outcomes were recorded. We discuss the problems of NIPT on the basis of published reports and meta-analyses. RESULTS: From April 2013 to March 2016, 30 613 tests were conducted at 55 medical sites participating in a multicenter clinical study. Among the 30 613 women tested, 554 were positive (1.81%) and 30 021 were negative (98.1%) for aneuploidy. Of the 289, 128, and 44 women who tested positive for trisomies 21, 18, and 13, respectively, and underwent definitive testing, 279 (96.5%), 106 (82.8%), and 28 (63.6%) were determined to have a true-positive result. For the 13 481 women with negative result and whose progress could be traced, two had a false-negative result (0.02%). The tests were performed on the condition that a standard level of genetic counseling be provided at hospitals. CONCLUSION: Here, we report on the 3-year nationwide experience with NIPT in Japan. It is important to establish a genetic counseling system to enable women to make informed decisions regarding prenatal testing. Moreover, a welfare system is warranted to support women who decide to give birth to and raise children with chromosomal diseases.

A survey on awareness of genetic counseling for non-invasive prenatal testing: the first year experience in Japan.

The purpose of this study is to summarize the results from a survey on awareness of genetic counseling for pregnant women who wish to receive non-invasive prenatal testing (NIPT) in Japan. As a component of a clinical study by the Japan NIPT Consortium, genetic counseling was conducted for women who wished to receive NIPT, and a questionnaire concerning both NIPT and genetic counseling was given twice: once after pre-test counseling and again when test results were reported. The responses of 7292 women were analyzed. They expressed high satisfaction with the genetic counseling system of the NIPT Consortium (94%). The number of respondents who indicated that genetic counseling is necessary for NIPT increased over time. Furthermore, they highly valued genetic counseling provided by skilled clinicians, such as clinical geneticists or genetic counselors. The vast majority (90%) responded that there was sufficient opportunity to consider the test ahead of time. Meanwhile, women who received positive test results had a poor opinion and expressed a low-degree satisfaction. We confirmed that the pre-test genetic counseling that we conducted creates an opportunity for pregnant women to sufficiently consider prenatal testing, promotes its understanding and has possibilities to effectively facilitate informed decision making after adequate consideration. A more careful and thorough approach is considered to be necessary for women who received positive test results.

A novel PIGN mutation and prenatal diagnosis of inherited glycosylphosphatidylinositol deficiency.

Glycosylphosphatidylinositol (GPI) anchors tether proteins to the extracellular face of eukaryotic plasma membranes. Defects in the human GPI anchor biosynthetic pathway cause inherited GPI deficiencies (IGDs) characterized by multiple congenital anomalies: dysmorphic faces, developmental delay, hypotonia, and epilepsy. We report the case of a 6-year-old boy with severe psychomotor developmental delay, epilepsy, and decreased granulocyte surface expression of GPI-anchored protein that suggested autosomal recessive GPI deficiency. The case underwent target exome sequencing to screen for IGDs. Target exome sequencing of the proband identified an apparently homozygous c.808T > C (p.Ser270Pro) mutation in PIGN, a gene involved in the GPI anchor biosynthetic pathway. As his parents were expecting another child, genetic carrier screening was conducted for the parents. Direct sequencing of the parents identified a heterozygous c.808T > C PIGN mutation in the father but none in the mother. To identify the mother's mutation, we performed semi-quantitative real-time PCR of the PIGN exons and long PCR, identifying a microdeletion in PIGN (del exons 2-14). The proband had inherited this microdeletion from his mother. Prenatal diagnosis of the fetus revealed that it was a heterozygous carrier of the mother's pathogenic allele. Here, we report a sporadic case of inherited GPI deficiency with a PIGN mutation and the first case of prenatal diagnosis for GPI deficiency.

Nationwide survey of mother-to-child infections in Japan.

OBJECTIVES: The aim of this survey study was to evaluate a state of mother-to-child infections in Japan. METHODS: A nationwide survey on 2714 obstetric facilities where regular maternity checkups were carried out was conducted. A primary questionnaire assessed numbers of pregnancies including induced abortion, spontaneous abortion, still-birth as well as live-birth, which were affected by congenital infections of 6 pathogens during a year of 2011. The secondary questionnaire assessed clinical information, diagnostic modality, and the outcome for each case. The clinical features and diagnostic problems were evaluated. RESULTS: The high reply rates for the primary (73.7%) and the secondary questionnaire (100%) were achieved. The presence of congenital infections for 34 cases with cytomegalovirus (CMV), 1 with Toxoplasma gondii, 4 with rubella virus, 5 with Treponema pallidum, 8 with herpes simplex virus, and 69 with parvovirus B19 was confirmed after questionnaire assessment. The incidence of fetal demise among pregnancies with congenital parvovirus B19 infection was up to 71.0%. Eleven mothers with hydrops fetalis received prenatal fetal therapies involving fetal blood transfusion and immunoglobulin administration, whereas only three pregnancies (27.3%) ended in live-births. CONCLUSIONS: This survey study for the first time revealed the annual frequency of pregnancies with mother-to-child infections of 6 pathogens in Japan. The results involve important information and are helpful for clinical practitioners. The majority of neonates with congenital infection of CMV or T. gondii might be undiagnosed in obstetric facilities.

The IgG avidity value for the prediction of Toxoplasma gondii infection in the amniotic fluid.

Primary Toxoplasma gondii (T. gondii) infection during pregnancy may lead to congenital toxoplasmosis. Maternal screening using T. gondii IgG avidity measurement and multiplex nested PCR was performed. The aim of this prospective cohort study was to determine a cut-off value of IgG avidity index (AI) for the prediction of the presence of T. gondii DNA in the amniotic fluid. One hundred thirty-nine women with positive or equivocal tests for IgM underwent both serum IgG avidity measurement and PCR analysis for the amniotic fluid. Nine had positive PCR results, and three of them were diagnosed as having congenital infection. A cut-off value of IgG AI was determined using receiver operating characteristic analysis. IgG AI (mean 13%) in women with positive PCR results was significantly lower than that (39%) in women with negative results. A cut-off value of <25% IgG AI yields the best results with 77.8% sensitivity and 81.5% specificity for the presence of T. gondii DNA in the amniotic fluid. None of women with IgG AI of ≥30% had a positive PCR result or congenital infection. This study firstly demonstrated that a cut-off value of 25-30% IgG AI might be useful for the prediction of the presence of T. gondii DNA in the amniotic fluid and congenital infection.

The IgG avidity value for the prediction of congenital cytomegalovirus infection in a prospective cohort study.

BACKGROUND: Cytomegalovirus (CMV) causes congenital infection with high mortality and morbidity rates in affected neonates. OBJECTIVES: To evaluate the maternal IgG avidity value for the prediction of congenital CMV infection. STUDY DESIGN: The serum IgG avidity in all mothers was measured, and the urine of their neonates was assessed for CMV DNA in a prospective cohort study. RESULTS: Of 759 women with a positive test for CMV IgG, 14 had congenital CMV infection. CMV IgG avidity indices in the congenital infection group (median 35.1%) were significantly lower than those in the non-congenital infection group (70.4%). A cutoff value of <40% IgG avidity index with 96.1% specificity and 64.3% sensitivity for congenital infection was determined by receiver operating characteristic curve analyses. The highest sensitivity (88.9%), 96.2% specificity, 27.6% positive predictive value, 99.8% negative predictive value, and 96.1% accuracy were found when IgG avidity was measured in <28 weeks of gestation. CONCLUSION: The IgG avidity measurement with a cutoff value of <40% IgG avidity index might be helpful in predicting congenital CMV infection, especially in <28 weeks of gestation.

Fetal Ultrasound and Magnetic Resonance Imaging Abnormalities in Congenital Cytomegalovirus Infection Associated with and without Fetal Growth Restriction.

Congenital cytomegalovirus infection (cCMV) can cause fetal growth restriction (FGR) and severe sequelae in affected infants. Clinicians generally suspect cCMV based on multiple ultrasound (US) findings associated with cCMV. However, no studies have assessed the diagnostic accuracy of fetal US for cCMV-associated abnormalities in FGR. Eight FGR and 10 non-FGR fetuses prenatally diagnosed with cCMV were examined by undergoing periodic detailed US examinations, as well as postnatal physical and imaging examinations. The diagnostic accuracy of prenatal US for cCMV-associated abnormalities was compared between FGR and non-FGR fetuses with cCMV. The diagnostic sensitivity rates of fetal US for cCMV-related abnormalities in FGR vs. non-FGR fetuses were as follows: ventriculomegaly, 66.7% vs. 88.9%; intracranial calcification, 20.0% vs. 20.0%; cysts and pseudocysts in the brain, 0% vs. 0%; ascites, 100.0% vs. 100.0%; hepatomegaly, 40.0% vs. 100.0%; splenomegaly, 0% vs. 0%. The diagnostic sensitivity of fetal US for hepatomegaly and ventriculomegaly in FGR fetuses with cCMV was lower than that in non-FGR fetuses with cCMV. The prevalence of severe long-term sequelae (e.g., bilateral hearing impairment, epilepsy, cerebral palsy, and severe developmental delay) in the CMV-infected fetuses with FGR was higher, albeit non-significantly. Clinicians should keep in mind the possibility of overlooking the symptoms of cCMV in assessing fetuses with FGR.

Low IgG avidity and ultrasound fetal abnormality predict congenital cytomegalovirus infection.

Cytomegalovirus (CMV) causes congenital infection with high mortality and morbidity rates in affected neonates. The aim of this study was to assess whether prenatal clinical or laboratory findings in pregnant women who had high risks for primary CMV infection predicted the presence of congenital infection. Fifty pregnant women who had serum CMV IgG and positive or borderline tests for serum CMV IgM were included in this prospective study. Serum IgG avidity was measured, and PCR was conducted for CMV DNA in maternal serum, urine, and uterine cervical secretion. All neonates underwent PCR testing for CMV DNA in the urine for the presence of congenital infection. Risk factors were compared between congenital infection group and group without congenital infection. As a result, nine neonates (18%) were diagnosed as having congenital infection. The frequencies of ultrasound fetal abnormality and positive test for CMV DNA in cervical secretion, CMV IgM titer and IgM/IgG ratio in the congenital infection group were significantly higher than those in the group without congenital infection. Conversely, IgG avidity index in the congenital infection group was significantly lower than that in the group without congenital infection. By multivariate logistic regression analyses, IgG avidity index (Odds ratio 0.91, 95% CI: 0.83-0.99) and ultrasound fetal abnormality (291.22, 2.72-31125.05), were selected independently as significant signs predictive of congenital CMV infection. Among pregnant women with positive or borderline tests for CMV IgM, when they have findings of low serum CMV IgG avidity or ultrasound fetal abnormality, the probability of congenital CMV infection may increase.

Prospective study of congenital toxoplasmosis screening with use of IgG avidity and multiplex nested PCR methods.

Acute infection with Toxoplasma gondii during pregnancy can cause congenital toxoplasmosis. The aim of this study was to evaluate whether screening with the use of IgG avidity and multiplex nested PCR methods was effective to detect a high-risk pregnancy. In a prospective study, serum T. gondii IgG avidity was measured in consecutive 146 pregnant women testing positive for T. gondii antibody and either positive or equivocal for IgM. Multiplex nested PCR for T. gondii DNA on amniotic fluid, maternal blood, and umbilical cord blood were performed with informed consent. A total of 51 (34.9%) women presented with low IgG avidity (<30%), 15 (10.3%) presented with borderline avidity (30 to 35%), and 80 (54.8%) presented with high avidity (>35%) indices. Amniotic fluid obtained at amniocentesis or birth yielded positive PCR results in nine women with low IgG avidity indices. Of these nine women, three had congenital toxoplasmosis. None of women with high or border line IgG avidity indices had a positive PCR result in the amniotic fluid or congenital toxoplasmosis. No congenital toxoplasmosis was detected in women whose amniotic fluids yielded negative PCR results. Ingestion of raw or undercooked meat was found to be the main risk factor for acute T. gondii infection. Congenital toxoplasmosis screening with a combination of IgG avidity in the maternal blood and multiplex nested PCR in the amniotic fluid was useful for detecting a high risk pregnancy and diagnosing congenital toxoplasmosis.