Changing epidemiology of parvovirus B19 in the Netherlands since 1990, including its re-emergence after the COVID-19 pandemic.

Parvovirus B19V (B19V) infection during pregnancy can be complicated by potentially life-threatening fetal hydrops, which can be managed by intrauterine transfusion (IUT). This study investigates the long-term temporal patterns in the epidemiology of B19V and evaluates the impact on fetal hydrops, by combining data on B19V infections from the Dutch Sentinel Surveillance system in the period 1990 to 2023, Dutch blood banking data and hospital data on fetal hydrops. Using wavelet analysis, we identified annual epidemic cycles in the Netherlands in the period 1990-2019 and we identified superimposed multiannual cycles in the period 1990-2009. After 2009, no multiannual cycle could be identified, although the incidence fluctuated and correlates with number of IUT performed. As of 2020, weekly reports of B19V infection demonstrated a historically low incidence and B19V-DNA positive blood donors were nearly absent. From May 2020 to May 2023, no IUT for B19V-related hydrops was performed. In the spring of 2023, B19V infections re-emerged, reaching pre-pandemic epidemic levels. Due to the changes in B19V epidemiology over the last 30 years and the near-absence of B19V during the COVID-19 pandemic, the resulting low immunity levels may lead to rebound outbreaks. Alertness to severe complications such as fetal hydrops is warranted.

Maternal outcomes of a cohort of pregnancies affected by non-immune hydrops fetalis.

OBJECTIVE: To describe the maternal outcomes of a prospective cohort of non-immune hydrops fetalis (NIHF) pregnancies with negative standard-of-care evaluations. METHODS: This study was a secondary analysis of a prospective cohort study of NIHF pregnancies with negative work-ups (infection, alloimmune anemia, fetomaternal hemorrhage, and chromosomal disorders). Outcomes were obstetric complications, including pre-eclampsia, mirror syndrome, preterm birth, polyhydramnios, postpartum hemorrhage, and maternal mental health. RESULTS: Forty pregnancies were included. Four patients developed pre-eclampsia (4/40, 10.0%); three occurred postpartum. None was diagnosed with mirror syndrome. Of the 31 continued pregnancies, 16 (51.6%) resulted in early fetal death or stillbirth and 15 (48.4%) resulted in live births. Of the 15 live births, 8 (53.3%) were delivered by primary cesarean delivery; 5 (62.5%) were for hydrops fetalis. Eleven live births (73.3%) were delivered preterm; 9 (81.8%) were indicated, most commonly for fetal indications (7/9, 77.8%). Polyhydramnios occurred in 14/40 (35.0%) cases. Where EBL was recorded (n=37), there were 5 (13.5%) cases of postpartum hemorrhage and an additional 3 (8.1%) had uterine atony without hemorrhage. Eighteen patients (18/40, 45.0%) had new-onset or exacerbated depression or anxiety symptoms. CONCLUSION: Our study identified several important adverse outcomes of pregnancies complicated by NIHF with negative standard-of-care evaluations, including a high rate of postpartum pre-eclampsia and worsened mental health. We identified a higher rate of cesarean delivery and preterm birth, both primarily for fetal indications. We also observed the known relationship between polyhydramnios, hemorrhage, and atony, but noted that this risk included pregnancies concluding in dilation and evacuation. Counseling after a diagnosis of NIHF should include these adverse outcomes.

Postnatal Outcomes in Infants With a History of Fetal Supraventricular Tachycardia.

BACKGROUND: Fetal supraventricular tachycardia (SVT) is rare and proposed predictors of postnatal outcomes in fetal SVT have not been validated. Valid predictors can guide postnatal management. OBJECTIVES: The authors correlated fetal characteristics to the incidence of postnatal SVT and compared SVT outcomes in infants with and without a history of fetal SVT. METHODS: Mother-fetus dyads with fetal SVT and a structurally normal heart were described and compared with a second cohort of infants with a postnatal diagnosis of SVT. RESULTS: SVT was observed in 78 fetuses and 76 survived to delivery. Maternally administered transplacental antiarrhythmics were used in 49 mother-fetus dyads. Rhythm control was achieved in 37 of 49 (76%). Among fetuses with intermittent SVT, there was no ventricular dysfunction or hydrops. Postnatal SVT occurred in one-half of infants (37 of 76), and 94% presented within the first 2 days of life. The following fetal characteristics were associated with postnatal SVT on univariable analysis: sustained SVT (87% vs 56%), ventricular dysfunction (41% vs 15%), lack of conversion to sinus rhythm (49% vs 10%), and earlier gestational age at delivery (37.6 weeks vs 38.9 weeks; P ≤ 0.01 for each comparison). Compared with infants with a postnatal diagnosis of SVT, infants with a fetal diagnosis presented earlier (median age 0 days vs 17 days; P < 0.01) and had a lower incidence ventricular dysfunction at presentation (5% vs 42%; P < 0.01). CONCLUSIONS: One-half of infants with fetal SVT had postnatal SVT, nearly all within 2 days of life. These data and predictors of postnatal SVT may influence parental counseling and postnatal clinical decision-making.

A single center experience in 90 cases with nonimmune hydrops fetalis: diagnostic categories ‒ mostly aneuploidy and still often idiopathic.

OBJECTIVES: The prognosis of nonimmune hydrops fetalis (NIHF) is still poor with a high mortality and morbidity rate despite progress in perinatal care. This study was designed to investigate etiology and outcome of NIHF. METHODS: A retrospective review of 90 NIHF cases from 2007 to 2019 was conducted at University Medical Center of the Johannes Gutenberg University, Mainz, Germany. Demographics, genetic results, prenatal and postnatal outcomes including one year survival as well as autopsy data were extracted. Etiology of hydrops was classified using 13 previously established categories. In 4 patients observed between 2016 and 2019, we used a next-generation-sequencing (NGS) panel for genetic evaluation. RESULTS: Ninety NIHF cases were identified, with a median gestational age (GA) at diagnosis of 14 weeks. There were 25 live-born infants with a median GA of 34 weeks at birth, 15 patients survived to one year. There was aneuploidy in more than one third of the cases. All 90 cases were subclassified into etiologic categories with chromosomal 35, idiopathic 15, syndromic 11, cardiovascular 9, inborn errors of metabolism 6, lymphatic dysplasia 3, thoracic 3, infections 3, gastrointestinal 3 and hematologic 2. The NGS panel was used in 4 cases and 4 diagnoses were made. CONCLUSIONS: In 90 cases with NIHF we identified an aneuploidy in more than one third of the cases. Improved techniques, such as possibly specific genetic analysis, could reduce the high rate of unexplained cases of NIHF.

Hydrops fetalis-trends in associated diagnoses and mortality from 1997-2018.

OBJECTIVES: To describe and evaluate trends in the etiology and mortality risk in neonates admitted for neonatal intensive care with hydrops fetalis. STUDY DESIGN: A retrospective review of de-identified patient data in the Pediatrix Clinical Data Warehouse from 1997 to 2018. RESULTS: We identified 2144 infants diagnosed with hydrops fetalis. The most common diagnoses were congenital heart disease (n = 325, 15.2%), genetic diagnoses (n = 269, 12.5%) and cardiac arrhythmia (n = 176, 8.2%). Of 2144 neonates, 988 (46%) survived to hospital discharge and 775 (36%) died prior to discharge. Mortality rate was highly variable across diagnoses, ranging from 90% in infants with congenital diaphragmatic hernia to 0% in infants with atrial flutter. Over the study period, more infants were diagnosed with trisomies and fewer with twin-to-twin transfusion. Mortality decreased by 5% from 1997-2007 to 2008-2018. CONCLUSIONS: The risk of death among neonates with hydrops fetalis is highly dependent on the underlying cause, with increasing risk of mortality at lower gestational ages.

Lysosomal storage disorders as an etiology of nonimmune hydrops fetalis: A systematic review.

We performed a systematic review of the literature to evaluate the incidence and types of lysosomal storage disorders (LSD) in case series of nonimmune hydrops fetalis (NIHF). PubMed, Ovid, and clinicaltrials.gov were reviewed for case series evaluating the workup of NIHF diagnosed in utero or in the neonatal period in human subjects from 1979 to August 2020. Retrospective case series with at least five cases of fetal and/or neonatal NIHF with its workup mentioned were identified. Idiopathic NIHF was defined as NIHF without an apparent cause after initial standard-of-care workup. In total, 22 case series with 2678 total cases of NIHF were identified. The overall incidence of LSD was 6.6% (177/2663) in NIHF cases that were tested for any LSD, and 8.2% (177/2151) in idiopathic NIHF cases. The most common LSD identified in cases of NIHF were mucopolysaccharidosis type VII, galactosialidosis, infantile sialic acid storage disease, Gaucher disease, GM1 gangliosidosis, and sialidosis. More than 40% of the most common LSD causes of NIHF have a potential postnatal treatment. LSD testing for NIHF allows for early diagnosis, better counseling and appropriate management, planning for possible early treatment, and counseling for recurrence risk.

Outcomes following the detection of fetal edema in early pregnancy prior to non-invasive prenatal testing.

OBJECTIVE: To investigate the incidence of structural and chromosomal abnormalities in cases of fetal edema on early ultrasound prior to non-invasive prenatal testing (NIPT). METHODS: A retrospective study of women undergoing pre-NIPT ultrasound with fetal crown-rump length (CRL) of 28 to 44 mm was conducted at a tertiary obstetric ultrasound clinic in Melbourne, Australia. Cases of reported fetal edema were included, and subclassified as isolated nuchal edema (>2.2 mm) or generalized edema/hydrops by two operators blinded to outcomes. RESULTS: We identified 104 cases of fetal edema. Nuchal edema and generalized edema were present in 40 (38.5%) and 64 (61.5%) cases, respectively. Relevant chromosomal anomalies were identified in 19.2% (20/104), occurring in 10.0% (4/40) of the nuchal edema and 25.0% (16/64) of the generalized edema/hydrops cases. Structural anomalies with normal karyotype occurred in four (3.8%) additional cases. Miscarriage occurred in four cases (3.8%) and termination of pregnancy in 18 cases (17.3%). Among cases that reached the 11 to 13+6 weeks ultrasound, the edema resolved in 81.9% and these cases had less adverse outcomes than those with NT≥3.5 mm (10.9% vs 76.5%, P < .001). CONCLUSIONS: Fetal edema in early pregnancy is associated with a high incidence of structural and/or chromosomal abnormalities; these rates increase with progressive severity.

Prenatal Imaging to Predict Need for Urgent Perinatal Surgery in Congenital Lung Lesions.

BACKGROUND: Congenital lung malformations (CLMs) have a variable natural history: some patients require urgent perinatal surgical intervention (UPSI) and others remain asymptomatic. These lesions have potential growth until 26-28 wk gestation. CLM volume ratio (CVR) has been shown to predict the risk of hydrops in CLMs. However, no criteria exist to delineate lesions requiring urgent surgical intervention in the perinatal period. Our goal was to determine prenatal diagnostic features that predict the need for UPSI in patients diagnosed with CLM. METHODS: Records and imaging features of all fetuses evaluated by our fetal center between May 2015 and December 2018 were retrospectively reviewed. Data included demographics, fetal ultrasound and magnetic resonance imaging, CVR, surgical treatment, and outcome. Features were analyzed for their ability to predict the need for UPSI. RESULTS: Sixty-four patients were referred for CLM, with 48 patients serially followed. Nine (18.8%) patients were followed nonoperatively, 35 (72.9%) underwent resection, and four (8.3%) were lost to follow-up. Of the patients who underwent resection, 24 (68.5%) were electively resected and 11 were urgently resected. Five (14.3%) patients underwent ex utero intrapartum treatment resection, and six (17.1%) were urgently resected for symptomatic CLM. There were no cases of UPSI with final CVR <1.1. Of the patients with final CVR 1.1-1.7, 43% required urgent resection. CVR ≥1.1 has 100% sensitivity and 87.8% specificity to predict patients requiring UPSI (area under the curve of 0.98). CONCLUSIONS: A final CVR ≥1.1 is highly predictive for UPSI. Patients with a final CVR ≥1.1 should be referred for delivery at centers with pediatric surgeons equipped for potential UPSI for CLM.

Nonimmune hydrops fetalis: Genetic analysis and clinical outcome.

OBJECTIVE: To investigate the genetic causes and clinical outcomes of nonimmune hydrops fetalis (NIHF). METHODS: Cohort of cases of NIHF between July 2013 and December 2018. Initial genetic testing included quantitative fluorescence polymerase chain reaction for aneuploidies, karyotyping and chromosomal microarray analysis (CMA). In negative results, whole exome sequencing (WES) of the fetuses and parents was performed. Clinical post-natal follow-up assessments were conducted. RESULTS: One hundred and nine patients fulfilled the study inclusion criteria and were sequentially genetically assessed by karyotype, CMA and WES. Among them, 24.8% (27/109) had a clinically significant genetic abnormality: 21 (19%) had abnormal karyotypes; 3/72 had pathogenic/likely pathogenic copy number variants (additional yield = 4.2%); and 3 had single gene disorders. The pregnancy termination and live birth rates of the cases with positive genetic testing results were significantly different from those with negative results (92.6% vs 53.7% and 3.7% vs 31.7%, respectively, P < .05 for both). During clinical follow-up of the survivors, 3/23 (13.0%) children developed an additional phenotype. CONCLUSION: This study improves our understanding of the diagnostic yield of CMA and WES for NIHF. A genetic diagnosis of NIHF can help determine the fetal prognosis and recurrence risk and influence pregnancy decision-making.

Non-immune hydrops fetalis was rare in Sweden during 1997-2015, but cases were associated with complications and poor prognosis.

AIM: The study was designed to document the incidence of non-immune hydrops fetalis (NIHF) at birth and characterise associated outcomes and obstetric complications. METHODS: Data on more than 1.9 million births were extracted from the Swedish Birth Register for 1997-2015. Pregnancies not affected by NIHF served as controls. National registers on mortality and hospitalisations provided follow-up information. RESULTS: There were 309 cases of NIHF at birth corresponding to an incidence of 1.6 per 10 000, lower than in previous studies. NIHF was more frequent in mothers aged ≥35 years and with a history of stillbirth. Preterm delivery occurred in 77.7% in the NIHF group, including 31.7% before 32 weeks of gestation. Multiple births and Caesarean sections were reported more frequent in the NIHF group. NIHF was associated with poor outcome with 14.6% stillbirths and in 26.5% early neonatal death. Overall, 58.7% of live-born children with NIHF were alive at 12 months compared with 99.7% of controls. The most common causes of death were cardiovascular diseases and thoracic abnormalities. CONCLUSION: NIHF at birth is associated with obstetric complications and poor prognosis for the neonate related to underlying disease. The low incidence of NIHF observed in this study may reflect well-developed antenatal care.

Hydrops fetalis in a cohort of 3,137 stillbirths and second trimester miscarriages.

Hydrops fetalis was diagnosed in 277 (9%) of 3,137 fetuses referred to the Wisconsin Stillbirth Service Program (WiSSP) for etiologic evaluation of stillbirth or second trimester miscarriage. Hydrops was clinically recognized at delivery in only about half the cases, while the remainder were diagnosed at autopsy or during evaluation of records, photographs, and radiographs. The peak incidence of hydrops was at 20-28 weeks. Hydropic fetuses were also frequent before 20 weeks but became increasingly rare toward term. The most frequent identifiable underlying cause was chromosomal (29%), followed by other syndromes (14%), and more distantly by cardiac (6%) and other single system disorders. While the overall prevalence of hydrops and chromosomal causes was comparable to other autopsy series, the frequency of nonchromosomal syndromes was higher, reflecting increased attention to syndrome identification. Lethal multiple pterygium syndrome (LMPS) was identified retrospectively in 17 cases, accounting for 6% of all hydrops; 3/17 had a previous affected sib, emphasizing the importance of accurate diagnosis and counseling. Depending on the underlying cause, hydropic fetuses may be either small (if the cause is chromosomal or LMPS) or large (in cases with other syndromes or cardiac causes) for gestational age. The relatively large number in the "idiopathic" group in WiSSP (104/277; 38%) is probably due to variability of autopsies at local hospitals and limited laboratory data. Improved recognition of hydrops and testing directed at diagnosis of specific underlying causes can lead to improved counseling for families.

Etiology and Outcome of non-immune Hydrops Fetalis in Southern China: report of 1004 cases.

Non-immune hydrops fetalis (NIHF) is a complex condition with a high mortality and morbidity rate. Here we report the etiology and outcome of 1004 fetuses with NIHF, in a large single Maternal and Children's hospital of Southern China, since the year of 2009 to 2016. Among these 1004 fetuses with NIHF, the etiology was identified prenatally in 722 of them (72%). The most common ones were hematologic diseases and chromosomal abnormalities. There were eight spontaneous abortions, 18 intrauterine fetal demise, 672 pregnancy terminations and 87 were lost to follow-up. 219 of the 1004 fetuses were live-born and the overall survival rate was 21.8% at this point. After birth 16 perinatal or early neonatal deaths were encountered and five lost to follow-up. Of the remaining 198 newborns, 153 thrived without apparent morbidity. The most significant factors associated with mortality were prematurity and low birthweight. In conclusion, we described the largest report of underlying causes and outcome of NIHF in Southern China. Etiologies were identified for 72% of 1004 fetuses with NIHF. And two poor prognostic factors for survival are preterm birth at less than 36.5 weeks and birthweight lower than 2575 g respectively.

Molecular characteristics of thalassemia and hemoglobin variants in prenatal diagnosis program in northern Thailand.

Molecular analysis of globin genes is an essential process for prenatal diagnosis (PND) of severe thalassemia. This study aimed to describe the molecular characteristics of thalassemia and hemoglobin (Hb) variants in PND program in northern Thailand. The type and frequency of globin gene mutations from 1290 couples at risk of fetal severe thalassemia diseases that were tested at Thalassemia Laboratory at Chiang Mai University from 2012 to 2017 were retrospectively reviewed. The PND program detected 444 (34.4%), 196 (15.2%) and 642 (49.8%) couples at risk of fetal Hb Bart's hydrops fetalis, beta-thalassemia major (BTM) and beta-thalassemia/Hb E disease, respectively. Coinheritance of more than one type of thalassemia was common and eight (0.6%) couples were at risk of two types of severe thalassemia. There were two types of alpha0-thalassemia; 893 (99.7%) Southeast Asian and 3 (0.3%) Thai deletions. Twenty beta-globin gene mutations were found with 94.3% of beta0-thalassemia. The codon 41/42 (- TTCT), codon 17 (A>T), IVS-I-1 (G>T) and codon 71/72 (+ A) comprised 90% of beta-thalassemia mutations. The study shows a high percentage of couples at risk of fetal Hb Bart's hydrops fetalis and BTM. The percentage of beta0-thalassemia is higher than those seen in other regions of Thailand.

Predisposing factors and neonatal outcomes for twin-twin transfusion syndrome cases developing transient donor hydrops after fetoscopic laser coagulation: a case control study.

BACKGROUND: Transient donor hydrops (TDH) is defined as donor hydrops developed within days after laser therapy for twin-twin transfusion syndrome (TTTS) followed by resolution later. The purpose of this study was to evaluate the incidence, neonatal outcomes and predisposing factors of post laser therapy TDH in severe TTTS. METHODS: A total of 142 patients with severe TTTS who received laser therapy were included into this study. The pre-operative characteristics and neonatal outcomes were compared between TTTS with and without post laser therapy TDH. All live neonates received cranial ultrasound examination after delivery, mild cerebral injury was defined as exhibiting at least one of the following: intraventricular hemorrhage (IVH) grade I and II, lenticulostriate vasculopathy and subependymal pseudocysts; severe cerebral injury comprised at least one among the following: IVH grade III or grade IV, cystic periventriculoleukomalacia (PVL) grade II or more, porencephalic cysts, and ventricular dilatation. Fetal survival was defined as living more than 30 days after delivery.

Fetal hydrops and the risk of severe preeclampsia.

OBJECTIVE: To assess the incidence and severity of preeclampsia in pregnancies complicated by fetal hydrops. METHODS: We performed a retrospective cohort study of singleton gestations from 2005 to 2008 in California. The primary predictor was fetal hydrops and the primary outcome was preeclampsia. Selected adverse maternal and neonatal events were assessed as secondary outcomes. Potential confounders examined included fetal anomalies, polyhydramnios, race/ethnicity, nulliparity, chronic hypertension, and gestational or pregestational diabetes mellitus. RESULTS: We identified 337 pregnancies complicated by fetal hydrops, 70.0% had a concomitant fetal anomaly and 39.8% had polyhydramnios. Compared to the general population, hydrops was associated with an increased risk for severe preeclampsia (5.26 versus 0.91%, p < .001) but not mild preeclampsia (2.86 versus 2.02%, p = .29). In multivariable analysis, fetal hydrops remained an independent risk factor for severe preeclampsia (as adjusted odds ratios (aOR) 3.13, 1.91-5.14). Hydrops was also associated with increased rates of eclampsia, acute renal failure, pulmonary edema, postpartum hemorrhage, blood transfusion, preterm birth, and neonatal death. CONCLUSIONS: We find that fetal hydrops is an independent risk factor for severe preeclampsia. In light of serious concerns for maternal and neonatal health, heightened surveillance for signs and symptoms of severe preeclampsia is warranted in all pregnancies complicated by fetal hydrops.

Inborn errors of metabolism in a cohort of pregnancies with non-immune hydrops fetalis: a single center experience.

OBJECTIVE: The purpose of this study was to determine the frequency of non-immune hydrops fetalis (NIHF) among all pregnancies referred for prenatal care at Sultan Qaboos University Hospital (SQUH) during the study period and to evaluate the underlying etiologies of NIH. STUDY DESIGN: All pregnancies referred to SQUH between February 2014 and December 2015 were identified, and all pregnancies meeting the diagnosis of NIHF were included in this study. All cases of NIHF referred to our center during this period underwent standard systematic diagnostic work-up that included biochemical and molecular studies in addition to the standard investigations for hydrops fetalis. Clinical characteristics and results of the diagnostic work-up were retrospectively reviewed. RESULTS: A total of 3234 pregnancies were referred for prenatal care at SQUH during the study period, and 12 pregnancies were affected by NIHF. An underlying diagnosis was established in nine cases, and the majority of cases (7/9) were caused by inborn errors of metabolism (IEM). These included a novel homozygous variant in the AARS2 gene (5/7) and two cases of galactosialidosis (2/7). CONCLUSION: IEM was a major cause of NIHF in this cohort. The AARS2 variant accounts for a significant number of cases with NIHF in this cohort of Omani patients.

Non-Immune Hydrops Fetalis: Do Placentomegaly and Polyhydramnios Matter?

OBJECTIVES: Polyhydramnios and placentomegaly are commonly observed in nonimmune hydrops fetalis (NIHF); however, whether their ultrasonographic identification is relevant for prognosis is controversial. We evaluated outcomes of fetal or neonatal death and preterm birth (PTB) in cases of NIHF alone and in those with polyhydramnios and/or placentomegaly (P/PM). METHODS: We conducted a retrospective cohort of singletons with NIHF evaluated between 1994 and 2013. Nonimmune hydrops fetalis was defined as 2 or more abnormal fluid collections, including ascites, pericardial effusion, pleural effusion, and skin edema. Primary outcomes were intrauterine fetal demise (IUFD) and neonatal death. Secondary outcomes were PTB (<37, < 34, and <28 weeks) and spontaneous PTB. Outcomes were compared between cases of NIHF alone and NIHF with P/PM. RESULTS: A total of 153 cases were included; 21% (32 of 153) had NIHF alone, and 79% (121 of 153) had NIHF with P/PM. There was no significant difference in neonatal death (38.1% versus 43.0%; P = .809) between the groups. Intrauterine fetal demise was seen more frequently in NIHF alone (34.4% versus 17.4%; P = .049). Nonimmune hydrops fetalis-with-P/PM cases were more likely to deliver before 37 weeks (80.0% versus 57.1%; P = .045) and before 34 weeks (60.0% versus 28.6%; P = .015) and to have spontaneous PTB (64.4% versus 33.3%; P = .042). Adjusted odds ratios accounting for the etiology of NIHF supported these findings, with the exception of IUFD. CONCLUSIONS: Compared to NIHF alone, pregnancies with NIHF and P/PM had a lower risk of IUFD and were at increased risk of PTB (<37 and <34 weeks) and spontaneous PTB. This information may help providers in counseling patients with NIHF and supports the need for close antenatal surveillance.

Epidemiology of Live Born Infants with Nonimmune Hydrops Fetalis-Insights from a Population-Based Dataset.

OBJECTIVE: To evaluate the incidence, etiology, and 1-year mortality of nonimmune hydrops fetalis (NIHF) and to identify risk factors for mortality in a contemporary population-based dataset. STUDY DESIGN: The California Office of Statewide Health Planning and Development maintains a database linking maternal and infant hospital discharge, readmissions, and birth and death certificate date from 1 year before to 1 year after birth. We searched the database (2005-2012) for infants with NIHF (identified by the International Classification of Diseases, 9th Revision, Clinical Modification code). Hazard models were used to identify risk factors for mortality in infants with NIHF; results are presented as hazard ratios (HRs, 95% CI). RESULTS: The incidence of NIHF was 2.5 out of 10 000 among live born infants. Neonatal mortality was 35.1% (364 out of 1037) and overall mortality was 43.2% (448 out of 1037) at 1 year of age. Gestational age (GA) was predictive of mortality with a HR of 2.4 (95% CI 1.9-3.2) for preterm compared with term infants. The GA-adjusted HR for mortality was 1.3 (95% CI 1.1-1.6) for polyhydramnios and 1.5 (95% CI 1.2-2.0) for large for gestational age infants compared with appropriate for GA infants. Aneuploid infants with critical congenital heart disease had an adjusted HR of 2.3 (95% CI 1.5-3.6) compared with euploid infants without a structural birth defect. CONCLUSIONS: In this large, population-based study, prematurity, polyhydramnios, and large for gestational age were predictors of increased mortality. Mortality is highly variable among euploid and aneuploid infants with and without structural birth defects and critical congenital heart disease.

Genetic origin of α0-thalassemia (SEA deletion) in Southeast Asian populations and application to accurate prenatal diagnosis of Hb Bart's hydrops fetalis syndrome.

α0-thalassemia of SEA deletion (-SEA) is common among Southeast Asian and Chinese. Using haplotype and phylogenetic analyses, we examined the origin of this defect in Southeast Asian populations. Study was done on both normal and α0-thalassemia alleles in 3 ethnic groups including 96 Thai, 52 Laotian and 21 Cambodian. Five SNPs encompassing the (-SEA) including (rs3760053 T>G), (rs1211375 A>C), (rs3918352 A>G), (rs1203974 A>G) and (rs11248914 C>T) were examined using high-resolution melting assays. It was found that 94.0% of Thai, 100% of Laotian and 100% of Cambodian α0-thalassemia alleles were linked to the same haplotype: the haplotype H4 (AAGC), representing an Asian specific origin. An G allele of the (rs3760053) was found to be in strong linkage disequilibrium with the α0-thalassemia allele in these populations. A multiplex PCR assay was developed to detect simultaneously the (-SEA) allele and genotyping of a linked (rs3760053) to improve accuracy of prenatal diagnosis of α0-thalassemia. Application of this multiplex PCR assay for routine prenatal diagnosis of α0-thalassemia in 12 families revealed a 100% concordant result with conventional gap-PCR assay. Therefore, a single genetic origin is responsible for the spread and high prevalence of the (-SEA) in the region. The multiplex PCR assay developed should provide a double-check PCR system for more accurate diagnosis and allow the monitoring of possible maternal contamination at prenatal diagnosis of this important genetic disorder.