Confirmation of etiology in fetal hydrops by sonographic evaluation of fluid allocation patterns

Prenatal parvovirus B19 infection

Parvovirus B19 (B19V) causes erythema infectiosum, a.k.a., fifth disease. This disease primarily affects children. It is generally self-limiting and subsides after 1-2 weeks. In pregnancy, the virus can cross the placenta and result in a fetal infection. This may lead to severe fetal anemia, hydrops fetalis, a miscarriage, or intrauterine fetal death. The risk of long-term sequelae also appears to be increased. About one-third of pregnant women are not immune to B19V and, therefore, are at risk to contract a primary infection. The seroconversion rate during pregnancy is generally around 1-2%. During a primary infection, maternal-fetal transplacental transmission of B19V occurs in about 30-50% of the cases and the risk of fetal infection increases with advancing gestational age. The risk of severe fetal anemia or hydrops is around 3-4% overall and is around 6-7% if the primary infection occurs before 20 weeks' gestation. Fetal monitoring in women with a primary B19V infection includes regular ultrasound examinations looking for evidence of hydrops fetalis and Doppler measurements of the middle cerebral artery peak velocity. Fetal blood sampling is performed if a significant anemia is suspected and, if such is found, an intrauterine blood transfusion is needed. This article provides an overview of the epidemiology, pathogenesis, clinical manifestations, diagnostic methods, and management of B19V infection during pregnancy.

Isolated non-immune hydrops fetalis: an observational study on complete spontaneous resolution, perinatal outcome, and long-term follow-up

PURPOSE

The aim of our study was to investigate spontaneous resolution and postnatal outcome in non-immune hydrops fetalis (NIHF). We specifically studied NIHF cases that occurred without any other anomalies in the prenatal diagnostic workup, defined as isolated NIHF (iNIHF).

METHODS

To identify iNIHF we retrospectively classified prenatal findings of 700 NIHF singletons, diagnosed in our prenatal referral center between 1997 and 2016. We studied the occurrence of prenatal resolution in iNIHF and linked it to the perinatal outcome. We obtained long-term outcome by contacting the parents, children, and the pediatricians and listed all functional and structural anomalies and temporary logopedic, psychosocial and motoric impairments.

RESULTS

Among 70 iNIHF cases, 54 (77.1%) resolved completely prenatally. The baby-take-home rate was 98.1% in these cases. In contrast, the baby-take-home rate in the subgroup without complete resolution was 25.0%. We achieved pediatric long-term outcome in 27 of 57 survivors (47.4%) of iNIHF with a mean follow-up period of 10.9 years. Among these 27 children, fetal hydrops had completely resolved prenatally in 26 cases and had regressed to a mild effusion in one case. In the pediatric development, two children had significant functional impairment and two children showed recurrent skin edema.

CONCLUSION

Complete spontaneous resolution was the most common intrauterine course of iNIHF in our collective. Completely resolved iNIHF had a favorable perinatal outcome in our study. Our data on the long-term outcomes are consistent with the assumption of an increased rate of functional impairments.

TRIAL REGISTRY

Internal study number of Heinrich-Heine-University, Duesseldorf: 6177R. Date of registration: December 2017.

Human parvovirus B19 infection in a pregnant patient resulting in severe hydrops, foetal death and persistent infection

Human parvovirus B19 (B19V) is the aetiological agent of erythema infectiosum. Primary infection during pregnancy can be transmitted to the foetus and cause foetal abnormalities related to depletion of erythrocyte progenitor cells, including congenital anaemia, hydrops, and foetal death. In this paper we report the detection of B19V infection in a pregnant patient, which onset occurred without appreciable signs and symptoms until she developed inappropriate contractions for gestational age and fluid loss. B19V infection resulted in severe hydrops fetalis with a fatal course for the foetus, while persisted in the mother at least 12 months after foetal death. The objective of this report is to highlight the importance of optimizing B19V diagnosis through early suspicion and testing during pregnancy. Knowing the mother’s immune status before or at the beginning of gestation can contribute, together with early diagnosis, to improve the management of patients at risk.

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.

Identification and management of congenital parvovirus B19 infection

Parvovirus B19 (B19V) infection is well known for its mild, self-limiting clinical presentations in children, such as erythema infectiosum. Approximately 40% of women of childbearing age are susceptible to B19V infection. While maternal B19V infection usually has a good prognosis, B19V can cause severe fetal anaemia and pregnancy loss due to its ability to suppress erythroid progenitor cells. Non-invasive ultrasound monitoring for fetal anaemia is usually performed if maternal seroconversion occurs in the first 20 weeks of gestation, with amniocentesis for fetal infection reserved for those who first present with fetal anaemia or hydrops of unknown cause. Intrauterine transfusion is the standard treatment for severe fetal anaemia and is associated with a significant improvement in survival. However, survivors of hydrops fetalis may have a higher rate of long-term neurodevelopmental complications compared with non-hydropic survivors. This review aims to synthesise published data on the diagnosis, surveillance and outcomes of congenital parvovirus infection to assist clinicians in diagnosing and managing this important condition.

Nonimmune Hydrops Fetalis-Prenatal Diagnosis, Genetic Investigation, Outcomes and Literature Review

The aim of this paper is to review the outcomes and discuss the genetic and non-genetic aetiology of nonimmune hydrops fetalis in order to support differential ultrasound and genetic evaluations and family counselling. This single-centre study includes all cases of nonimmune hydrops fetalis diagnosed prenatally from 2009 to 2019. Two sources of data were used for this study (prenatal and neonatal) to compare and summarise the findings. Data from genetic testing and ultrasound scans were collected. In total, 33 pregnant women with prenatally diagnosed nonimmune hydrops fetalis were studied. The data included 30 cases of singleton (91%) and three cases (9%) of twin pregnancies. There were 14 survivors (43%), seven cases of postnatal deaths (21%), four cases of intrauterine foetal demises (12%), four cases of termination of pregnancy (12%), and four women without a follow up (12%). The total number of chromosomally normal singleton pregnancies was 29 (88%), and 14 foetuses had an anatomical abnormality detected on the ultrasound scan. The chance of survival was the highest in cases of isolated, idiopathic hydrops fetalis, which in most cases was due to an undetectable intrauterine infection. In many cases, the diagnosis could not be established throughout pregnancy. Each case of nonimmune hydrops fetalis should thus be analysed individually.

Outcome of fetuses with congenital parvovirus B19 infection: systematic review and meta-analysis

OBJECTIVE

To explore the outcome of fetuses affected by congenital parvovirus B19 (PB19) infection, with or without signs of hydrops on ultrasound.

METHODS

PubMed, EMBASE and CINAHL databases were searched for studies reporting on prenatal diagnosis and outcome of fetal PB19 infection. The outcomes explored were miscarriage, perinatal death (PND), intrauterine death, neonatal death, spontaneous resolution of hydrops or fetal anemia, need for intrauterine transfusion (IUT), resolution of hydrops or anemia after transfusion, fetal loss following transfusion, abnormal brain scan after birth and abnormal neurodevelopmental outcome. Outcomes were reported according to the presence or absence of signs of hydrops on ultrasound. A subgroup analysis was performed including hydropic and non-hydropic fetuses diagnosed at < 20 weeks and ≥ 20 weeks of gestation. Meta-analyses of proportions and meta-analyses using individual-data random-effects logistic regression were performed to analyze the data.

RESULTS

Thirty-five observational studies were included, involving 611 fetuses affected by PB19 infection. The risks of miscarriage (odds ratio (OR), 11.5; 95% CI, 2.7-49.7) and PND (OR, 4.2; 95% CI, 1.6-11.0) were higher in fetuses with PB19 infection presenting, compared with those not presenting, signs of hydrops on ultrasound. In fetuses affected by hydrops, spontaneous resolution of the infection, defined as disappearance of hydrops without need for IUT, occurred in 5.2% (95% CI, 2.5-8.8%) of cases whereas, in the group of fetuses not affected by hydrops, infection resolved in 49.6% (95% CI, 20.7-78.6%) of cases. IUT was performed in 78.7% (95% CI, 66.4-88.8%) of hydropic and in 29.6% (95% CI, 6.0-61.6%) of non-hydropic fetuses affected by congenital PB19 infection and resolution of the infection after IUT occurred in 55.1% (95% CI, 34.0-75.3%) and in 100% (95% CI, 57.3-100%) of cases, respectively. The risk of fetal loss after IUT was higher in fetuses affected compared with those not affected by hydrops (OR, 9.8; 95% CI, 2.8-34.6). The prevalence of abnormal brain imaging was 9.8% (95% CI, 2.5-21.0%) in fetuses affected and 0.0% (95% CI, 0.0-7.0%) in those not affected by hydrops, whilst the corresponding figures for abnormal neurodevelopmental outcome were 9.5% (95% CI, 2.6-20.2) and 0.0% (95% CI, 0.0-7.5), respectively; however, statistical power to assess these outcomes was inadequate due to the small number of included cases.

CONCLUSIONS

Hydrops is the main determinant of mortality and adverse perinatal outcome in fetuses with PB19 infection. Perinatal outcome in non-hydropic fetuses is generally favorable. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Parvovirus B19 infection during pregnancy and risks to the fetus

Parvovirus B19 infects 1 to 5% of pregnant women, generally with normal pregnancy outcomes. During epidemics, the rate of infection is higher. Major congenital anomalies among offspring of infected mothers are rare, as the virus does not appear to be a significant teratogen. However, parvovirus B19 infection may cause significant fetal damage, and in rare cases, brain anomalies and neurodevelopmental insults, especially if infection occurs in the first 20 weeks of pregnancy. Parvovirus B19 is also an important cause of fetal loss, especially in the second half of pregnancy when spontaneous fetal loss from other causes is relatively rare. Parvovirus B19 infection may affect many fetal organs and can cause severe anemia, following fetal erythroid progenitor cells infection and apoptosis, especially in fetuses, that have shortened half-life of erythrocytes. Severe anemia may cause high output cardiac failure and nonimmune hydrops fetalis. In addition, parvovirus B19 may directly infect myocardial cells and produce myocarditis that further aggravates the cardiac failure. Intrauterine fetal transfusion is commonly used for the treatment of severe fetal anemia with survival rates of 75 to 90% and significant reduction of fetal morbidity. Only 66 cases were evaluated neurodevelopmentally, of which 10 (16%) had slight or severe neurodevelopmental problems. Because parvovirus B19 infection can cause severe fetal morbidity and mortality, it should be part of the routine work-up of pregnant women who have been exposed to the virus or of pregnancies with suspected fetal hydrops. Assessment for maternal infection during pregnancy is especially important during epidemics, when sero-conversion rates are high. Birth Defects Research 109:311-323, 2017. © 2017 Wiley Periodicals, Inc.