Etiology and Perinatal Outcome of Nonimmune Hydrops Fetalis in Southern China

Routine antenatal molecular testing for α-thalassemia at a tertiary referral hospital in China: ten years of experience

Objective

This study aimed to evaluate the efficacy of α-thalassemia gene testing as a part of an antenatal intervention program over a 10-year period.

Methods

All patients underwent α-thalassemia gene testing, which included the analysis of three types of deletions and mutations. Rare α-thalassemia gene testing was performed using Sanger sequencing, multiplex ligation-dependent probe amplification, and sequencing techniques. Prenatal diagnosis was performed in high-risk couples using chorionic villus sampling or amniocentesis.

Results

From 2010 to 2019, among the 91,852 patients examined, α-thalassemia mutations were identified in 41.78% of patients. The most frequent α0 gene mutation was--SEA, followed by--THAI. Two rare α0-thalassemia gene mutations at --32.8 and --230, were also observed. A total of 2,235 high-risk couples were identified, of which 562 were affected, including three with the--SEA/--THAI genotype and one with the--SEA/--230 genotype. Additionally, prenatal diagnosis revealed four cases of fetal anemia and/or mild edema, along with two cases of severe fetal edema. Chromosome and gene chip results were normal. Thalassemia gene testing showed an αCSα/αCSα genotype in four patients with anemia and/or mild edema, while two patients with severe fetal edema had one--SEA/αCSα genotype and one--SEA/--GX genotype. Using the cut-off points of 74.6 fL and 24.4 pg as criteria for identifying α0-thalassemia carriers and HbH disease, the detection rate of missed diagnoses in high-risk couples is consistent with national guidelines for standards, potentially saving 10,217,700 ¥.

Conclusion

Routine molecular testing for α-thalassemia in high-risk prenatal populations effectively prevented severe α-thalassemia births. Despite the high cost, the cutoff points proposed by this study suggest that implementing screening using a new parameter has the potential to reduce current expenses.

Etiology and outcome of non-immune hydrops fetalis in relation to gestational age at diagnosis and intrauterine treatment

OBJECTIVE

To determine the etiology and outcome of non-immune hydrops fetalis (NIHF) according to gestational age at diagnosis and intrauterine treatment.

STUDY DESIGN

A total of 122 NIHF cases were included. Medical records and ultrasonographic images were reviewed. The etiology, outcome, and intrauterine treatment were assessed.

RESULTS

The etiology was determined in 100 cases, and Hb Bart's disease was the most common. Two cases each of homozygous Southeast Asian ovalocytosis (SAO) and hemoglobin Constant Spring (Hb CS) were found. NIHF diagnosed in early gestation (<24 weeks) had a higher rate of chromosomal abnormalities and fetal demise. Intrauterine treatment was given in 18 cases, and 50% had successful live births.

CONCLUSION

Hb Bart's disease was the most common cause of NIHF. SAO and Hb CS were associated with hydrops. NIHF in gestational age <24 weeks was associated with chromosomal abnormalities and fetal demise. Intrauterine treatment should be offered in selected cases.

The many etiologies of nonimmune hydrops fetalis diagnosed by exome sequencing

OBJECTIVE

To explain the importance of identifying an etiology for the pathological finding of nonimmune hydrops fetalis (NIHF) and to explore the impact of exome sequencing in recurrent NIHF. In addition, we present two cases of pregnancies affected with recurrent NIHF, in which genetic investigation was advantageous.

METHODS

Our study aimed to investigate the genetic background, if available, of all fetuses with NIHF referred to our tertiary medical center from January 2013 to August 2020. We summarized the etiology of NIHF if known, sonographic findings, genetic investigation and the pregnancies' outcomes.

RESULTS

We encountered 144 families with NIHF. Genetic investigation was performed by chromosomal microarray analysis (CMA) in 63 (63/144. 44%) fetuses. Seventeen of 63 (27%) had a positive CMA result. In the negative CMA group, 15 (15/46, 33%) opted for exome sequencing, of which seven exomes were positive (47%). Among these, there were four couples with recurrent pregnancies affected by hydrops. Among the remaining 11 exome investigations for non-recurrent hydrops, another three were diagnostic.

CONCLUSION

As identifying the etiology of the NIHF is an invaluable tool for the prognosis of the pregnancy, exome sequencing can provide further elucidation of the underlying pathogenesis of NIHF. Thus, genetic investigation should be recommended for cases of NIHF.

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.

Placental Chorioangioma with Nonimmune Hydrops Fetalis

A 38-year-old woman was found to have a large placental chorioangioma. The fetus was studied using ultrasound. The pregnancy became complicated by hydrops fetalis, polyhydramnios, and abruptio placenta. The infant delivered at 29 weeks' gestational age. The neonatal course was complicated by nonimmune hydrops fetalis, respiratory distress syndrome, anemia, pulmonary hemorrhage, intraventricular hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia. The infant was discharged home with breastfeeding and off oxygen at 50 days of life. This case represents the multidisciplinary approach to the pregnancy complicated by a large placental chorioangioma and the resulting premature neonate with nonimmune hydrops fetalis.