Fetal primary hydrothorax is a rare congenital anomaly with an estimated incidence of 1:10,000-15,000 pregnancies, with an unpredictable clinical course, ranging from spontaneous resolution to fetal death. A case of unilateral fetal pleural effusion was diagnosed at 35th week of gestation during a routine ultrasonographic fetal assessment in an uncomplicated pregnancy. A large echogenic collection of fluid was revealed in the right pleural cavity, together with atelectasis of the right lung, as well as displacement of heart and mediastinal structures to the left side of thorax. The patient was also diagnosed with polyhydramnios and there was a disproportion of heart ventricles volume. No other fetal structural abnormalities were detected and there were no symptoms of edema. Fetal biometrics was consistent with the gestational age. In echocardiography, fetal heart was structurally and functionally normal. Screening tests for congenital infections of the fetus were negative. Autoimmune fetal hydrops was excluded after laboratory tests. There was no parents\' consent for the analysis of the karyotype. The patient presented clinical symptoms and was diagnosed with Herpes simplex virus infection and was treated with oral acyclovir. Serial fetal ultrasound exams showed gradual decrease in pleural fluid volume up to complete resolution in 38th week of pregnancy. Pregnancy was ended in the 38th week of gestation with a cesarean delivery of a healthy neonate. It is yet to be determined if there is a direct association between Herpes simplex virus infection in pregnancy and the risk of fetal pleural effusion. The incidence of fetal pleural effusion is low and the neonatal outcome difficult to be predicted. The optimum management of fetal pleural effusion should be subject to further studies to determine the best clinical practice.

Mucopolysaccharidosis (MPS)-VII, called Sly disease, is a lysosomal storage disorder that can cause fetal hydrops, including fetal hydrothorax (FHT). We describe two fetal cases that received thoracoamniotic shunting for FHT, which was later found to be associated with MPS-VII by exome sequencing. Bilateral FHT accompanied by skin edema and ascites was found before 20 weeks of gestation in both cases. One fetus died in utero at 35 weeks of gestation, and the other survived with preterm delivery at 30 weeks of gestation. Both cases inherited compound pathogenic variants of GUSB from parents. Comparison with previously reported primary FHT cases revealed distinct clinical features in MPS-VII-associated FHT: early gestational age at diagnosis (<26 weeks), bilateral effusion, skin edema with ascites, and poor survival. A genetic analysis would be considered for FHT cases, with consideration of shunting when they show early-onset bilateral effusions with skin edema and ascites.

BACKGROUND: We aimed to identify maternal and fetal complications and investigate postnatal and long-term outcomes of fetal hydrothorax (FHT) treated with pleuro-amniotic shunting (shunt).
METHODS: Single-center retrospective observational cohort of shunt cases performed from 2000 to 2021. Risk factors for maternal complications, fetal demise, neonatal death (NND), and postnatal outcomes were identified.
RESULTS: Out of 88 cases, 70 (79.5%) were complicated by hydrops, with an average gestational age (GA) at diagnosis of 27 weeks (range 16-34). In 16 cases, definitive etiology of FHT was identified; five cases of Noonan syndrome and three cases of monogenic disorders diagnosed by whole-exome sequencing (EPHB4, VEGFR3, RASA1). Shunt was performed at an average GA of 28 weeks (20-34), with a dislodgement in 10 cases (11.4%). Maternal: Complications occurred in three cases; survival rate was 76.1% (67/88). Follow-up data were available for 57/67 (85.1%) children. Incidence of severe neurodevelopmental impairment and pneumopathy (broncho dysplasia, persistent pulmonary hypertension of newborn, and asthma) was 5.3% and 8.8%, respectively. Post-treatment persistence of hydrops, FHT associated with genetic syndromes, and GA at birth were risk factors for fetal demise, NND, and postnatal complications.
CONCLUSIONS: In truly isolated FHT, whenever indicated, pleuro-amniotic shunting is a safe procedure associated with good survival rate and long-term outcome.

(1) Background: Severe fetal hydrothorax can be treated by intrauterine thoracoamniotic shunting (TAS). The aim of this study was to assess perinatal outcome and complication rates of TAS with a novel Somatex intrauterine shunt. (2) Methods: This is a single-center retrospective study of all fetuses with hydrothorax treated with TAS using a Somatex shunt between 2014 and 2020. (3) Results: A total of 39 fetuses were included in the study. Mean gestational age at first intervention was 27.4 weeks (range 19-33). Of these, 51% (n = 20) of fetuses had fetal hydrops, which resolved in 65% (13/20) before delivery. The live birth rate was 97% (n = 38), and 74% (n = 29) survived the neonatal period. The rate of postnatal pulmonary complications was high, with 88% of neonates requiring any kind of ventilatory support. There were 23% (n = 9) genetic abnormalities (trisomy 21 and Noonan syndrome). (4) Conclusions: TAS with a Somatex shunt has a high technical success rate, leading to high neonatal survival rates. Pregnancy and neonatal outcome is comparable to TAS for fetal hydrothorax using different shunt types.

To assess short- and long-term outcome in a cohort of fetuses diagnosed with hydrothorax (FHT) which underwent thoracoamniotic shunting in utero, and to examine the antenatal predictors of survival and of survival with normal neurodevelopmental outcome.
This was a retrospective analysis of 132 fetuses that underwent thoracoamniotic shunting at our center between 1991 and 2014. Data were extracted from hospital obstetric and relevant neonatal intensive care and neonatal developmental follow-up databases. Outcomes included survival to discharge and survival with normal neurodevelopmental outcome beyond 18 months. Information on malformations, syndromes and genetic abnormalities were obtained from antenatal, postnatal and pediatric hospital records or by parent report. We compared pregnancy characteristics among those who survived vs non-survivors and among those with normal neurodevelopmental outcome vs those who were abnormal or died. We explored whether there was a trend in survival over the study period.
The mean gestational age at diagnosis of FHT was 25.6 weeks. The fetus was hydropic at diagnosis in 61% of cases, 69% had bilateral effusions and 55% had bilateral shunts inserted. Other diagnoses were present in 24% of cases, two-thirds of which were discovered only postnatally. There were 16 intrauterine and 30 neonatal deaths, with a 65% survival rate overall. The mean gestational age at delivery of liveborns was 35.4 (range, 26.9-41.6) weeks, and 88/116 (76%) were preterm (< 37 weeks). Of 87 liveborn at the treatment center, 75% experienced some respiratory and/or cardiovascular morbidity after birth, many with a lengthy hospital stay (mean, 36 (range, 1-249) days). Overall, 84% of survivors were developmentally normal beyond 18 months and outcomes were better when pleural effusions were isolated, 92% of these cases being neurodevelopmentally normal. There was no trend in survival or neurodevelopmental outcome over time. Despite the presence of FHT and neonatal respiratory issues, most (89%) of the 55 survivors with relevant follow-up had no long-term pulmonary complications. Gestational age at delivery was the only factor independently predictive of both survival and survival with normal neurodevelopmental outcome.
FHT is associated with other pathologies in a quarter of cases and carries a significant risk of prematurity, mortality and neonatal morbidity. The outcome is good in survivors but is best in isolated cases. Predictors of outcome at diagnosis are poor. Future improvement in diagnostics at time of identification of FHT may help to identify those that would benefit most from thoracoamniotic shunting. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Congenital chylothorax is an uncommon condition but represents the main cause of congenital pleural effusion during the neonatal period. It usually appears before birth, both as an isolated disorder or in association with hydrops fetalis, negatively affecting the subsequent neonatal outcome. Prenatal treatment is usually considered to ensure a satisfactory lung development in case of moderate to severe pleural effusion or in the presence of hydrops, although consensus on treatment timing and modalities has not been reached to date. Both medical and surgical therapeutic strategies are available to treat this condition and novel treatment options have been recently attempted with acceptable results in both prenatal and post-natal setting. The heterogeneous clinical presentation of congenital chylothorax together with its rarity, its numerous etiologies and the absence of a highly effective treatment renders the diagnostic and therapeutic approach difficult to standardize. In addition, adequate visualization of the lymphatic system is complex, especially in small neonates, although new promising techniques have been developed lately and may contribute to improved management of this serious but infrequent condition. This review focuses on the current evidence base for the diagnosis and treatment options for congenital chylothorax, suggesting a rational diagnostic and therapeutic approach both in the prenatal and in the neonatal period.

BACKGROUND: Fetal pleural effusions are a rare fetal anomaly that may result from congenital chylothorax. Severe cases lead to chest compression with resulting pulmonary hypoplasia and possible neonatal demise. Fetal thoracoamiontic shunt (TAS) placement may decrease the amount of pleural effusion and improve lung expansion.
METHODS: A 30-year-old primigravida at 29 2/7 weeks\' gestation presented with fetal bilateral pleural effusions with no identifiable genetic or structural abnormalities. TAS placement accomplished decompression of the left fetal chest. The neonate was delivered at 33 3/7 weeks and required minimal respiratory support with no apparent long term complications at discharge.
CONCLUSIONS: This case demonstrated that fetal intervention with TAS placement can improve neonatal outcomes. Referral to an MFM specialist capable of TAS should be considered for isolated fetal bilateral pleural effusion.

BACKGROUND: There have been no previous reports on the postnatal course, especially long-term outcomes, of fetal hydrothorax patients, including those treated with thoracoamniotic shunting (TAS) using a double-basket catheter.The outcomes of cases from a single center are reported.
METHODS: Cases of fetal hydrothorax managed at our center between 2005 and 2015 were enrolled retrospectively. TAS was performed if indicated. Long-term outcomes such as cerebral palsy, developmental disabilities, and others were analyzed.
RESULTS: Ninety-two cases of fetal hydrothorax were included. The causes were primary chylothorax, transient abnormal myelopoiesis, cardiac disease, pulmonary sequestration, mediastinal neoplasm, and infection. TAS was performed in 36 cases. Early neonatal death occurred in 19 cases. The 28-day survival rates for all cases and for TAS cases were 70% (48/69) and 72% (26/36), respectively. Of the cases that underwent TAS, one was treated with home oxygen therapy, one was diagnosed with cerebral palsy and severe intellectual disability, and five were diagnosed with mild or moderate developmental disabilities.
CONCLUSIONS: The results showed that the survival rate and long-term outcomes of cases with hydrothorax have improved as TAS has become more prevalent. The reasons for these results need to be elucidated, and efforts are needed to further improve outcomes.

BACKGROUND: The treatment options for fetal chylothorax include thoracocentesis, thoracoamniotic shunting, and pleurodesis using OK-432. Knowledge on the long-term outcomes after treatment with OK-432 is limited.
OBJECTIVE: The aim of this study was to assess the long-term outcomes of children treated in utero with OK-432.
METHODS: We performed follow-up on pregnancies and children treated in utero with OK-432 between 2003 and 2009 at Copenhagen University Hospital Rigshospitalet for pleural effusions at gestational age (GA) 16+0-21+6 weeks. Anamnestic information, physical examination, pulmonary function test, neuropediatric examination, and intelligence testing using the Wechsler Intelligence Scale were used for evaluation.
RESULTS: Fourteen cases, all chylothorax, were treated with OK-432. None had preterm premature rupture of membranes (PPROM), and the median GA at delivery was 38+5 (24+4-41+5) weeks. Twelve children were eligible for follow-up. The median age at follow-up was 11.4 (7.8-13.8) years. Pulmonary function was normal in all children and the mean full-scale IQ did not differ from that of normal children. Four children had a diagnosed medical condition, attention deficit disorder, or genetic syndrome. The remaining children had normal follow-up.
CONCLUSIONS: Children treated with OK-432 have comparable survival rates and long-term neurodevelopmental outcomes to those treated with thoracoamniotic shunts. There seems to be a lower risk of procedure-related PPROM.

OBJECTIVE: To assess the role of lung size and abnormal Doppler findings in the umbilical artery (UA) in determining the outcomes of fetuses with primary fetal hydrothorax (FHT) associated with hydrops who underwent thoracoamniotic shunting (TAS).
METHODS: This was a retrospective study at a single center. We included cases of primary FHT with hydrops who underwent TAS at our hospital between 2004 and 2016. We assessed the relationship between mortality until 28 days after birth and ultrasound findings, including absent or reversed end-diastolic velocity (AREDV) in the UA and the lung-to-thorax transverse area ratio (LTR), before and after TAS.
RESULTS: Forty-one cases of primary FHT with hydrops underwent TAS. The median (range) gestational age at TAS was 28.5 (19.3-33.8) weeks. Bilateral pleural effusion was observed in 39 cases (95.1%). Among the 41 cases, 19 (46.4%) survived, 11 (26.8%) died in utero, and 11 (26.8%) died in the neonatal period. AREDV in the UA before and after TAS were not associated with mortality (P = 0.32 and 0.47, respectively). The odds ratio for mortality in LTR 0.2-0.3 before TAS was 0.62 (vs LTR < 0.2, P = 0.45) and that in LTR 0.2-0.3 and > 0.3 after TAS were 0.27 and 0.06, respectively (vs LTR < 0.2, P for trend <0.01).
CONCLUSIONS: A larger LTR after TAS was significantly associated with a better prognosis in hydropic primary FHT. The fetal lung size after the procedure may be a prognostic factor of primary FHT.