OBJECTIVE: To analyze the long-term prognosis of primary and secondary fetal pleural effusion (FPE).
METHODS: We investigated all cases of FPE in a single University hospital (2005-2020). Cases were classified as primary (cases with only pleural effusion) and secondary (cases with other abnormalities such as chromosomal abnormalities or fetal cardiac failure). We retrospectively reviewed the medical records from the time of diagnosis, to assess medical procedures performed, chromosomal test results, and clinical outcomes.
RESULTS: Among 18 027 deliveries, 17 FPEs were identified (primary FPE: 8, secondary FPE: 9). Most primary FPEs were diagnosed in the second trimester of pregnancy, while all secondary FPEs were diagnosed in the third trimester. Secondary FPE was often associated with chromosomal abnormalities, including trisomy 21. The prognosis of pleural effusion caused by trisomy 21 was relatively good, except for cases with TAM. Cases of secondary FPE without trisomy 21 were of cardiac origin, and the neonatal prognosis was poor. The short-term prognosis was better in the primary FPE group, but long-term follow-up identified conditions such as acute encephalitis with refractory, repetitive partial seizures, developmental delay and attention deficit hyperactivity disorder.
CONCLUSIONS: Fetal pleural effusion without the presence of chromosomal abnormalities or morphologies has a good short-term prognosis, but the long-term prognosis is poor. Thus, long-term follow-up is necessary for all cases of fetal pleural effusion.

The aim of this study was to analyse the factors associated with fetal pleural effusion over the past five years in a single institute in the South of China. Between January 2011 and May 2016, 129 foetuses with pleural effusion were referred to the Fetal Medicine Unit in Guangzhou\'s Women and Children\'s Medical Center. Seventy-nine women accepted an invasive procedure to rule out chromosomal abnormalities, fetal anaemia, intrauterine infections or some of the submicroscopic chromosomal abnormalities. Our results showed that chromosomal anomalies occurred in 15.2% (12/79) of cases including 8 Turner syndrome (45, X) (10.1%), 3 trisomy 21 (3.8%) and 1 trisomy 13 (1.3%). Pathological microdeletion or microduplication syndrome occurred in 3 out of 36 (8.3%) prenatal samples with normal karyotype and structural defects. Eight foetuses (10.1%) affected with haemoglobin Bart\'s disease showed pleural effusion at second or third trimester. Two cases (2.5%) were found to have an intrauterine infection. In conclusion, fetal pleural effusion has a close correlation with chromosomal abnormality. CMA may increase the detection rate of chromosomal aberrations, especially for micro-deletion or micro-duplication syndromes. In the South of China, Thalassemia must be considered when a fetal pleural effusion is detected.Impact statementWhat is already known on this subject? The aetiology of fetal pleural effusion includes a chromosomal abnormality, a congenital heart disease, congenital infections and a number of genetic syndromes.What do the results of this study add? This is the first retrospective study to analyse the aetiology of fetal pleural effusion in one institute in the South of China.What are the implications of these findings for clinical practice and/or further research? Besides the chromosomal abnormality, micro-deletion and micro-duplication syndromes were also detected in our study. We feel that thalassemia must be considered when fetal pleural effusion is detected in South China.

OBJECTIVE: Since fetal therapy has been newly developed, objective evaluation of adverse events (AE), all harmful events that are not always related to the procedures, has not yet been adequately reported. We established new terminology and tried to re-evaluate it based on the Japanese prospective thoraco-amniotic shunting (TAS) study.
METHODS: From the literature, all complications that occurred with all fetal therapies were identified as a basis for developing the terminology. Grading was set from 0 to 5. Grade 3 was defined as the need for invasive treatment, such as surgery. Grade 4 was defined as life-threatening, and Grade 5 was defined as death of the mother or fetus. Then, one series of TAS that we had already reported was re-evaluated, including 24 cases with 37 procedures and 200 opportunities those could be evaluated AE after procedures.
RESULTS: Grade 4 preterm rupture of the membranes was reported in only 1 of 24 cases. Catheter displacement was reported in 7, 2 and 11 cases, of Grades 1, 2 and 3, respectively. It was found that the double-basket catheter had some association with catheter displacement, but it was clear that there were no life-threatening AE.
CONCLUSIONS: Newly developed AE criteria are now available for fetal therapy. They will contribute to the objective evaluation of AE of new fetal therapies in the future.