Risk factors associated with fetal pleural effusion in prenatal diagnosis: a retrospective study in a single institute in Southern China.

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 statement The aetiology of fetal pleural effusion includes a chromosomal abnormality, a congenital heart disease, congenital infections and a number of genetic syndromes. This is the first retrospective study to analyse the aetiology of fetal pleural effusion in one institute in the South of China. 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.