A Retrospective Study of Prenatal Diagnosis for Thalassemia in 58,891 Couples from Guangxi.

Objective This study aimed to evaluate a comprehensive prenatal diagnosis service and its effectiveness in reducing the birth of children with severe thalassemia in Guangxi, China. Methods Prenatal diagnosis was offered to 58,891 at-risk couples from Guangxi. Fetal samples were collected via chorionic villus sampling, amniocentesis, and cordocentesis. DNA analysis was performed using polymerase chain reaction, reverse dot blot assay, multiplex ligation-dependent probe amplification, and DNA sequencing. Results From 2018 to 2023, the proportion of umbilical cord blood samples among all tested samples declined annually, while the proportion of chorionic villus samples increased significantly (χ2=382.550, P<0.0001). A total of 71 distinct α-thalassemia mutations and 123 different β-thalassemia mutations were identified among the fetuses. The most common α-thalassemia mutation was --SEA, followed by -α3.7. Hb Bart's hydrops fetalis syndrome was detected in 4,434 cases (12.22%). For β-thalassemia, the most frequent mutation was CD41-42, followed by CD17; 948 homozygous or compound heterozygous cases were identified. The majority of couples whose fetuses were diagnosed with β-thalassemia major opted for pregnancy termination under medical guidance. Postnatal follow-up confirmed all pregnancy outcomes. Conclusion The prenatal diagnostic strategy implemented in Guangxi has effectively facilitated early diagnosis and significantly reduced the incidence of infants born with severe thalassemia.