Pre Gestational Thalassemia Screening in Mainland China: The First Two Years of a Preventive Program.

In this study, we report the experience of a pre gestational thalassemia screening program at a single center in Southern China. Free thalassemia screening, genetic counseling and prenatal diagnosis (PND) for couples planning pregnancy were implemented over a 2-year period. Among a total of 83,062 screened individuals (41,531 couples), the allele frequencies of β-thalassemia (β-thal), - -SEA and - -THAI deletions were 3.79, 5.75 and 0.028%, respectively. Out of the 41,531 couples, 11,039 couples had at least one partner who had a positive screening test; of these, 455 at-risk couples (1.07%) were identified, including 68 (0.16%) for β-thal, 162 (0.39%) for Hb Bart's (γ4) hydrops fetalis, 190 (0.46%) for deletional Hb H (β4) disease and 25 (0.06%) for nondeletional Hb H disease. Of the 455 at-risk couples, 90 were already pregnant and 66 underwent PND at 10-13 weeks' gestation, resulting in 15 affected fetuses. The remaining 355 at-risk couples were still preparing for pregnancy, and they were on the list for follow-up. There is considerable scope for facilitating timely PND through improved organization and screening strategy. The pre pregnancy screening is a feasible and effective approach to thalassemia prevention.