Lessons learned from a prenatal diagnosis program for thalassemia in Thailand

To assess the outcome of a thalassemia screening program at community hospitals by determining the proportion of at-risk couples able to obtain a prenatal diagnosis (PND) in relation to gestational age (GA).

We accessed records documenting prenatal screening for thalassemia in lower northern Thailand between January 2014 and December 2016. The proportion of at-risk pregnancies able to obtain a PND was determined and median GAs at the time of at-risk notification were compared. Reasons for failures to obtain PNDs were analyzed.

Among 4633 screen-positive couples, 259 (5.6%) were identified as at-risk while 23 were excluded due to unconfirmed outcomes. Forty-one declined a PND and were excluded from the final calculations. Of the 195 remaining couples, 140 (71.8%) obtained a PND. Their median GA at the time of at-risk notification was 12.4 (5.6-29.1) weeks, which was earlier than the median GA of 17.7 (6.9-34.6) weeks for couples not undergoing PND (P < .001). Risks for various types of thalassemia and GA were associated with the chances of achieving a PND.

In practice, one quarter of couples identified as at-risk were unable to obtain a PND. Time-influencing factors seem to be a major determinant.