Introduction

Hemoglobinopathies are among the most common inherited diseases worldwide. Countries with a high prevalence of carriers have implemented population-based premarital screening to prevent the disease. In Turkey, a national hemoglobinopathy control program (NHCP) was officially launched in 2003. This program includes carrier screening, which is preceded by genetic counseling, public education, and prenatal diagnosis (PND).

However, a study conducted among registered patients in the National Hemoglobinopathy Registry (NHR) of the Turkish Hematology Association between 2011 and 2015 (Turk J Hematol 2018;35:12-18) did not show a consistent decline in the number of affected births over time in Turkey. Since those times, Turkey has experienced a significant influx of over 3 million Syrian migrants. Furthermore, a substantial number of patients of all ages have been added to the NHR over the last decade. This study examines the changing trends in the births of affected children in Turkey, utilizing data from the recent NHR database.

Methods

The demographics of patients included in the NHR were evaluated. We collected data on patients born in each year from 2000 onward, noting that those born since 2005 represent the affected births following the implementation of NHCP. Patients of other nationalities were evaluated separately, as it remains unclear whether they were born in Turkey. All births with hemoglobinopathies over 25 years, between 2000 and 2024, were evaluated by dividing the time into 5-year periods, with the first 5 years representing the period before the establishment of the NHCP. The latter data was projected for the following five-year periods between 2005 and 2024 and then compared to the actual data from the same period. The information regarding premarital screening, genetic counseling, and PND was collected from the parents.

Results

The NHR includes a total of 5,075 patients, comprising 4,255 with thalassemia and 820 with sickle cell disorders. Among these patients, 372 are immigrants. Notably, 38% of the registered Turkish citizen patients (n = 1,784) were born between 2005 and 2024, and 1,629 of those had thalassemia. Between 2000 and 2004, a total of 718 births were recorded. The average number of births each year was 144 ± 6 (median 146). Over the following five-year periods, a gradual decline in the average number of births was observed as; 2005-2009, 133 ± 12 (median 142), 2010-2014, 113 ± 6 (median 114), 2015-2019, 85 ± 7 (median 88), and 2020-2024, 26 ± 11 (median 28). The significant decline in the final five-year period requires caution, as not all pediatric centers have updated their registries between 2020 and 2024. In contrast, out of 372 patients from other nationalities, 308 were born between 2005 and 2024, with a gradual increase in births at five-year intervals, peaking with the highest number (n = 114) during the period from 2015 to 2019.

Only 32% of parents of patients born after 2004 underwent premarital screening. The screening rate was much lower among migrant couples, at just 5%. Of those who were screened, 60% received information about being at-risk couples to have affected children. However, only 30.5% of these couples opted for prenatal diagnosis (PND), yet went on to have their babies, even though the law permitted the termination of pregnancies involving affected babies. Additionally, 21% of parents reported receiving inaccurate results for their carrier status, while 19% did not receive any information about the screening at all.

ConclusionsAn analysis of the registry reveals that the NHCP has achieved a 37% reduction in the number of births with hemoglobinopathies over the past 20 years, demonstrating a consistent and gradual decline since its inception. However, it is essential to address the program's shortcomings that may hinder even greater success. Additionally, an urgent strategy is needed for the migrated population of reproductive age, taking into account the societal values of that community.

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2025
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