Prenatal exposure to maternal β-thalassemia minor and the risk for long-term hematologic morbidity in the offspring: A population-based cohort study

New logarithm-based discrimination formula for differentiating thalassemia trait from iron deficiency anemia in pregnancy

BACKGROUND

Thalassemia trait (TT) and iron deficiency anemia (IDA) are the most common conditions of microcytic hypochromic anemia (MHA) in pregnant women. Accurate discrimination between TT and IDA is an important issue, and better methods are urgently needed. Although considerable RBC formulas and indices have been developed since 1973, distinguishing between IDA and TT is still a challenging problem due to the diversity of various anemic populations. To address this problem, we assessed the diagnostic function of 43 different differential formulas in patients with microcytic anemia by using accuracy measures and recommending a new log-based differential formula.

METHODS

The data of 430 pregnant women (229 with TT and 201 with IDA) were enrolled, and 44 formula performances were evaluated with receiver operating characteristic (ROC) analysis.

RESULTS

The newly introduced logarithm-based formula XS-1 performs better than the general discriminant index with sensitivity and specificity of 82.10 and 89.05, which are better than other formulas. In the pregnant population, the Shine and Lal and Roth..SVM. formulas have shown excellent performance, while other formulas showed poorer discriminative abilities in our study than in the original authors.

CONCLUSION

The logarithm-based formula XS-1 can be used to screen thalassemia and iron deficiency anemia during the first trimester. Considering the particularity of pregnancy, medical personnel in different regions should choose a screening formula similar to that of the local region and population when identifying thalassemia in pregnancy. Any formula should be independently verified locally before use. For the convenience of the health care team and experimental scientists, a web-based tool has been established at http://yyy.yiyiy.top/XS-1/ by which users can easily get their desired screening test result without going through the underlying mathematical and computational details.

Pregnancy outcomes among women affected with thalassemia traits

OBJECTIVE

To compare the maternal and perinatal outcomes between a group of pregnant women diagnosed with thalassemia traits and normal controls.

STUDY DESIGN

A retrospective cohort study was conducted on singleton pregnant women affected and unaffected by thalassemia traits who attended an antenatal care clinic and delivered in Siriraj Hospital. Thalassemia status for all subjects was diagnosed by hemoglobin typing and/or DNA analysis. Patient charts were reviewed from January 2007 to December 2018. The control participants were randomly selected from the same period, with a control-case ratio of around 1:1.

RESULTS

Overall, 1288 women with thalassemia traits (348 with α thal-1 trait, 424 with β thal trait and 516 with HbE trait) and 1305 women in the control group were recruited. Baseline characteristics of both groups were similar, with the exception that the hematocrit level in the first trimester in the thalassemia trait group was significantly lower than that in the control group (34.8 ± 3.4% VS 36.9 ± 3.0%; p < 0.001). The prevalence of pregnancy-induced hypertension (PIH) was higher in the thalassemia trait group, at 6.9% VS 4.7% in the control group; p = 0.018. When subgroups were analyzed between each thalassemia trait, the number of maternal anemias in the first and third trimester was higher for all thalassemia traits compared to the normal group. The β thal and HbE traits increased the risk of PIH, with a relative risk (RR) = 1.67 and 1.66, respectively.

CONCLUSIONS

Thalassemia traits minimally but significantly increase the risk of hypertensive disorders and maternal anemia. In addition, physiological changes during pregnancy may worsen the severity of anemia in the pregnant women with thalassemia traits.

Effects of thalassemia on pregnancy outcomes of women with gestational diabetes mellitus

AIM

To explore the effect of thalassemia on pregnancy outcomes of women with gestational diabetes mellitus (GDM).

METHODS

This retrospective study reviewed the medical records of women with GDM delivered at the Chongqing Maternal and Child Health Hospital in China between July 2017 and December 2020. The live singleton pregnancies with α or β-thalassemia were identified as the thalassemia group, included α-thalassemia subgroup and β-thalassemia subgroup, whereas pregnant women without thalassemia were randomly selected as the non-thalassemia group according to a control-to-case ratio of 10:1 by computerized randomization. Logistic regression analyses were used to explore the potential association between thalassemia and pregnancy outcomes.

RESULTS

A total of 223 pregnant women with GDM and thalassemia were analyzed, including women with α-thalassemia (n = 143) and β-thalassemia (n = 80). There were no significant differences in the incidence of adverse neonatal outcomes such as preterm birth and low-birth weight among groups. However, among pregnancy complications, significant differences were detected in the incidence of placenta increta, polyhydramnios, and postpartum anemia between the thalassemia group and the non-thalassemia group. Logistic regression results indicated that β-thalassemia increased the risk of polyhydramnios (odds ratio [OR] = 3.95, 95% confidence interval [CI]: 1.14-13.65, p = 0.030) and chorioamnionitis (OR = 3.61, 95%CI: 1.04-12.49, p = 0.043) compared with the non-thalassemia group.

CONCLUSION

In our study, thalassemia did not increase adverse neonatal outcomes, but β-thalassemia increased the risk of pregnancy complications, including polyhydramnios and chorioamnionitis.