Objective To explore the cut-off values of mean corpuscular volume(MCV)and mean corpuscular hemoglobin(MCH)for thalassemia screening among pregnant women in Sichuan.Taking genetic testing as the golden standard,the efficacy of MCV or MCH,Hb electrophoresis alone,MCV or MCH combined with Hb electrophoresis in thalassemia screening of pregnant women was evaluated.Methods A total of 554 pregnant women with red blood cell parameters MCV ≤90fl or MCH≤29pg were catagorized in the study group.All 554 pregnant women were tested for Hb electrophoresis and thalassemia gene.At the same time,640 pregnant women who had been excluded thalassemia by genetic test were catagorized in the control group randomly.The Receiver Operating Characteristic(ROC)curves was drawn by software SPSS 23.0 to find out the cut-off values and efficacy of MCV or MCH in screening thalassemia of pregnant women.The efficacy of MCV or MCH,Hb electrophoresis alone,MCV or MCH combined with Hb electrophoresis in thalassemia screen-ing of pregnant women was analyzed.Results A totla of 159 pregnant women were diagnosed as thalassemia by genetic testing(28.7％,159/554).There are 108 cases of α-thalassemia(67.9％,108/159),47 cases of β-thalassemia(29.6％,47/159),and 4 cases ofα-combined β-thalassemia(2.5％,4/159).The most common gene types of α-thalassemia were-α3.7/αα(29.6％,47/159)and--SEA/αα(27.7％,44/159).The most common gene type of β-thalassemia was β-CD17(11.3 percent,18/159).The level of Hb,MCV and MCH of pregnant women with thalassemia was lower than that in the control group.The level of Hb,MCV and MCH of pregnant women with β thalassemia was lower than that with α thalassemia.The level of Hb,MCV and MCH of pregnant women with-SEA/αα thalassemia was lower than that with-α3 7/αα thalassemia.The differences were all statistically significant(P＜0.05).The cut-off value of MCV and MCH for screening thalassemia was 84.4 fl and 28.1pg,respectively.When using 84.4fl as the cut-off value of MCV to screen thalassemia,the sensitivity and specificity was 90％and 78％,respectively.When using 28.1pg as the cut-off value of MCH to screen thalassemia,the sensitivity and specificity was 92％and 81％,respectively.Taking genetic testing as the gold standard,comparing the cut-off value of MCV or MCH with MCV or MCH screening method,when screening the 554 pregnant women with Hb electrophoresis alone,the result showed lower sensitivity and higher rate of missed diagnoses.All differences were statistically sig-nificant(P＜0.05).When screening thalassemia in the study group by using MCV or MCH combined with Hb electrophoresis,the speci-ficity was much lower.All differences were statistically significant(P＜0.05).Conclusion The most common α-thalassemia gene types were-α3.7/αα and--SEA/αα in Sichuan.The most common β-thalassemia gene type was CD17.The appropriate cut-off value of MCV and MCH for screening thalassemia among pregnant women in Sichuan was 84.4 fl and 28.lpg,respectively,with high sen-sitivity and specificitym and low rate of missing diagnoses.Using Hb electrophoresis alone for screening thalassemia kept higher rate of missing diagnoses.While using Hb electrophoresis combined with MCV or MCH for screening thalassemia did not reduce the rate of missed diagnoses.

Objective To explore the cut-off values of mean corpuscular volume(MCV)and mean corpuscular hemoglobin(MCH)for thalassemia screening among pregnant women in Sichuan.Taking genetic testing as the golden standard,the efficacy of MCV or MCH,Hb electrophoresis alone,MCV or MCH combined with Hb electrophoresis in thalassemia screening of pregnant women was evaluated.Methods A total of 554 pregnant women with red blood cell parameters MCV ≤90fl or MCH≤29pg were catagorized in the study group.All 554 pregnant women were tested for Hb electrophoresis and thalassemia gene.At the same time,640 pregnant women who had been excluded thalassemia by genetic test were catagorized in the control group randomly.The Receiver Operating Characteristic(ROC)curves was drawn by software SPSS 23.0 to find out the cut-off values and efficacy of MCV or MCH in screening thalassemia of pregnant women.The efficacy of MCV or MCH,Hb electrophoresis alone,MCV or MCH combined with Hb electrophoresis in thalassemia screen-ing of pregnant women was analyzed.Results A totla of 159 pregnant women were diagnosed as thalassemia by genetic testing(28.7％,159/554).There are 108 cases of α-thalassemia(67.9％,108/159),47 cases of β-thalassemia(29.6％,47/159),and 4 cases ofα-combined β-thalassemia(2.5％,4/159).The most common gene types of α-thalassemia were-α3.7/αα(29.6％,47/159)and--SEA/αα(27.7％,44/159).The most common gene type of β-thalassemia was β-CD17(11.3 percent,18/159).The level of Hb,MCV and MCH of pregnant women with thalassemia was lower than that in the control group.The level of Hb,MCV and MCH of pregnant women with β thalassemia was lower than that with α thalassemia.The level of Hb,MCV and MCH of pregnant women with-SEA/αα thalassemia was lower than that with-α3 7/αα thalassemia.The differences were all statistically significant(P＜0.05).The cut-off value of MCV and MCH for screening thalassemia was 84.4 fl and 28.1pg,respectively.When using 84.4fl as the cut-off value of MCV to screen thalassemia,the sensitivity and specificity was 90％and 78％,respectively.When using 28.1pg as the cut-off value of MCH to screen thalassemia,the sensitivity and specificity was 92％and 81％,respectively.Taking genetic testing as the gold standard,comparing the cut-off value of MCV or MCH with MCV or MCH screening method,when screening the 554 pregnant women with Hb electrophoresis alone,the result showed lower sensitivity and higher rate of missed diagnoses.All differences were statistically sig-nificant(P＜0.05).When screening thalassemia in the study group by using MCV or MCH combined with Hb electrophoresis,the speci-ficity was much lower.All differences were statistically significant(P＜0.05).Conclusion The most common α-thalassemia gene types were-α3.7/αα and--SEA/αα in Sichuan.The most common β-thalassemia gene type was CD17.The appropriate cut-off value of MCV and MCH for screening thalassemia among pregnant women in Sichuan was 84.4 fl and 28.lpg,respectively,with high sen-sitivity and specificitym and low rate of missing diagnoses.Using Hb electrophoresis alone for screening thalassemia kept higher rate of missing diagnoses.While using Hb electrophoresis combined with MCV or MCH for screening thalassemia did not reduce the rate of missed diagnoses.

A 32-year-old female patient with nephrotic syndrome got pregnant during treatments with losartan potassium tablets (50 mg once daily), methylprednisolone tablets(12 mg every other day), and dipyridamole tablets(50 mg once daily). She continued these drugs during pregnancy. Ultrasonographic examination at 24 +2 weeks of gestation indicated oligohydramnios, which lasted until 32 +2 weeks of gestation. The amniotic fluid volume ranged 1.1-3.4 cm, and the amniotic fluid indexes were 1.9-6.9 cm. Losartan and methylprednisolone were discontinued, and nifedipine controlled released tablets (30 mg once daily) were given to reduce blood pressure. Amniotic fluid volume gradually increased to normal. At 34 +4 weeks of gestation, her blood pressure rose to 177/113 mmHg. Preeclampsia was diagnosed. She was treated with magnesium sulfate (IV infusion at a speed of 1 g/h), oral nifedipine controlled released tablets (60 mg once daily) and labetalol (200 mg twice daily). Then her blood pressure was 143/82 mmHg and urinary protein detection was positive (++). At 35 +3 weeks of gestation, a baby boy was delivered by cesarean section, with a body length of 43 cm and a weight of 2 200 g. Neonatal Apgar scores at 1 min and 5 min were both 10, and no birth defects were found. During the follow-up to 24 months of age, his growth and development were good, and intellectual development and physical exercise were normal.

A 32-year-old female patient with nephrotic syndrome got pregnant during treatments with losartan potassium tablets (50 mg once daily), methylprednisolone tablets(12 mg every other day), and dipyridamole tablets(50 mg once daily). She continued these drugs during pregnancy. Ultrasonographic examination at 24 +2 weeks of gestation indicated oligohydramnios, which lasted until 32 +2 weeks of gestation. The amniotic fluid volume ranged 1.1-3.4 cm, and the amniotic fluid indexes were 1.9-6.9 cm. Losartan and methylprednisolone were discontinued, and nifedipine controlled released tablets (30 mg once daily) were given to reduce blood pressure. Amniotic fluid volume gradually increased to normal. At 34 +4 weeks of gestation, her blood pressure rose to 177/113 mmHg. Preeclampsia was diagnosed. She was treated with magnesium sulfate (IV infusion at a speed of 1 g/h), oral nifedipine controlled released tablets (60 mg once daily) and labetalol (200 mg twice daily). Then her blood pressure was 143/82 mmHg and urinary protein detection was positive (++). At 35 +3 weeks of gestation, a baby boy was delivered by cesarean section, with a body length of 43 cm and a weight of 2 200 g. Neonatal Apgar scores at 1 min and 5 min were both 10, and no birth defects were found. During the follow-up to 24 months of age, his growth and development were good, and intellectual development and physical exercise were normal.